Forests

27 pages, 3310 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of Correction Algorithms for Sentinel-2 Images Implemented in Google Earth Engine for Use in Land Cover Classification in Northern Spain

by Iyán Teijido-Murias, Marcos Barrio-Anta and Carlos A. López-Sánchez

Forests 2024, 15(12), 2192; https://doi.org/10.3390/f15122192 - 12 Dec 2024

Viewed by 1065

Abstract

This study examined the effect of atmospheric, topographic, and Bidirectional Reflectance Distribution Function (BRDF) corrections of Sentinel-2 images implemented in Google Earth Engine (GEE) for use in land cover classification. The study was carried out in an area of complex orography in northern [...] Read more.

This study examined the effect of atmospheric, topographic, and Bidirectional Reflectance Distribution Function (BRDF) corrections of Sentinel-2 images implemented in Google Earth Engine (GEE) for use in land cover classification. The study was carried out in an area of complex orography in northern Spain and made use of the Spanish National Forest Inventory plots and other systematically located plots to cover non-forest classes. A total of 2991 photo-interpreted ground plots and 15 Sentinel-2 images, acquired in summer at a spatial resolution of 10–20 m per pixel, were used for this purpose. The overall goal was to determine the optimal level of image correction in GEE for subsequent use in time series analysis of images for accurate forest cover classification. Particular attention was given to the classification of cover by the major commercial forest species: Eucalyptus globulus, Eucalyptus nitens, Pinus pinaster, and Pinus radiata. The Second Simulation of the Satellite Signal in the Solar Spectrum (Py6S) algorithm, used for atmospheric correction, provided the best compromise between execution time and image size, in comparison with other algorithms such as Sentinel-2 Level 2A Processor (Sen2Cor) and Sensor Invariant Atmospheric Correction (SIAC). To correct the topographic effect, we tested the modified Sun-canopy-sensor topographic correction (SCS + C) algorithm with digital elevation models (DEMs) of three different spatial resolutions (90, 30, and 10 m per pixel). The combination of Py6S, the SCS + C algorithm and the high-spatial resolution DEM (10 m per pixel) yielded the greatest precision, which demonstrated the need to match the pixel size of the image and the spatial resolution of the DEM used for topographic correction. We used the Ross-Thick/Li-Sparse-Reciprocal BRDF to correct the variation in reflectivity captured by the sensor. The BRDF corrections did not significantly improve the accuracy of the land cover classification with the Sentinel-2 images acquired in summer; however, we retained this correction for subsequent time series analysis of the images, as we expected it to be of much greater importance in images with larger solar incidence angles. Our final proposed dataset, with image correction for atmospheric (Py6S), topographic (SCS + C), and BRDF (Ross-Thick/Li-Sparse-Reciprocal BRDF) effects and a DEM of spatial resolution 10 m per pixel, yielded better goodness-of-fit statistics than other datasets available in the GEE catalogue. The Sentinel-2 images currently available in GEE are therefore not the most accurate for constructing land cover classification maps in areas with complex orography, such as northern Spain. Full article

(This article belongs to the Special Issue Application of Remote Sensing and Geographic Information Systems for Natural Resource Management of Forest Ecosystems)

► Show Figures

Figure 1

21 pages, 1243 KiB

Open AccessEditor’s ChoiceReview

Prospects for Oak Cultivation in Europe Under Changing Environmental Conditions and Increasing Pressure from Harmful Organisms

by Aneta Lyubenova, Marlena Baranowska, Audrius Menkis, Kateryna Davydenko, Justyna Nowakowska, Piotr Borowik and Tomasz Oszako

Forests 2024, 15(12), 2164; https://doi.org/10.3390/f15122164 - 8 Dec 2024

Viewed by 1275

Abstract

It is assumed that climate change (global warming) worsens the living conditions for conifers and at the same time favours the cultivation of deciduous trees, including oaks. In fact, in Poland, for example, many more oaks are now being planted as forest-forming tree [...] Read more.

It is assumed that climate change (global warming) worsens the living conditions for conifers and at the same time favours the cultivation of deciduous trees, including oaks. In fact, in Poland, for example, many more oaks are now being planted as forest-forming tree species than in the 1980s and 1990s. However, the monitoring of the health status of European forests (according to the International Co-operation Project) does not confirm these optimistic assumptions, and oak has been cited as one of the most damaged tree species in terms of defoliation in recent decades. The prospects for oak cultivation in European forestry are therefore a combination of abiotic conditions and biotic damage factors. This review article focuses in particular on the new threats posed by pathogenic organisms causing emerging diseases. These include newly identified bacteria responsible for the so-called Acute Oak Decline (AOD), oomycetes (especially those specialised in damaging fine roots, such as Phytophthora quercina T.Jung) and semi-parasites of the genus Loranthus. At the same time, the pressure from commonly observed insects and fungi described in connection with the complex syndrome of oak decline, which is divided into predisposing, inciting, and contributing factors (according to Manion’s disease spiral), has not abated. Therefore, international, interdisciplinary research (such as that proposed in Oakland) is needed, using modern technologies (RS remote sensing) based on the comparison of satellite images (from different years), not only to inventory the most valuable oak stands in Europe (microrefugia) but also to identify trends in changes in their condition and biodiversity. As RS has its limitations (e.g., resolution), aerial monitoring should be complemented by quantitative and qualitative inventory from the ground, e.g., monitoring of the presence of soil microorganisms using effective molecular biological methods (e.g., Next-Generation Sequencing NGS). Full article

(This article belongs to the Section Forest Health)

► Show Figures

Figure 1

15 pages, 3144 KiB

Open AccessEditor’s ChoiceArticle

Effect of Inoculation with Rhizosphere Phosphate-Solubilizing Bacteria on the Growth and Physiological Characteristics of Parashorea chinensis

by Zhongheng Hu, Shuang Wei, Wannian Li, Tong Wu, Saif Ullah and Mei Yang

Forests 2024, 15(11), 1932; https://doi.org/10.3390/f15111932 - 1 Nov 2024

Viewed by 1218

Abstract

Given the challenges of slow growth and low survival rates in the early stages of Parashorea chinensis cultivation, identifying sustainable methods to enhance seedling performance is critical for successful reforestation and conservation efforts. This study aimed to address these by investigating the growth-promoting [...] Read more.

Given the challenges of slow growth and low survival rates in the early stages of Parashorea chinensis cultivation, identifying sustainable methods to enhance seedling performance is critical for successful reforestation and conservation efforts. This study aimed to address these by investigating the growth-promoting effects of phosphate-solubilizing bacteria (PSB). One-year-old seedlings of P. chinesis were inoculated with PSB strains isolated from the rhizosphere soil of Parashorea chinensis H. Wang plantations Y3, W5, H8, and a mixed strain (Mix), with inoculated seedling as a control (CK). The effects of inoculation on seedling growth, photosynthetic physiology, plant nutrient status, and physiological indicators were comprehensively evaluated. Results showed that PSB inoculation increased seedling height and basal diameter growth of P. chinensis, with an increase of 1.56 cm and 0.53 mm compared to CK, respectively, though the differences were not significant. The Mix treatment significantly improved photosynthesis, with increases in net photosynthetic rate (106.3%), transpiration rate (93.89%), and intercellular CO₂ concentration (75.51%) compared to CK. Nutrient levels including total nitrogen, total phosphorus, and total potassium were significantly increased by 15.98%, 25.54%, and 32.12%, respectively, in the Mix treatments compared to CK. Moreover, stress resistance also improved, with higher proline content, soluble sugar, and soluble protein levels. Antioxidant enzyme activities (SOD, CAT, and POD) were increased by 9.83%, 23.66%, and 292.32%, respectively, while MDA content was significantly reduced by 69.01%. The mixed strain treatment also significantly increased acid phosphatase activity by 111.88%. In conclusion, PSB inoculation, particularly with the mixed strain, promoted growth and nutrient uptake photosynthetic efficiency and stress resistance in P. chinensis seedlings, offering a promising biotechnological solution for improving seedling performance. Full article

(This article belongs to the Special Issue Sustainable Forest Fertilization Strategies: Impact on Soil Quality, Ecosystem Health and Productivity)

► Show Figures

Figure 1

19 pages, 6528 KiB

Open AccessEditor’s ChoiceArticle

Estimation of Tree Diameter at Breast Height from Aerial Photographs Using a Mask R-CNN and Bayesian Regression

by Kyeongnam Kwon, Seong-kyun Im, Sung Yong Kim, Ye-eun Lee and Chun Geun Kwon

Forests 2024, 15(11), 1881; https://doi.org/10.3390/f15111881 - 25 Oct 2024

Viewed by 3168

Abstract

A probabilistic estimation model for forest biomass using unmanned aerial vehicle (UAV) photography was developed. We utilized a machine-learning-based object detection algorithm, a mask region-based convolutional neural network (Mask R-CNN), to detect trees in aerial photographs. Subsequently, Bayesian regression was used to calibrate [...] Read more.

A probabilistic estimation model for forest biomass using unmanned aerial vehicle (UAV) photography was developed. We utilized a machine-learning-based object detection algorithm, a mask region-based convolutional neural network (Mask R-CNN), to detect trees in aerial photographs. Subsequently, Bayesian regression was used to calibrate the model based on an allometric model using the estimated crown diameter (CD) obtained from aerial photographs and analyzed the diameter at breast height (DBH) data acquired through terrestrial laser scanning. The F1 score of the Mask R-CNN for individual tree detection was 0.927. Moreover, CD estimation using the Mask R-CNN was acceptable (rRMSE = 10.17%). Accordingly, the probabilistic DBH estimation model was successfully calibrated using Bayesian regression. A predictive distribution accurately predicted the validation data, with 98.6% and 56.7% of the data being within the 95% and 50% prediction intervals, respectively. Furthermore, the estimated uncertainty of the probabilistic model was more practical and reliable compared to traditional ordinary least squares (OLS). Our model can be applied to estimate forest biomass at the individual tree level. Particularly, the probabilistic approach of this study provides a benefit for risk assessments. Additionally, since the workflow is not interfered by the tree canopy, it can effectively estimate forest biomass in dense canopy conditions. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

► Show Figures

Figure 1

22 pages, 4658 KiB

Open AccessEditor’s ChoiceArticle

Development and Application of Microsatellite Markers for Genetic Diversity Assessment and Construction of a Core Collection of Myrciaria dubia (Kunth) McVaugh Germplasm from the Peruvian Amazon

by Juan C. Castro, Stalin J. Vasquez-Guizado, Bianca E. Vigil, Francisco Ascue, Naysha Rojas-Villa, Jae D. Paredes, Marianela Cobos, Carlos G. Castro, Daniel E. Motta, Pedro M. Adrianzén, Sixto A. Imán and J. Dylan Maddox

Forests 2024, 15(11), 1873; https://doi.org/10.3390/f15111873 - 25 Oct 2024

Viewed by 3742

Abstract

The Amazonian shrub Myrciaria dubia (camu-camu) produces vitamin C-rich fruits of growing commercial interest. However, sustainable utilization requires assessment and protection of the genetic diversity of the available germplasm. This study aimed to develop and apply microsatellite markers to assess genetic diversity and [...] Read more.

The Amazonian shrub Myrciaria dubia (camu-camu) produces vitamin C-rich fruits of growing commercial interest. However, sustainable utilization requires assessment and protection of the genetic diversity of the available germplasm. This study aimed to develop and apply microsatellite markers to assess genetic diversity and construct a core collection of M. dubia germplasm from the Peruvian Amazon. Sixteen polymorphic microsatellite loci were developed using an enrichment approach. The evaluation of 336 genotypes from 43 accessions of the germplasm bank, originating from eight river basins, was conducted using these newly developed markers. Genetic diversity parameters, including observed and expected heterozygosity, were calculated. Analysis of molecular variance (AMOVA) was performed to assess the distribution of genetic variation within and among accessions and river basins. Bayesian clustering analysis was employed to infer population structure. A core collection was constructed to maximize allelic richness. High genetic diversity was observed, with heterozygosity values ranging from 0.468 to 0.644 (observed) and 0.684 to 0.817 (expected) at the river basin level. AMOVA indicated significant genetic variation within (73–86%) compared to among (14–27%) accessions and river basins. Bayesian clustering detected ten genetic clusters, with several degrees of admixture among river basins, except for the genetically homogeneous Putumayo River basin. A core collection comprising 84 plant genotypes (25% of the full collection) was established, representing 90.82% of the overall allelic diversity. These results have important implications for M. dubia conservation strategies and breeding programs, in demonstrating a need for genetic connectivity between populations but preserving unique genetic resources in isolated basins. These results validate the expected levels of diversity and population subdivision in a crop and stress the need to secure genetically diverse germplasms, underscoring the importance of thorough genetic characterization for ex situ germplasm management. Full article

(This article belongs to the Special Issue Biodiversity in Forests: Management, Monitoring for Conservation)

► Show Figures

Figure 1

31 pages, 4870 KiB

Open AccessEditor’s ChoiceArticle

Factors Influencing the Faunal Recolonization of Restored Thornscrub Forest Habitats

by Audrey J. Hicks, Jerald T. Garrett and Christopher A. Gabler

Forests 2024, 15(10), 1833; https://doi.org/10.3390/f15101833 - 20 Oct 2024

Viewed by 1274

Abstract

Tamaulipan thornscrub forests (thornforests) have high ecological and economic values, yet over 90% of these forests have been lost, and they remain threatened, making them a conservation hotspot. For decades, federal, state, NGO, and corporate entities have been acquiring land and actively or [...] Read more.

Tamaulipan thornscrub forests (thornforests) have high ecological and economic values, yet over 90% of these forests have been lost, and they remain threatened, making them a conservation hotspot. For decades, federal, state, NGO, and corporate entities have been acquiring land and actively or passively restoring these forests, but results have been mixed and seldom monitored. This study characterized and quantified faunal communities of restored thornforest habitats in south Texas and examined the relationships between restored faunal communities and key site characteristics and environmental factors. We surveyed and analyzed mammal, bird, Lepidoptera, and herptile communities within 12 restored sites in the Lower Rio Grande Valley of southernmost Texas, USA. The site and environmental factors that influenced animal community composition, richness, diversity, and abundance varied widely among taxa. Time since restoration began and method of restoration influenced many community metrics, whereas patch size and extent of isolation influenced few. Several aspects of restored plant communities were influential, especially ground layer diversity, and high invasive plant cover negatively impacted many animal community metrics. If actively restoring a site, efforts to control invasive plants, foster native plant diversity, and provide a nearby water source are likely the most effective ways to promote faunal recolonization. Full article

(This article belongs to the Section Forest Biodiversity)

► Show Figures

Figure 1

22 pages, 6601 KiB

Open AccessEditor’s ChoiceArticle

Turbulent Energy and Carbon Fluxes in an Andean Montane Forest—Energy Balance and Heat Storage

by Charuta Murkute, Mostafa Sayeed, Franz Pucha-Cofrep, Galo Carrillo-Rojas, Jürgen Homeier, Oliver Limberger, Andreas Fries, Jörg Bendix and Katja Trachte

Forests 2024, 15(10), 1828; https://doi.org/10.3390/f15101828 - 20 Oct 2024

Viewed by 1073

Abstract

High mountain rainforests are vital in the global energy and carbon cycle. Understanding the exchange of energy and carbon plays an important role in reflecting responses to climate change. In this study, an eddy covariance (EC) measurement system installed in the high Andean [...] Read more.

High mountain rainforests are vital in the global energy and carbon cycle. Understanding the exchange of energy and carbon plays an important role in reflecting responses to climate change. In this study, an eddy covariance (EC) measurement system installed in the high Andean Mountains of southern Ecuador was used. As EC measurements are affected by heterogeneous topography and the vegetation height, the main objective was to estimate the effect of the sloped terrain and the forest on the turbulent energy and carbon fluxes considering the energy balance closure (EBC) and the heat storage. The results showed that the performance of the EBC was generally good and estimated it to be 79.5%. This could be improved when the heat storage effect was considered. Based on the variability of the residuals in the diel, modifications in the imbalances were highlighted. Particularly, during daytime, the residuals were largest (56.9 W/m² on average), with a clear overestimation. At nighttime, mean imbalances were rather weak (6.5 W/m²) and mostly positive while strongest underestimations developed in the transition period to morning hours (down to −100 W/m²). With respect to the Monin–Obukhov stability parameter ((z − d)/L) and the friction velocity (u*), it was revealed that the largest overestimations evolved in weak unstable and very stable conditions associated with large u* values. In contrast, underestimation was related to very unstable conditions. The estimated carbon fluxes were independently modelled with a non-linear regression using a light-response relationship and reached a good performance value (R² = 0.51). All fluxes were additionally examined in the annual course to estimate whether both the energy and carbon fluxes resembled the microclimatological conditions of the study site. This unique study demonstrated that EC measurements provide valuable insights into land-surface–atmosphere interactions and contribute to our understanding of energy and carbon exchanges. Moreover, the flux data provide an important basis to validate coupled atmosphere ecosystem models. Full article

(This article belongs to the Section Forest Meteorology and Climate Change)

► Show Figures

Figure 1

20 pages, 4862 KiB

Open AccessEditor’s ChoiceReview

Charting the Research Status for Bamboo Resources and Bamboo as a Sustainable Plastic Alternative: A Bibliometric Review

by Hanjiao Zhang, Xu Zhang, Yulong Ding, Feiyi Huang, Zhuoyu Cai and Shuyan Lin

Forests 2024, 15(10), 1812; https://doi.org/10.3390/f15101812 - 16 Oct 2024

Cited by 1 | Viewed by 1813

Abstract

With the increasing pollution caused by plastic products, people’s awareness of environmental protection has gradually increased. Based on the advantages of China’s bamboo resources and bamboo industry, the International Network for Bamboo and Rattan launched the ‘Utilizing bamboo as a sustainable alternative to [...] Read more.

With the increasing pollution caused by plastic products, people’s awareness of environmental protection has gradually increased. Based on the advantages of China’s bamboo resources and bamboo industry, the International Network for Bamboo and Rattan launched the ‘Utilizing bamboo as a sustainable alternative to plastic’ initiative in November 2022 to accelerate the implementation of the United Nations 2030 Agenda for Sustainable Development. This initiative provides a nature-based solution for global sustainable development, which will have a profound impact on promoting global green development, industrial science and technology, social services, cultural exchanges, and other fields. It has a huge market capacity and application potential. This study aims to understand the research status, hotspots, development trends, and prospects of this initiative. WoS and China National Knowledge Infrastructure (CNKI) were searched for the relevant literature on ‘utilizing bamboo as a sustainable alternative to plastic bamboo as plastic’ and ‘bamboo resources’ from the establishment of the database to 2024. Bibliometric methods and VOSviewer were used to analyze 1855 literatures with the above two keywords published in the Web of Science core set database from 2000 to 2024. A visual analysis was performed on the number of publications, national research institutions, researchers, number of citations, and research topics of the literature. For example, China, the United States, and India ranked in the top three in terms of the number of articles published, with 1103, 267, and 167, respectively. China had the highest number of citations, reaching 26,607. At the same time, the literature with ‘bamboo’ as the keyword in CNKI was analyzed to understand the species of bamboo currently studied. A literature investigation was carried out around the resource cultivation of the bamboo industry in our country, and it was found that the research on ‘use bamboo as plastic’ and ‘bamboo resources’ had been valued by scholars at home and abroad, and had formed a relatively stable research group. Using scientific and technological innovation to improve the product quality of ‘bamboo instead of plastic’, expanding its application scope and market demand, and realizeing the sustainable industry development of ‘bamboo instead of plastic’ is the current research hotspot and the future development direction. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

► Show Figures

Figure 1

37 pages, 2536 KiB

Open AccessEditor’s ChoiceReview

Multidimensional Exploration of Wood Extractives: A Review of Compositional Analysis, Decay Resistance, Light Stability, and Staining Applications

by Chenggong Gao, Xinjie Cui and Junji Matsumura

Forests 2024, 15(10), 1782; https://doi.org/10.3390/f15101782 - 10 Oct 2024

Viewed by 1329

Abstract

Extractives, which naturally evolve as fundamental defense mechanisms in wood against environmental stresses, hold an essential place in the field of wood conservation science. Despite their low content in woody substrates, extractives are chemically complex and can be extracted accurately by solvents with [...] Read more.

Extractives, which naturally evolve as fundamental defense mechanisms in wood against environmental stresses, hold an essential place in the field of wood conservation science. Despite their low content in woody substrates, extractives are chemically complex and can be extracted accurately by solvents with different polarities, covering key components such as aliphatic, terpenoid, and phenolic compounds. The application of solvent extraction allows for the effective recovery of these extracts from forestry waste, thereby creating new opportunities for their reuse in wood modification and enhancing the economic value and potential applications of forestry waste. In the wood industry, extractives not only act as efficient preservatives and photo-stabilizers, significantly improving the decay resistance and photodegradation resistance of wood, but also serve as ideal dyes for fast-growing wood due to their abundant natural colors, which lend the product a distinct aesthetic appeal. The aim of this paper is to provide a comprehensive review of the origin and distribution characteristics of wood extractives and to examine the impact of solvent selection on extraction efficiency. At the same time, the mechanism of extractives in enhancing wood decay resistance and slowing down photodegradation is deeply analyzed. In addition, specific examples are presented to illustrate their wide utilization in the wood industry. This is intended to provide references for research and practice in related fields. Full article

(This article belongs to the Section Wood Science and Forest Products)

► Show Figures

Figure 1

15 pages, 7775 KiB

Open AccessEditor’s ChoiceArticle

Forest Restoration Thinning Has Minimal Impacts on Surface Soil Carbon in a Second-Growth Temperate Rainforest

by Steven A. Quick, Dylan G. Fischer and Michael J. Case

Forests 2024, 15(10), 1758; https://doi.org/10.3390/f15101758 - 6 Oct 2024

Viewed by 1632

Abstract

Forest restoration thinning may accelerate the development of structural complexity toward old-growth conditions faster than a natural forest, yet associated changes in forest carbon (C) are poorly understood. Old-growth forests are characterized by high levels of sequestered C in aboveground biomass and soil [...] Read more.

Forest restoration thinning may accelerate the development of structural complexity toward old-growth conditions faster than a natural forest, yet associated changes in forest carbon (C) are poorly understood. Old-growth forests are characterized by high levels of sequestered C in aboveground biomass and soil C pools, yet active management has well-recognized negative impacts on stored C. Effects of forest restoration thinning on forest C can be determined using longitudinal measurements and modeling based on stand conditions and tree growth. At Ellsworth Creek Preserve in Southwest Washington, forest restoration efforts in a second-growth temperate rainforest have been monitored using permanent plots since 2007. Here, we compare repeat measurements from 2020, modeled forest C, and measurements of O-horizon C pools from 2022 to determine C impacts of silvicultural treatments for old-growth restoration. We found good general agreement between empirical measurements and models of forest C using the Forest Vegetation Simulator (FVS). However, treatment alone was not a strong indicator for C conditions; rather, forest age and age–treatment interactions better predicted soil C responses to restoration treatments. These data may indicate that “light” forest restoration thinning can accelerate old-growth development with minimal effects on soil carbon—a win-win conservation strategy for old-growth forests and the climate. Full article

(This article belongs to the Section Forest Ecology and Management)

► Show Figures

Figure 1

11 pages, 988 KiB

Open AccessEditor’s ChoiceArticle

Total Polyphenol Content and Antioxidant Activity of Leaves and Fine Roots as Indicators of Drought Resistance in the Native Quercus robur and Alien Quercus rubra

by Tsvetana Masante, Sofia Cafà and Antonino Di Iorio

Forests 2024, 15(9), 1647; https://doi.org/10.3390/f15091647 - 18 Sep 2024

Viewed by 1406

Abstract

Research Highlights: Environmental abiotic stressors generate secondary stresses in plants, such as osmotic and oxidative stresses, which negatively influence their normal growth, development, and metabolism. Research about other non-enzymatic components with antioxidant capacity has recently focused on polyphenols. However, their role as indicators [...] Read more.

Research Highlights: Environmental abiotic stressors generate secondary stresses in plants, such as osmotic and oxidative stresses, which negatively influence their normal growth, development, and metabolism. Research about other non-enzymatic components with antioxidant capacity has recently focused on polyphenols. However, their role as indicators of drought and shade tolerance in woody species leaves and roots has been poorly explored or was limited to leaves only. Background and Objectives: Under a scenario of increasing drought, understanding the seedling responses in terms of total polyphenols and their antioxidant activity, in particular at the fine root system level, may help to elucidate the native–alien species interaction. Materials and Methods: At the beginning of July, 5-month-old native Quercus robur and alien Quercus rubra seedlings were transferred indoors to the growth chamber and subjected to progressive soil drying for 21 days. Results: The decrease in soil water content was more pronounced for Q. robur (9%) than for Q. rubra (34% of field capacity). Leaf water potential significantly decreased over time in Q. robur but did not differ from the control in Q. rubra. The total polyphenol concentration in Q. robur was markedly lower in the leaves and significantly higher in the fine roots than in Q. rubra. For the leaves, both species showed markedly higher values if well-watered, and the values significantly decreased in response to drought only in Q. rubra. In contrast, the fine root values for both species were markedly higher if droughted and decreased significantly in time only in Q. robur. Differently from the polyphenol concentration, the antioxidant capacity of Q. rubra was always higher in both the leaves and fine roots. Conclusions: The higher antioxidant activity of the alien species Q. rubra revealed by this work, combined with its isohydric behaviour, could further shed some light on our understanding of its competitive performance at the seedling stage against the native Q. robur. Full article

(This article belongs to the Special Issue Seedling Management in Temperate Forest Ecosystems)

► Show Figures

Figure 1

23 pages, 2911 KiB

Open AccessEditor’s ChoiceReview

Reduction and Reuse of Forestry and Agricultural Bio-Waste through Innovative Green Utilization Approaches: A Review

by Jianhui Guo, Yi Zhang, Jianjun Fang, Ziwei Ma, Cheng Li, Mengyao Yan, Naxin Qiao, Yang Liu and Mingming Bian

Forests 2024, 15(8), 1372; https://doi.org/10.3390/f15081372 - 6 Aug 2024

Cited by 4 | Viewed by 2508

Abstract

Biomass waste, which is biodegradable and vastly underutilized, is generated in huge quantities worldwide. Forestry and agricultural biomass wastes are notable for their wide availability, high yield, biodegradability, and recyclability. The accumulation of these wastes not only occupies valuable land but causes serious [...] Read more.

Biomass waste, which is biodegradable and vastly underutilized, is generated in huge quantities worldwide. Forestry and agricultural biomass wastes are notable for their wide availability, high yield, biodegradability, and recyclability. The accumulation of these wastes not only occupies valuable land but causes serious environmental pollution, which can ultimately harm human health. Therefore, leveraging scientific technology to convert forestry and agricultural bio-waste into bioenergy and other valuable products is crucial. In this paper, common forestry and agricultural bio-waste such as straw, rice husks, livestock manure, tree branches, sawdust, and bioenergy (bioethanol, biogas, biodiesel, biohydrogen) were selected as keywords, with the theme of green and efficient utilization. This paper provides a comprehensive review of the sources of biomass waste, existing recycling technologies, and the potential of forestry and agricultural bio-waste as material additives and for conversion to biomass energy and other derivatives, along with future recycling prospects. Full article

(This article belongs to the Special Issue Advances in the Sustainable Development and High-Value Utilization of Forestry Resources—2nd Edition)

► Show Figures

Figure 1

21 pages, 3594 KiB

Open AccessEditor’s ChoiceArticle

Different Responses of Terrestrial Carbon Fluxes to Environmental Changes in Cold Temperate Forest Ecosystems

by Mihang Jiang, Xinjie Liu and Liangyun Liu

Forests 2024, 15(8), 1340; https://doi.org/10.3390/f15081340 - 1 Aug 2024

Cited by 1 | Viewed by 1552

Abstract

As the largest carbon reservoir within terrestrial ecosystems, forest ecosystems play a major role as carbon sinks in the global carbon cycle. There are still some uncertainties regarding the responses of different carbon fluxes to environmental changes in cold temperate climate forest ecosystems. [...] Read more.

As the largest carbon reservoir within terrestrial ecosystems, forest ecosystems play a major role as carbon sinks in the global carbon cycle. There are still some uncertainties regarding the responses of different carbon fluxes to environmental changes in cold temperate climate forest ecosystems. Here, 14 cold temperate forest flux sites for at least ten years were investigated, including carbon fluxes and environmental variables such as temperature, precipitation, shortwave radiation, and vapor pressure deficit. By calculating the Spearman correlation coefficient, there was a congruence between photosynthetic productivity (i.e., gross primary productivity, GPP) and carbon sequestration (i.e., net ecosystem productivity, NEP) at thirteen forest sites, and at one forest site, GPP and NEP were decoupled. Annual GPP and NEP displayed a consistent trend when temperature and precipitation had significantly opposite trends and when temperature had a significantly positive correlation with VPD. But when VPD was significantly negatively correlated with both temperature and SW in spring and when temperature was negatively correlated with both SW and VPD in summer, a decoupling of GPP and NEP occurred. The impacts of various environmental factors on the annual carbon fluxes were calculated for each year and season using the path analysis method. At forest sites with consistent trends in GPP and NEP, annual, spring, and summer temperatures had significant positive correlations with GPP and ecosystem respiration (RE). While at the decoupled forest site, environmental factors had a stronger effect on RE, which then contributed to the observed decoupling of GPP and NEP. Finally, the Partial Least Squares method was used to analyze the relative contribution of each environmental factor to annual carbon fluxes. The results revealed that temperature and summer precipitation were the key environmental factors affecting forest ecosystems. This study provides important insights into the different responses of carbon fluxes in forest ecosystems undergoing environmental changes. Full article

(This article belongs to the Topic Forest Carbon Sequestration and Climate Change Mitigation)

► Show Figures

Figure 1

22 pages, 913 KiB

Open AccessEditor’s ChoiceReview

A Comparative Literature Review of Machine Learning and Image Processing Techniques Used for Scaling and Grading of Wood Logs

by Yohann Jacob Sandvik, Cecilia Marie Futsæther, Kristian Hovde Liland and Oliver Tomic

Forests 2024, 15(7), 1243; https://doi.org/10.3390/f15071243 - 17 Jul 2024

Cited by 1 | Viewed by 1823

Abstract

This literature review assesses the efficacy of image-processing techniques and machine-learning models in computer vision for wood log grading and scaling. Four searches were conducted in four scientific databases, yielding a total of 1288 results, which were narrowed down to 33 relevant studies. [...] Read more.

This literature review assesses the efficacy of image-processing techniques and machine-learning models in computer vision for wood log grading and scaling. Four searches were conducted in four scientific databases, yielding a total of 1288 results, which were narrowed down to 33 relevant studies. The studies were categorized according to their goals, including log end grading, log side grading, individual log scaling, log pile scaling, and log segmentation. The studies were compared based on the input used, choice of model, model performance, and level of autonomy. This review found a preference for images over point cloud representations for logs and an increase in camera use over laser scanners. It identified three primary model types: classical image-processing algorithms, deep learning models, and other machine learning models. However, comparing performance across studies proved challenging due to varying goals and metrics. Deep learning models showed better performance in the log pile scaling and log segmentation goal categories. Cameras were found to have become more popular over time compared to laser scanners, possibly due to stereovision cameras taking over for laser scanners for sampling point cloud datasets. Classical image-processing algorithms were consistently used, deep learning models gained prominence in 2018, and other machine learning models were used in studies published between 2010 and 2018. Full article

(This article belongs to the Special Issue Applications of Advanced Technologies for Improved Precision in Forest Operations)

► Show Figures

Figure 1

22 pages, 23895 KiB

Open AccessEditor’s ChoiceArticle

Analysis of Spatiotemporal Evolution and Driving Forces of Vegetation from 2001 to 2020: A Case Study of Shandong Province, China

by Dejin Dong, Ziliang Zhao, Hongdi Gao, Yufeng Zhou, Daohong Gong, Huaqiang Du and Yuichiro Fujioka

Forests 2024, 15(7), 1245; https://doi.org/10.3390/f15071245 - 17 Jul 2024

Cited by 2 | Viewed by 1841

Abstract

As global climate change intensifies and human activities escalate, changes in vegetation cover, an important ecological indicator, hold significant implications for ecosystem protection and management. Shandong Province, a critical agricultural and economic zone in China, experiences vegetation changes that crucially affect regional climate [...] Read more.

As global climate change intensifies and human activities escalate, changes in vegetation cover, an important ecological indicator, hold significant implications for ecosystem protection and management. Shandong Province, a critical agricultural and economic zone in China, experiences vegetation changes that crucially affect regional climate regulation and biodiversity conservation. This study employed normalized difference vegetation index (NDVI) data, combined with climatic, topographic, and anthropogenic activity data, utilizing trend analysis methods, partial correlation analysis, and Geodetector to comprehensively analyze the spatiotemporal variations and primary driving factors of vegetation cover in Shandong Province from 2001 to 2020. The findings indicate an overall upward trend in vegetation cover, particularly in areas with concentrated human activities. Climatic factors, such as precipitation and temperature, exhibit a positive correlation with vegetation growth, while land use changes emerge as one of the key drivers influencing vegetation dynamics. Additionally, topography also impacts the spatial distribution of vegetation to a certain extent. This research provides a scientific basis for ecological protection and land management in Shandong Province and similar regions, supporting the formulation of effective vegetation restoration and ecological conservation strategies. Full article

(This article belongs to the Special Issue Hydrologic and Carbon Balance Responses of Forests Resulting from Climate Change)

► Show Figures

Figure 1

21 pages, 3767 KiB

Open AccessEditor’s ChoiceArticle

Mapping Planted Forests in the Korean Peninsula Using Artificial Intelligence

by Ankita Mitra, Cesar Ivan Alvarez, Akane O. Abbasi, Nancy L. Harris, Guofan Shao, Bryan C. Pijanowski, Mohammad Reza Jahanshahi, Javier G. P. Gamarra, Hyun-Seok Kim, Tae-Kyung Kim, Daun Ryu and Jingjing Liang

Forests 2024, 15(7), 1216; https://doi.org/10.3390/f15071216 - 12 Jul 2024

Cited by 1 | Viewed by 1608

Abstract

Forests are essential for maintaining the ecological balance of the planet and providing critical ecosystem services. Amidst an increasing rate of global forest loss due to various natural and anthropogenic factors, many countries are committed to battling forest loss by planting new forests. [...] Read more.

Forests are essential for maintaining the ecological balance of the planet and providing critical ecosystem services. Amidst an increasing rate of global forest loss due to various natural and anthropogenic factors, many countries are committed to battling forest loss by planting new forests. Despite the reported national statistics on the land area in plantations, accurately delineating boundaries of planted forests with remotely sensed data remains a great challenge. In this study, we explored several deep learning approaches based on Convolutional Neural Networks (CNNs) for mapping the extent of planted forests in the Korean Peninsula. Our methodology involved data preprocessing, the application of data augmentation techniques, and rigorous model training, with performance assessed using various evaluation metrics. To ensure robust performance and accuracy, we validated the model’s predictions across the Korean Peninsula. Our analysis showed that the integration of the Near Infrared band from 10 m Sentinel-2 remote sensing images with the UNet deep learning model, incorporated with unfrozen ResNet-34 backbone architecture, produced the best model performance. With a recall of 64% and precision of 76.8%, the UNet model surpassed the other pixel-based deep learning models, including DeepLab and Pyramid Sense Parsing, in terms of classification accuracy. When compared to the ensemble-based Random Forest (RF) machine learning model, the RF approach demonstrates a significantly lower recall rate of 55.2% and greater precision of 92%. These findings highlight the unique strength of deep learning and machine learning approaches for mapping planted forests in diverse geographical regions on Earth. Full article

(This article belongs to the Special Issue Forest Species Distribution, Diversity and Growth under Climate Change)

► Show Figures

Figure 1

18 pages, 3419 KiB

Open AccessEditor’s ChoiceArticle

Geoforms and Biogeography Defining Mangrove Primary Productivity: A Meta-Analysis for the American Pacific

by Carolina Velázquez-Pérez, Emilio I. Romero-Berny, Clara Luz Miceli-Méndez, Patricia Moreno-Casasola and Sergio López

Forests 2024, 15(7), 1215; https://doi.org/10.3390/f15071215 - 12 Jul 2024

Cited by 1 | Viewed by 1626

Abstract

We present a meta-analysis of mangrove litterfall across 58 sites in the American Pacific, exploring its variability among geoforms, ecoregions, and provinces. This study contributes to filling the information gap on litter-based primary productivity in American mangroves at the ecoregional level and directly [...] Read more.

We present a meta-analysis of mangrove litterfall across 58 sites in the American Pacific, exploring its variability among geoforms, ecoregions, and provinces. This study contributes to filling the information gap on litter-based primary productivity in American mangroves at the ecoregional level and directly examines the effects of geomorphological and biogeographic factors on mangrove productivity. The objective was to evaluate how geoform, ecoregion, and province factors, along with eight environmental variables, influence litterfall-based primary productivity. Each site was categorized according to its landform through the analysis of satellite images obtained from various sensors on the Google Earth Pro v. 7.3.6 platform. Additionally, it was categorized according to its ecoregion and province by analyzing the occurrence of the sites on biogeographic unit coverage in ArcMap 10.4.1. We then analyzed the effect of each factor and the efficiency of categorization using multivariate methods. Our results showed significant differences in litterfall among the geoforms, with estuaries exhibiting higher litterfall production (11.90 Mg ha⁻¹ year⁻¹) compared to lagoons (7.49 ± 4.13 Mg ha⁻¹ year⁻¹). Differences were also observed among provinces, with the highest average in the Tropical Eastern Pacific (11.19 ± 3.63 Mg ha⁻¹ year⁻¹) and the lowest in the Warm Temperate Northeast Pacific (7.34 ± 4.28 Mg ha⁻¹ year⁻¹). Allocation success analyses indicated that sites classified by dominant species and province were more predictable (>60.34%) for litterfall production. Additionally, the maximum temperature and the precipitation of the wettest month and the driest month explained 34.13% of the variability in mangrove litter-based primary productivity. We conclude that mangrove litterfall production is influenced by coastal geomorphic characteristics and biogeography, which are, in turn, affected by latitude-induced climate variation. Full article

(This article belongs to the Special Issue Effect of Mangrove Ecosystems on Coastal Ecology and Climate Change)

► Show Figures

Figure 1

25 pages, 2065 KiB

Open AccessEditor’s ChoiceReview

Challenges and Prospects of Applying Nanocellulose for the Conservation of Wooden Cultural Heritage—A Review

by Paulina Kryg, Bartłomiej Mazela, Waldemar Perdoch and Magdalena Broda

Forests 2024, 15(7), 1174; https://doi.org/10.3390/f15071174 - 5 Jul 2024

Cited by 3 | Viewed by 1563

Abstract

Nanocellulose is a nanostructured form of cellulose, which retains valuable properties of cellulose such as renewability, biodegradability, biocompatibility, nontoxicity, and sustainability and, due to its nano-sizes, acquires several useful features, such as low density, high aspect ratio and stiffness, a high specific surface [...] Read more.

Nanocellulose is a nanostructured form of cellulose, which retains valuable properties of cellulose such as renewability, biodegradability, biocompatibility, nontoxicity, and sustainability and, due to its nano-sizes, acquires several useful features, such as low density, high aspect ratio and stiffness, a high specific surface area, easy processing and functionalisation, and good thermal stability. All these make it a highly versatile green nanomaterial for multiple applications, including the conservation of cultural heritage. This review provides the basic characteristics of all nanocellulose forms and their properties and presents the results of recent research on nanocellulose formulations applied for conserving historical artefacts made of wood and paper, discussing their effectiveness, advantages, and disadvantages. Pure nanocellulose proves particularly useful for conserving historical paper since it can form a durable, stable coating that consolidates the surface of a degraded object. However, it is not as effective for wood consolidation treatment due to its poor penetration into the wood structure. The research shows that this disadvantage can be overcome by various chemical modifications of the nanocellulose surface; owing to its specific chemistry, nanocellulose can be easily functionalised and, thus, enriched with the properties required for an effective wood consolidant. Moreover, combining nanocellulose with other agents can also improve its properties, adding new functionalities to the developed supramolecular systems that would address multiple needs of degraded artefacts. Since the broad use of nanocellulose in conservation practice depends on its properties, price, and availability, the development of new, effective, green, and industrial-scale production methods ensuring the manufacture of nanocellulose particles with standardised properties is necessary. Nanocellulose is an interesting and very promising solution for the conservation of cultural heritage artefacts made of paper and wood; however, further thorough interdisciplinary research is still necessary to devise new green methods of its production as well as develop new effective and sustainable nanocellulose-based conservation agents, which would replace synthetic, non-sustainable consolidants and enable proper conservation of historical objects of our cultural heritage. Full article

(This article belongs to the Special Issue Wood as Cultural Heritage Material: 2nd Edition)

► Show Figures

Graphical abstract

21 pages, 4014 KiB

Open AccessEditor’s ChoiceArticle

Soil Microbial Communities Responses to Multiple Generations’ Successive Planting of Eucalyptus Trees

by Chenyang Jiang, Yaqin He, Yuhong Cui, Yahui Lan, Han Zhang and Shaoming Ye

Forests 2024, 15(7), 1166; https://doi.org/10.3390/f15071166 - 4 Jul 2024

Viewed by 1254

Abstract

The impacts of the successive planting of Eucalyptus on soil microbial communities and their underlying mechanisms remain unknown, limiting our understanding of its long-term effects on soil ecosystems. This study examined the 0–20 cm and 20–40 cm soil layers, investigating changes in soil [...] Read more.

The impacts of the successive planting of Eucalyptus on soil microbial communities and their underlying mechanisms remain unknown, limiting our understanding of its long-term effects on soil ecosystems. This study examined the 0–20 cm and 20–40 cm soil layers, investigating changes in soil bacterial and fungal communities after multiple plantings of Eucalyptus grandis × urophylla using high-throughput sequencing. Furthermore, we used the structural equation model (SEM) to analyze the relationships among soil active organic carbon (SAOC), enzyme activity, and microbial diversity. The study showed that the multigeneration successive planting of Eucalyptus significantly increased the soil bulk density and decreased the soil physicochemical properties and soil enzyme activities (p < 0.05). The soil’s dominant microbial compositions were unchanged in the two soil horizons, but the relative abundances of some dominant phyla (e.g., Crenarchaeota, Basidiomycota and Actinobacteriota) were affected by successive planting. The variability in the microbial community structure was influenced primarily by the soil water content (SWC) and organic carbon (p < 0.05). The microbial community diversity in the 20–40 cm horizon was significantly affected by multigeneration succession (p < 0.05). SWC was the core factor driving microbial community diversity. SEM results showed that multigeneration successive planting obviously limits SAOC fractions and enzyme activities, negatively affecting soil microbial diversity. Our study highlights the impact of the multigeneration successive planting of Eucalyptus on soil microbial community structure and suggests adjustments in forestry practices to mitigate soil degradation. Full article

(This article belongs to the Section Forest Soil)

► Show Figures

Figure 1

20 pages, 2768 KiB

Open AccessEditor’s ChoiceArticle

Climate as a Driver of Aboveground Biomass Density Variation: A Study of Ten Pine Species in Mexico

by Dioseline Girón-Gutiérrez, Jorge Méndez-González, Tamara G. Osorno-Sánchez, Julián Cerano-Paredes, José C. Soto-Correa and Víctor H. Cambrón-Sandoval

Forests 2024, 15(7), 1160; https://doi.org/10.3390/f15071160 - 3 Jul 2024

Cited by 1 | Viewed by 1422

Abstract

The native pine species of Mexico, constituting 55% of all pine species, play a crucial economic role for local populations. Climatic factors affected by climate change, such as temperature and precipitation, influence tree physiology and distribution. Our study focused on the aboveground biomass [...] Read more.

The native pine species of Mexico, constituting 55% of all pine species, play a crucial economic role for local populations. Climatic factors affected by climate change, such as temperature and precipitation, influence tree physiology and distribution. Our study focused on the aboveground biomass density (AGB_d) distribution of ten Mexican pine species and its correlation with bioclimatic variables. Dendrometric data were obtained from National Forest and Soil Inventory (INFyS) (period: 2009 and 2014) while data on bioclimatic variables were obtained from WorldClim2. AGB_d distribution maps were generated for the ten species. Spearman and Bayesian correlations were determined between AGB_d and the 19 bioclimatic variables. Six species showed a significant correlation (p < 0.05) between AGB_d and bioclimatic variables. The results did not show geographical regionalization for AGB_d and highlighted the complexity of responses in each species. Temperature variables showed the highest number of correlations with AGB_d (76%), which varied between species. Regarding precipitation, correlations were mostly positive. In general, our findings suggest an important link between climate and AGB_d, from which relevant strategies can be developed for sustainable forest management of the country’s forests in relation to expected climate change. Full article

(This article belongs to the Section Forest Meteorology and Climate Change)

► Show Figures

Figure 1

21 pages, 5988 KiB

Open AccessEditor’s ChoiceArticle

Use of a Consumer-Grade UAV Laser Scanner to Identify Trees and Estimate Key Tree Attributes across a Point Density Range

by Michael S. Watt, Sadeepa Jayathunga, Robin J. L. Hartley, Grant D. Pearse, Peter D. Massam, David Cajes, Benjamin S. C. Steer and Honey Jane C. Estarija

Forests 2024, 15(6), 899; https://doi.org/10.3390/f15060899 - 22 May 2024

Cited by 2 | Viewed by 1814

Abstract

The management of plantation forests using precision forestry requires advanced inventory methods. Unmanned aerial vehicle laser scanning (ULS) offers a cost-effective approach to accurately estimate forest structural attributes at both plot and individual tree levels. We examined the utility of ULS data collected [...] Read more.

The management of plantation forests using precision forestry requires advanced inventory methods. Unmanned aerial vehicle laser scanning (ULS) offers a cost-effective approach to accurately estimate forest structural attributes at both plot and individual tree levels. We examined the utility of ULS data collected from a radiata pine stand for tree detection and prediction of diameter at breast height (DBH) and stem volume, using data thinned to 13-point densities (ranging from 10–12,200 points/m²). These datasets were created using a DTM with the highest pulse density and DTMs that used the native decimated point clouds. Models of DBH were constructed using partial least squares (PLS) and random forest (RF) from seven classes of metrics that characterized the horizontal and vertical structure of the canopy. Individual tree segmentation was consistently accurate across the 13-point densities and was insensitive to DTM type (F1 scores > 0.96). Predictions of DBH using PLS models were consistently more accurate than RF models and accuracy was insensitive to the DTM type. Using data from the native DTMs, DBH estimation using PLS had the lowest RMSE of 1.624 cm (R² of 0.756) at a point density of 12,200 points/m². Stem volume predictions made using PLS predictions of DBH and height from the ULS had the lowest RMSE of 0.0418 m³ (R² of 0.792) at 12,200 points/m². The RMSE values for DBH and volume remained relatively stable from 12,200 to between 750 and 400 points/m², with reductions in accuracy occurring as point density declined below this threshold. Overall, these findings have significant implications, particularly for the precise estimation of DBH and stem volume at the individual tree level. They demonstrate the potential of cost-effective ULS sensors for rapid and frequent plantation forest assessment, thereby enhancing the application of light detection and ranging (LiDAR) technology in plantation forest management. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

► Show Figures

Figure 1

31 pages, 3007 KiB

Open AccessEditor’s ChoiceReview

Estimating Economic and Livelihood Values of the World’s Largest Mangrove Forest (Sundarbans): A Meta-Analysis

by Akbar Hossain Kanan, Mauro Masiero and Francesco Pirotti

Forests 2024, 15(5), 837; https://doi.org/10.3390/f15050837 - 10 May 2024

Cited by 2 | Viewed by 2163

Abstract

We explored the state of the art economic and livelihood valuation of ecosystem services (ES) in the Sundarbans mangroves, including a comparative analysis between the Bangladesh and Indian parts of the region. We identified 145 values from 26 studies to estimate the Sundarbans’ [...] Read more.

We explored the state of the art economic and livelihood valuation of ecosystem services (ES) in the Sundarbans mangroves, including a comparative analysis between the Bangladesh and Indian parts of the region. We identified 145 values from 26 studies to estimate the Sundarbans’ economic and livelihood values. The number of ES valuation studies of the Sundarbans is scant, and it has gradually increased over time, focusing mainly on the estimation of provisioning ES (66.2%), followed by regulating and maintenance (25.5%), and cultural (8.3%) ES. However, recently, attention has been paid to estimation, regulating and maintenance, and cultural ES. The number of studies on ES was higher for the Bangladesh (73%) part of the Sundarbans than the Indian (27%) one. The estimated economic values of the Sundarbans’ provisioning, regulating and maintenance, and cultural ES were US $ 713.30 ha⁻¹ yr⁻¹, US $ 2584.46 ha⁻¹ yr⁻¹, and US $ 151.88 ha⁻¹ yr⁻¹, respectively. Except for cultural ES, the identified values for the other two ES categories were about 1.5 to 2.5 times higher for the Bangladesh Sundarbans compared to the Indian ones. The results of the meta-regression model showed that the estimated economic and livelihood values of ES are affected by the associated variables (e.g., type of ES, valuation methods, study area, population, and GDP). Our study also identified some remarkable gaps and limitations in the economic and livelihood valuation of the ES of the Sundarbans, highlighting the need for further research to find out the values of all ES to help with policy decision-making. Full article

(This article belongs to the Special Issue Economic Valuation of Forest Resources)

► Show Figures

Figure 1

16 pages, 3633 KiB

Open AccessEditor’s ChoiceArticle

Dynamic Height Growth Equations and Site Index-Based Biomass Models for Young Native Species Afforestations in Spain

by Rafael Calama, Guillermo Madrigal, Miren del Río, Eduardo López-Senespleda, Marta Pardos, Ricardo Ruiz-Peinado and María Menéndez-Miguélez

Forests 2024, 15(5), 827; https://doi.org/10.3390/f15050827 - 8 May 2024

Cited by 1 | Viewed by 1590

Abstract

The expansion of forested areas through afforestation and reforestation is widely recognized as a highly effective natural solution for mitigating climate change. Accurately assessing the potential carbon uptake capacity of newly afforested areas requires modelling tools to estimate biomass stocks, including site index [...] Read more.

The expansion of forested areas through afforestation and reforestation is widely recognized as a highly effective natural solution for mitigating climate change. Accurately assessing the potential carbon uptake capacity of newly afforested areas requires modelling tools to estimate biomass stocks, including site index curves and biomass models. Given the unique conditions in terms of tree size, uniform spacing, and tree allometries observed in young afforestations compared to natural stands, specific tools are necessary. In Spain, over 800,000 ha has been afforested with native forest species since 1992, but specific modelling tools for these plantations are lacking. Using data from 370 stem analyses collected across an extensive network of plots in young afforestations, we developed dynamic height growth and site index models for the main native species (five pines and five oaks) commonly used in afforestation in Spain. We compared various nonlinear models, such as ADA (algebraic difference approach) and GADA (generalized algebraic difference approach) expansions. The developed site index models were then used to predict the total biomass stored in the afforestation. Our results underscore the necessity for specific site index models tailored to afforestations, as well as the potential of the established site index in predicting biomass and carbon fixation capacity in these young forests. Full article

(This article belongs to the Special Issue Forest Growth Modeling in Different Ecological Conditions)

► Show Figures

Figure 1

23 pages, 4793 KiB

Open AccessEditor’s ChoiceArticle

Temporal Dynamics of Canopy Properties and Carbon and Water Fluxes in a Temperate Evergreen Angiosperm Forest

by Alexandre A. Renchon, Vanessa Haverd, Cathy M. Trudinger, Belinda E. Medlyn, Anne Griebel, Daniel Metzen, Jürgen Knauer, Matthias M. Boer and Elise Pendall

Forests 2024, 15(5), 801; https://doi.org/10.3390/f15050801 - 30 Apr 2024

Cited by 1 | Viewed by 1681

Abstract

The forest–atmosphere exchange of carbon and water is regulated by meteorological conditions as well as canopy properties such as leaf area index (LAI, m² m⁻²), photosynthetic capacity (PC μmol m⁻² s⁻¹), or surface conductance in optimal conditions [...] Read more.

The forest–atmosphere exchange of carbon and water is regulated by meteorological conditions as well as canopy properties such as leaf area index (LAI, m² m⁻²), photosynthetic capacity (PC μmol m⁻² s⁻¹), or surface conductance in optimal conditions (G_s,opt, mmol m⁻² s⁻¹), which can vary seasonally and inter-annually. This variability is well understood for deciduous species but is poorly characterized in evergreen forests. Here, we quantify the seasonal dynamics of a temperate evergreen eucalypt forest with estimates of LAI, litterfall, carbon and water fluxes, and meteorological conditions from measurements and model simulations. We merged MODIS Enhanced Vegetation Index (EVI) values with site-based LAI measurements to establish a 17-year sequence of monthly LAI. We ran the Community Atmosphere Biosphere Land Exchange model (CABLE-POP (version r5046)) with constant and varying LAI for our site to quantify the influence of seasonal canopy dynamics on carbon and water fluxes. We observed that the peak of LAI occurred in late summer–early autumn, with a higher and earlier peak occurring in years when summer rainfall was greater. Seasonality in litterfall and allocation of net primary productivity (F_NPP) to leaf growth (a_f, 0–1) drove this pattern, suggesting a complete renewal of the canopy before the timing of peak LAI. Litterfall peaked in spring, followed by a high a_f in summer, at the end of which LAI peaked, and PC and G_s,opt reached their maximum values in autumn, resulting from a combination of high LAI and efficient mature leaves. These canopy dynamics helped explain observations of maximum gross ecosystem production (F_GEP) in spring and autumn and net ecosystem carbon loss in summer at our site. Inter-annual variability in LAI was positively correlated with Net Ecosystem Production (F_NEP). It would be valuable to apply a similar approach to other temperate evergreen forests to identify broad patterns of seasonality in leaf growth and turnover. Because incorporating dynamic LAI was insufficient to fully capture the dynamics of F_GEP, observations of seasonal variation in photosynthetic capacity, such as from solar-induced fluorescence, should be incorporated in land surface models to improve ecosystem flux estimates in evergreen forests. Full article

(This article belongs to the Section Forest Meteorology and Climate Change)

► Show Figures

Figure 1

16 pages, 4343 KiB

Open AccessEditor’s ChoiceArticle

Physical and Mechanical Properties of Fiberboard Made of MDF Residues and Phase Change Materials

by Gustavo E. Rodríguez, Cecilia Bustos Ávila and Alain Cloutier

Forests 2024, 15(5), 802; https://doi.org/10.3390/f15050802 - 30 Apr 2024

Cited by 1 | Viewed by 2422

Abstract

The wood-based panel industry is experiencing an excessive accumulation of solid residues from the production of medium-density fiberboard (MDF) panels and moldings. It is possible to create new MDF products with acceptable physical and mechanical properties by revaluing MDF residues. Additionally, those products’ [...] Read more.

The wood-based panel industry is experiencing an excessive accumulation of solid residues from the production of medium-density fiberboard (MDF) panels and moldings. It is possible to create new MDF products with acceptable physical and mechanical properties by revaluing MDF residues. Additionally, those products’ thermal properties can be improved by incorporating phase change materials (PCMs). This study aims to develop a wood-based fiberboard made of MDF residues, capable of storing thermal energy. Two types of PCMs (liquid and microencapsulated), two PCM ratios (2% and 6%), and two types of adhesives (urea-formaldehyde and phenol-formaldehyde) were used to produce eight different types of panels. The vertical density profile, thickness swelling, water absorption, internal bond (IB), and static bending properties—modulus of elasticity (MOE) and modulus of rupture (MOR)—were determined for each panel type. The specific heat of the panels was also determined. The results show the panels’ densities were greater than 700 kg/m³. Thickness swelling in water improved by 23% compared to the reference value of the control panel PCMs after PCM incorporation. The highest IB value was 1.30 MPa, which is almost three times the minimum required by regulation standards. The incorporation of PCMs reduced the panels’ bending properties compared to the properties of the control panels. Even though the values obtained are sufficient to comply with the minimum values set out in ANSI standard A208.2 with an MOE value of 2072.4 MPa and the values obtained are sufficient to comply with the minimum standards with an MOE value of 2072.4 MPa and an MOR value of 16.4 MPa, when microencapsulated PCM is used, the specific heat of the panels is increased by more than 100% over that of the control panels. This study developed fiberboards with adequate physical and mechanical properties and capable of storing thermal energy. Full article

(This article belongs to the Special Issue Sustainable Materials in the Forest Products Industry)

► Show Figures

Figure 1

20 pages, 3216 KiB

Open AccessEditor’s ChoiceArticle

Riparian Forests as Nature-Based Solutions within the Mediterranean Context: A Biophysical and Economic Assessment for the Koiliaris River Watershed (Crete, Greece)

by Mauro Masiero, Giorgia Bottaro, Caterina Righetti, Nikolaos P. Nikolaidis, Maria A. Lilli and Davide Pettenella

Forests 2024, 15(5), 760; https://doi.org/10.3390/f15050760 - 26 Apr 2024

Cited by 3 | Viewed by 1755

Abstract

The Mediterranean Basin is severely impacted by anthropogenic changes affecting both natural ecosystems and human livelihoods. The region is highly vulnerable to natural hazards, with floods being considered the most important, due both to their frequency and impacts. Koiliaris watershed (northwest of Crete [...] Read more.

The Mediterranean Basin is severely impacted by anthropogenic changes affecting both natural ecosystems and human livelihoods. The region is highly vulnerable to natural hazards, with floods being considered the most important, due both to their frequency and impacts. Koiliaris watershed (northwest of Crete Island, Greece) represents a relevant case study as past land-use changes via deforestation and intense cultivation practices induce soil organic matter losses, making soils susceptible to water erosion and desertification. The restoration of native riparian forests has been identified as the most effective nature-based solution (NBS) for the area. Through modeling, our study assessed the effectiveness of this NBS in addressing flood risk and erosion while providing additional ecosystem services (carbon sequestration and biodiversity conservation). A cost–benefit analysis has been then implemented to also investigate the sustainability of the investment from an economic point of view. Our results show the NBS would be successful in ensuring a better flow of targeted ecosystem services compared to the business-as-usual conditions. The associated investment would result in economic sustainability and associated costs would be paid back in five years. Though site-specific, our study provides lessons learned for dealing with future land-restoration challenges in the Mediterranean to cope with climate change-related challenges. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

► Show Figures

Figure 1

21 pages, 5117 KiB

Open AccessEditor’s ChoiceArticle

Monitoring Forest Dynamics and Conducting Restoration Assessment Using Multi-Source Earth Observation Data in Northern Andes, Colombia

by Carlos Pedraza, Nicola Clerici, Marcelo Villa, Milton Romero, Adriana Sarmiento Dueñas, Dallan Beltrán Rojas, Paola Quintero, Mauricio Martínez and Josef Kellndorfer

Forests 2024, 15(5), 754; https://doi.org/10.3390/f15050754 - 25 Apr 2024

Viewed by 2775

Abstract

Examining the efficacy of current assessment methodologies for forest conservation and restoration initiatives to align with global and national agendas to combat deforestation and facilitate restoration efforts is necessary to identify efficient and robust approaches. The objective of this study is to understand [...] Read more.

Examining the efficacy of current assessment methodologies for forest conservation and restoration initiatives to align with global and national agendas to combat deforestation and facilitate restoration efforts is necessary to identify efficient and robust approaches. The objective of this study is to understand forest dynamics (1996–2021) and assess restoration implementations at the Urra’s supplying basin hydroelectric reservoir in Colombia. The processing approach integrates optical and radar Earth Observation (EO) data from Sentinel-2 and Landsat for forest mapping and multi-temporal forest change assessment (1996–2021), and a Sentinel-1 backscatter time-series analysis is conducted to assess the state of forest restoration implementations. The processing chain was scaled in a cloud-based environment using the Nebari and SEPPO software and the Python language. The results demonstrate an overall substantial decrease in forested areas in the 1996–2000 period (37,763 ha). An accuracy assessment of multi-temporal forest change maps showed a high precision in detecting deforestation events, while improvements are necessary for accurately representing non-forested areas. The forest restoration assessment suggests that the majority of the 270 evaluated plots are in the intermediate growth state (82.96%) compared to the reference data. This study underscores the need for robust and continuous monitoring systems that integrate ground truth data with EO techniques for enhanced accuracy and effectiveness in forest restoration and conservation endeavors. Full article

(This article belongs to the Special Issue Advances in Remote Sensing for Forestry: Theory, Methods, Applications, and Validation)

► Show Figures

Figure 1

16 pages, 2230 KiB

Open AccessEditor’s ChoiceArticle

Drought Impact on Eco-Physiological Responses and Growth Performance of Healthy and Declining Pinus sylvestris L. Trees Growing in a Dry Area of Southern Poland

by Barbara Benisiewicz, Sławomira Pawełczyk, Francesco Niccoli, Jerzy Piotr Kabala and Giovanna Battipaglia

Forests 2024, 15(5), 741; https://doi.org/10.3390/f15050741 - 24 Apr 2024

Cited by 3 | Viewed by 1958

Abstract

In recent years, several drought events hit Poland, affecting its forests. In Opole, Poland, tons of Pinus sylvestris L. deadwood is removed every year due to drought. Understanding the physiological mechanisms underlying tree vulnerability to drought, and tree responses, is important to develop [...] Read more.

In recent years, several drought events hit Poland, affecting its forests. In Opole, Poland, tons of Pinus sylvestris L. deadwood is removed every year due to drought. Understanding the physiological mechanisms underlying tree vulnerability to drought, and tree responses, is important to develop forest management strategies to face the ongoing climate change. This research provides comprehensive local-scale analyses of the sensitivity of healthy and declining trees to drought. We used dendrochronology and stable isotope analysis to compare five healthy and five declining trees. The analysis focused particularly on comparisons of basal area increment (BAI), δ¹³C, and intrinsic water-use efficiency (iWUE), as well as tree resistance, resilience, and recovery in response to drought events and sensitivity to selected meteorological parameters. We observed a significant reduction in BAI values in declining trees after 2000. Fifteen years later, the reduction was also visible in the iWUE values of these trees. Despite similar δ¹³C chronology patterns, declining trees showed higher δ¹³C correlations with meteorological parameters. We have shown that dendrochronology enables early detection of poor forest health conditions. Differences in iWUE chronologies occurring in recent years suggest that trees of both groups have chosen different adaptive strategies to cope with drought stress. Full article

(This article belongs to the Section Forest Ecophysiology and Biology)

► Show Figures

Figure 1

18 pages, 6380 KiB

Open AccessEditor’s ChoiceArticle

Wood Basic Density in Large Trees: Impacts on Biomass Estimates in the Southwestern Brazilian Amazon

by Flora Magdaline Benitez Romero, Thais de Nazaré Oliveira Novais, Laércio Antônio Gonçalves Jacovine, Eronildo Braga Bezerra, Rosana Barbosa de Castro Lopes, Juliana Sousa de Holanda, Edi Flores Reyna and Philip Martin Fearnside

Forests 2024, 15(5), 734; https://doi.org/10.3390/f15050734 - 23 Apr 2024

Cited by 1 | Viewed by 2580

Abstract

Wood basic density (WD) plays a crucial role in estimating forest biomass; moreover, improving wood-density estimates is needed to reduce uncertainties in the estimates of tropical forest biomass and carbon stocks. Understanding variations in this density along the tree trunk and its impact [...] Read more.

Wood basic density (WD) plays a crucial role in estimating forest biomass; moreover, improving wood-density estimates is needed to reduce uncertainties in the estimates of tropical forest biomass and carbon stocks. Understanding variations in this density along the tree trunk and its impact on biomass estimates is underexplored in the literature. In this study, the vertical variability of WD was assessed along the stems of large trees that had a diameter at breast height (DBH) ≥ 50 cm from a dense ombrophilous forest on terra firme (unflooded uplands) in Acre, Brazil. A total of 224 trees were sampled, including 20 species, classified by wood type. The average WD along the stem was determined by the ratio of oven-dry mass to saturated volume. Five models were tested, including linear and nonlinear ones, to fit equations for WD, selecting the best model. The variation among species was notable, ranging from 0.288 g cm⁻³ (Ceiba pentandra, L., Gaertn) to 0.825 g cm⁻³ (Handroanthus serratifolius, Vahl., S. Grose), with an average of 0.560 g cm⁻³ (±0.164, standard deviation). Significant variation was observed among individuals, such as in Schizolobium parahyba var. amazonicum (H. ex D.), which ranged from 0.305 to 0.655 g cm⁻³. WD was classified as low (≤0.40 g cm⁻³), medium (0.41–0.60 g cm⁻³), and high (≥0.61 g cm⁻³). The variability in WD along the stem differs by wood type. In trees with low-density wood, density shows irregular variation but tends to increase along the stem, whereas it decreases in species with medium- and high-density wood. The variation in WD along the stem can lead to underestimations or overestimations, not only in individual trees and species but also in total stocks when estimating forest biomass. Not considering this systematic bias results in significant errors, especially in extrapolations to vast areas, such as the Amazon. Full article

(This article belongs to the Section Forest Ecology and Management)

► Show Figures

Graphical abstract

12 pages, 1963 KiB

Open AccessEditor’s ChoiceArticle

The Nitrogen Cycle of a Cool-Temperate Deciduous Broad-Leaved Forest

by Ruoming Cao, Siyu Chen, Shinpei Yoshitake, Takeo Onishi, Yasuo Iimura and Toshiyuki Ohtsuka

Forests 2024, 15(4), 725; https://doi.org/10.3390/f15040725 - 21 Apr 2024

Cited by 1 | Viewed by 1449

Abstract

The nitrogen (N) cycle, a major biogeochemical cycle in forest ecosystems, notably affects ecosystem multifunctionality. However, the magnitude and role of organic N and the snow season remain uncertain in this cycle. We assessed the N flux and pool data of a temperate [...] Read more.

The nitrogen (N) cycle, a major biogeochemical cycle in forest ecosystems, notably affects ecosystem multifunctionality. However, the magnitude and role of organic N and the snow season remain uncertain in this cycle. We assessed the N flux and pool data of a temperate deciduous broad-leaved forest to clarify N cycle processes. The results showed that the most important component of the N pool was the soil N pool. The N demand of the site amounted to 139.4 kg N ha⁻¹ year⁻¹ and was divided into tree production (83.8%) and bamboo production (16.2%). We clarified that retranslocation (37.4%), mineralization at a soil depth of 0–5 cm (15.3%), litter leachate (4.6%), throughfall (2.3%), and canopy uptake (0.5%) provided 60.1% of the N demand. In terms of soil at 0–5 cm in depth, the net mineralization rate during the snow season contributed to 30% of the annual mineralization. We concluded that the study site was not N-saturated as a result of a positive N input–output flux budget. More than half of the total N was accounted for by dissolved organic N flowing through several pathways, indicating that organic N plays a vital role in the cycle. The mineralization rate in the soil layer during the snow season is an important link in the N cycle. Full article

(This article belongs to the Section Forest Ecophysiology and Biology)

► Show Figures

Figure 1

21 pages, 10278 KiB

Open AccessEditor’s ChoiceArticle

Due Diligence for Deforestation-Free Supply Chains with Copernicus Sentinel-2 Imagery and Machine Learning

by Ivan Reading, Konstantina Bika, Toby Drakesmith, Chris McNeill, Sarah Cheesbrough, Justin Byrne and Heiko Balzter

Forests 2024, 15(4), 617; https://doi.org/10.3390/f15040617 - 28 Mar 2024

Viewed by 2168

Abstract

At COP26, the Glasgow Leaders Declaration committed to ending deforestation by 2030. Implementing deforestation-free supply chains is of growing importance to importers and exporters but challenging due to the complexity of supply chains for agricultural commodities which are driving tropical deforestation. Monitoring tools [...] Read more.

At COP26, the Glasgow Leaders Declaration committed to ending deforestation by 2030. Implementing deforestation-free supply chains is of growing importance to importers and exporters but challenging due to the complexity of supply chains for agricultural commodities which are driving tropical deforestation. Monitoring tools are needed that alert companies of forest losses around their source farms. ForestMind has developed compliance monitoring tools for deforestation-free supply chains. The system delivers reports to companies based on automated satellite image analysis of forest loss around farms. We describe an algorithm based on the Python for Earth Observation (PyEO) package to deliver near-real-time forest alerts from Sentinel-2 imagery and machine learning. A Forest Analyst interprets the multi-layer raster analyst report and creates company reports for monitoring supply chains. We conclude that the ForestMind extension of PyEO with its hybrid change detection from a random forest model and NDVI differencing produces actionable farm-scale reports in support of the EU Deforestation Regulation. The user accuracy of the random forest model was 96.5% in Guatemala and 93.5% in Brazil. The system provides operational insights into forest loss around source farms in countries from which commodities are imported. Full article

(This article belongs to the Special Issue Application of Remote Sensing in Vegetation Dynamic and Ecology)

► Show Figures

Graphical abstract

46 pages, 5413 KiB

Open AccessEditor’s ChoiceSystematic Review

Nature-Based Tourism in National and Natural Parks in Europe: A Systematic Review

by Delia S. Donici and Diana E. Dumitras

Forests 2024, 15(4), 588; https://doi.org/10.3390/f15040588 - 24 Mar 2024

Cited by 3 | Viewed by 3820

Abstract

Considered among the fastest-growing industries in the world, tourism brings immense benefits but also creates certain challenges. Conservation of natural resources is a stringent necessity, without which the extraordinary ecosystems’ attributes that create the premises for nature-based tourism would reduce, alter, and subsequently [...] Read more.

Considered among the fastest-growing industries in the world, tourism brings immense benefits but also creates certain challenges. Conservation of natural resources is a stringent necessity, without which the extraordinary ecosystems’ attributes that create the premises for nature-based tourism would reduce, alter, and subsequently disappear. The aim of the present review is twofold: gaining a general understanding of what nature-based tourism is and providing a systematic literature review of articles on nature-based tourism in European national and natural parks, with emphasis on their applicability. The articles included in the present review were selected based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The review accounts for research conducted between 2000 and 2021 and is divided into two sections: articles aimed at understanding tourists’ behaviour and articles that are focused on other stakeholders or have the local communities in the foreground. While many studies are aimed at understanding tourists’ behaviour as a means of improving parks’ management, participatory strategies including local communities are often indicated as beneficial. The results of this paper can facilitate future research in the field and provide valuable knowledge to policymakers and any interested parties. Full article

(This article belongs to the Special Issue Changes in the Value of Forest Resources: Impacts of Human Activities)

► Show Figures

Figure 1

27 pages, 4660 KiB

Open AccessEditor’s ChoiceReview

Unearthing Current Knowledge Gaps in Our Understanding of Tree Stability: Review and Bibliometric Analysis

by Emmanuel Chukwudi Ekeoma, Mark Sterling, Nicole Metje, John Spink, Niall Farrelly and Owen Fenton

Forests 2024, 15(3), 513; https://doi.org/10.3390/f15030513 - 9 Mar 2024

Cited by 2 | Viewed by 2424

Abstract

Forest preservation and management are paramount for sustainable mitigation of climate change, timber production, and the economy. However, the potential of trees and forests to provide these benefits to the ecosystem is hampered by natural phenomena such as windthrow and anthropogenic activities. The [...] Read more.

Forest preservation and management are paramount for sustainable mitigation of climate change, timber production, and the economy. However, the potential of trees and forests to provide these benefits to the ecosystem is hampered by natural phenomena such as windthrow and anthropogenic activities. The aim of the current research was to undertake a critical thematic review (from 1983 to 2023) informed by a bibliometric analysis of existing literature on tree stability. The results revealed an increase in tree stability research between 2019 and 2022, with the USA, France, and Italy leading in research output, while Scotland and England notably demonstrated high research influence despite fewer publications. A keyword analysis showed that tree stability can be divided into four themes: tree species, architecture, anchorage, and environmental factors. Prominent studies on tree stability have focused on root anchorage. However, more recently, there has been a growing emphasis on urban forestry and disease-induced tree damage, underscoring a shift towards climate change and diversity research. It was concluded that considerable knowledge gaps still exist; that greater geographic diversification of research is needed and should include tropical and sub-tropical regions; that research relating to a wider range of soil types (and textures) should be conducted; and that a greater emphasis on large-scale physical modelling is required. Data and knowledge produced from these areas will improve our collective understanding of tree stability and therefore help decision makers and practitioners manage forestry resources in a more sustainable way into the future. Full article

(This article belongs to the Section Forest Ecology and Management)

► Show Figures

Figure 1

17 pages, 1106 KiB

Open AccessEditor’s ChoiceArticle

Economic Profitability of Carbon Sequestration of Fine-Aroma Cacao Agroforestry Systems in Amazonas, Peru

by Malluri Goñas, Nilton B. Rojas-Briceño, Darwin Gómez Fernández, Daniel Iliquín Trigoso, Nilton Atalaya Marin, Verónica Cajas Bravo, Jorge R. Díaz-Valderrama, Jorge L. Maicelo-Quintana and Manuel Oliva-Cruz

Forests 2024, 15(3), 500; https://doi.org/10.3390/f15030500 - 8 Mar 2024

Viewed by 2443

Abstract

Currently, the economic profitability of cocoa is being affected by the increasing incidence of pests, low selling prices, high production costs, and the presence of cadmium in cocoa farms, posing a potential risk of crop abandonment. Therefore, the objective of the present research [...] Read more.

Currently, the economic profitability of cocoa is being affected by the increasing incidence of pests, low selling prices, high production costs, and the presence of cadmium in cocoa farms, posing a potential risk of crop abandonment. Therefore, the objective of the present research was to evaluate the economic profitability of carbon sequestration of fine-aroma cacao agroforestry systems in Amazonas, Peru, using the economic indicators of NPV, EIRR, and the benefit–cost ratio. For this purpose, 53 small cocoa producers of the APROCAM cooperative were involved, from which data were obtained on the general characteristics of the production system, production and maintenance costs, indirect costs, and administrative costs; in addition, the costs of implementation and maintenance of an environmental services project were calculated to finally make a cash flow projected over 5 years. As part of the results, the economic analysis was carried out on 104.25 hectares of cocoa belonging to the total number of farmers evaluated, who reported an average yield of 957.32 kg of dry cocoa per he. In addition, it was found that the production cost is PEN 3.91/kg of dry cocoa, and the average selling price is PEN 7.38/kg of dry cocoa. After the economic analysis, it was found that the implementation of an environmental services project is profitable (NPV = PEN 1,454,547.8; EIRR = 44% and B/C = 1.86). These results open up an opportunity for cocoa farmers to diversify and increase their income by contributing to climate change mitigation. Full article

(This article belongs to the Special Issue Impacts of Forest Management Practices on Carbon Sequestration and Greenhouse Gas Exchange)

► Show Figures

Figure 1

15 pages, 5015 KiB

Open AccessEditor’s ChoiceArticle

Characterization of Change in Tree Cover State and Condition over the Conterminous United States

by Francis K. Dwomoh and Roger F. Auch

Forests 2024, 15(3), 470; https://doi.org/10.3390/f15030470 - 2 Mar 2024

Cited by 1 | Viewed by 1777

Abstract

Variability in the effects of disturbances and extreme climate events can lead to changes in tree cover over time, including partial or complete loss, with diverse ecological consequences. It is therefore critical to identify in space and time the change processes that lead [...] Read more.

Variability in the effects of disturbances and extreme climate events can lead to changes in tree cover over time, including partial or complete loss, with diverse ecological consequences. It is therefore critical to identify in space and time the change processes that lead to tree cover change. Studies of change are often hampered by the lack of data capable of consistently detecting different types of change. Using the Landsat satellite record to create a long time-series of land cover and land cover change, the U.S. Geological Survey Land Change Monitoring Assessment and Projection (LCMAP) project has made an annual time series of land cover across the conterminous United States for the period 1985 to 2018. Multiple LCMAP products analyzed together with map validation reference plots provide a robust basis for understanding tree cover change. In LCMAP (Collection 1.2), annual change detection is based on harmonic model breaks calculated at each Landsat pixel from the Continuous Change Detection and Classification (CCDC) algorithm. The results showed that the majority of CCDC harmonic model breaks (signifying change) indicated partial tree cover loss (associated with management practices such as tree cover thinning) as compared to complete tree cover loss (associated with practices like clearcut harvest or fire disturbance). Substantially fewer occurrences of complete tree cover loss were associated with change in land cover state. The area of annual tree cover change increased after the late 1990s and stayed high for the rest of the study period. The reference data showed that tree harvest dominated across the conterminous United States. The majority of tree cover change occurred in evergreen forests. Large estimates of disturbance-related tree cover change indicated that tree cover loss may have previously been underreported due to omission of partial tree cover loss in prior studies. This has considerable implications for forest carbon accounting along with tracking ecosystem goods and services. Full article

(This article belongs to the Special Issue Effects of Disturbances and Climate Change on Woody Plants)

► Show Figures

Figure 1

16 pages, 4162 KiB

Open AccessEditor’s ChoiceArticle

Potential Distribution Projections for Senegalia senegal (L.) Britton under Climate Change Scenarios

by Jiaqi Fang, Jianfei Shi, Ping Zhang, Minghao Shao, Na Zhou, Yongdong Wang and Xinwen Xu

Forests 2024, 15(2), 379; https://doi.org/10.3390/f15020379 - 18 Feb 2024

Cited by 3 | Viewed by 1746

Abstract

The gum acacia Senegalia senegal (L.) Britton (Fabales: Fabaceae) is a drought-tolerant plant belonging to the genus Acacia of the Leguminosae family, possessing significant economic and ecological value. Despite its importance, there is a knowledge gap regarding the potential impact of climate change [...] Read more.

The gum acacia Senegalia senegal (L.) Britton (Fabales: Fabaceae) is a drought-tolerant plant belonging to the genus Acacia of the Leguminosae family, possessing significant economic and ecological value. Despite its importance, there is a knowledge gap regarding the potential impact of climate change on the distribution of S. senegal, crucial for the conservation of plant resources and optimizing its use in introductory silviculture. In this study, we selected 23 environmental variables and utilized the optimized maximum entropy (MaxEnt) model to analyze the key environmental factors affecting the distribution of S. senegal worldwide and simulate the current and future distribution range of S. senegal in Pakistan under the SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 climate change scenarios. The results highlight key environmental factors influencing the distribution of S. senegal, including BIO3 (isothermally), BIO4 (coefficient of seasonal variation of temperature), BIO11 (mean temperature of the coldest season), and BIO12 (annual precipitation). Regions with higher and less fluctuating temperatures exhibit a higher potential for S. senegal distribution. Currently, suitable habitats of S. senegal are concentrated in the southern region of Pakistan, covering provinces such as Punjab, Sindh, and Balochistan, with highly suitable habitats accounting for 6.06% of the total area. Under the current climatic conditions, this study identifies the spatial patterns of suitable habitats and their concentration in specific regions. With climate change, a notable expansion of suitable habitats towards higher latitudes is observed, with the most significant expansion under the extremely severe climate change scenario (SSP5-8.5), reaching 223.45% of the current level. The results of this study enhance our understanding of the dynamics of S. senegal distribution under climate change and offer valuable insights into the long-term introduction of S. senegal for afforestation and soil conservation in Pakistan. This study provides theoretical support for the sustainable development of the local ecosystem and socio-economy, emphasizing the importance of proactive measures to adapt to changing climatic conditions. Full article

(This article belongs to the Section Forest Meteorology and Climate Change)

► Show Figures

Figure 1

18 pages, 25908 KiB

Open AccessEditor’s ChoiceArticle

Spruce Protection against Ips typographus with Anti-Attractant Blend of Tree-Based Semiochemicals: From Small Experimental Plots to Stand Scales

by Rastislav Jakuš, Aleksei Trubin, Vivek Vikram Singh, Khodabakhsh Zabihi, Anna Jirošová, Roman Modlinger, Andrej Majdák, Nataliya Korolyova, Antonioni Acacio Campos Moliterno, Jaroslav Kašpar, Martin Slavík, Peter Surový, Marek Turčáni and Fredrik Schlyter

Forests 2024, 15(2), 356; https://doi.org/10.3390/f15020356 - 12 Feb 2024

Cited by 4 | Viewed by 1890

Abstract

Tree-killing bark beetles require rapid management, such as anti-attractants, to stop the enlargement of attack hot-spots. We tested two newer anti-attractant blends, both without verbenone and one with the addition of trans-4-thujanol, in traps against standard pheromone baits for inhibition of catch. [...] Read more.

Tree-killing bark beetles require rapid management, such as anti-attractants, to stop the enlargement of attack hot-spots. We tested two newer anti-attractant blends, both without verbenone and one with the addition of trans-4-thujanol, in traps against standard pheromone baits for inhibition of catch. Both blends provided effective catch reduction (>95%). We also tested these anti-attractant blends in tree protection experiments for two years. We had experimental plots with a center of an anti-attractant protected tree zone, with no traditional control area, but we followed tree kills in 10 m wide concentric rings to 100 m. In 2020, we had 12 plots, and 9 plots in 2021. Monitoring by low-strength pheromone traps followed beetle flight averaging 300/trap during the shorter period, August 2020, and 5000/trap during the longer period, May to August 2021. The blends of anti-attractants were 100% effective in avoiding tree mortality in both treated trees and their surroundings. There were no bark beetle attacks on any treated trees, and there was zero tree mortality up to 19 m in 2020, and up to 30 m in 2021, thus full protection to circa 20 m. The density of killed trees then increased from close to zero, over 20 to 50 m, reaching a level of ca 30 (trees/ha) then declined. The spatial pattern of tree mortality on our experimental plots was highly heterogeneous and individual 10m-ring data points on tree kill density could not be statistically separated. In contrast, a non-linear regression model showed a continuous increase of attacks over the distance from the center to a peak ca 60m, followed by a decline. This model agrees partly with the only similar study in the literature, but importantly, it does not give a peak of kill density at distances between the first and second rings close to treatment zones. Such patterns of close-quarter kills have been observed as a “switching” of attack in this and other scolytid systems manipulated by anti-attractants, but not in the present study, likely due to the elimination of verbenone from our blends. Full article

(This article belongs to the Special Issue Risk Assessment and Management of Forest Pest Outbreaks)

► Show Figures

Figure 1

21 pages, 836 KiB

Open AccessEditor’s ChoiceReview

Driving Efficiency and Competitiveness: Trends and Innovations in ERP Systems for the Wood Industry

by Karla Vukman, Kristina Klarić, Krešimir Greger and Ivana Perić

Forests 2024, 15(2), 230; https://doi.org/10.3390/f15020230 - 25 Jan 2024

Cited by 2 | Viewed by 4061

Abstract

Enterprise Resource Planning (ERP) systems offer various functionalities to support an organization’s core functions. However, many anticipated benefits often need to materialize due to business context changes and users’ high expectations. Continuous adaptation and improvement are necessary to address user disappointments. This research [...] Read more.

Enterprise Resource Planning (ERP) systems offer various functionalities to support an organization’s core functions. However, many anticipated benefits often need to materialize due to business context changes and users’ high expectations. Continuous adaptation and improvement are necessary to address user disappointments. This research focuses on ERP systems, exploring key factors influencing the success of their implementation. Recognizing challenges in ERP system implementation, this study provides a comprehensive literature review, identifying essential and contemporary Critical Success Factors (CSFs) influenced by technological advancements. Addressing challenges specific to the wood industry, this research introduces additional industry-adapted CSFs, including industry adaptability, integration with production machinery, effective warehouse management, and supply chain tracking. Furthermore, this paper emphasizes the need for continuous adaptation and improvement of ERP systems, especially in light of current trends and technological achievements. This study recommends a holistic approach, considering traditional or essential CSFs while adapting to new trends. Critical success factors in ERP implementation in the next decade involve considering cloud technology, artificial intelligence and machine learning, data security, mobile access, IoT integration, user experience, and training. The main objective of this paper is to identify the latest CSFs in ERP implementation. This research highlights essential success factors in ERP implementation, and contemporary trends in ERP implementation with a particular focus on the specifics of wood industry. While organizations should aim to maximize the potential of ERP systems, they should also acknowledge the crucial role played by human intervention in the effective and responsible implementation of artificial intelligence. Full article

(This article belongs to the Special Issue Impact of Global Economic Changes on the Wood-Based Industry)

57 pages, 18765 KiB

Open AccessEditor’s ChoiceArticle

Three Censuses of a Mapped Plot in Coastal California Mixed-Evergreen and Redwood Forest

by Gregory S. Gilbert, Sarah G. Carvill, Alexander R. Krohn and Alexander S. Jones

Forests 2024, 15(1), 164; https://doi.org/10.3390/f15010164 - 12 Jan 2024

Cited by 1 | Viewed by 1994

Abstract

Large, mapped forest research plots are important sources of data to understand spatial and temporal changes in forest communities in the context of global change. Here, we describe the data from the first three censuses of the 16-ha UC Santa Cruz Forest Ecology [...] Read more.

Large, mapped forest research plots are important sources of data to understand spatial and temporal changes in forest communities in the context of global change. Here, we describe the data from the first three censuses of the 16-ha UC Santa Cruz Forest Ecology Research Plot, located in the Mediterranean-climate forest on the central coast of California, USA. The forest includes both mixed-evergreen forest and redwood-dominated forest and is recovering from significant logging disturbances in the early 20th century. Each woody stem with a diameter ≥ 1 cm at 1.3 m was mapped, tagged, identified, and measured, with censuses performed at ~5-year intervals. The first census included just 6 ha (previously described), and the area was then expanded to 16 ha in the second census. We describe the temporal dynamics of the forest in the original 6 ha, as well as the structure and temporal dynamics of the full 16 ha. The community includes 34 woody species, including 4 gymnosperm and 9 angiosperm tree species, 18 species of shrubs, and 3 species of lianas. The community includes eight non-native species, representing less than 0.5% of the stems. More than half the species show greater rates of mortality than recruitments, reflective of a dynamic forest community. Over a decade, the number of living woody stems has declined, but the basal area has increased, reflecting a self-thinning process. Full article

(This article belongs to the Section Forest Ecology and Management)

► Show Figures

Figure 1

22 pages, 4704 KiB

Open AccessEditor’s ChoiceArticle

Effects of Climate Change on Scots Pine (Pinus sylvestris L.) Growth across Europe: Decrease of Tree-Ring Fluctuation and Amplification of Climate Stress

by Jakub Brichta, Václav Šimůnek, Lukáš Bílek, Zdeněk Vacek, Josef Gallo, Stanisław Drozdowski, José Alfredo Bravo-Fernández, Bill Mason, Sonia Roig Gomez, Vojtěch Hájek, Stanislav Vacek, Václav Štícha, Pavel Brabec and Zdeněk Fuchs

Forests 2024, 15(1), 91; https://doi.org/10.3390/f15010091 - 3 Jan 2024

Cited by 9 | Viewed by 2657

Abstract

From an economic perspective, Scots pine (Pinus sylvestris L.) is one of Europe’s most important tree species. It is characterized by its wide ecological adaptability across its natural range. This research aimed to evaluate the forest structure, productivity and especially radial growth [...] Read more.

From an economic perspective, Scots pine (Pinus sylvestris L.) is one of Europe’s most important tree species. It is characterized by its wide ecological adaptability across its natural range. This research aimed to evaluate the forest structure, productivity and especially radial growth of heterogenous pine stands in 16 research plots in the Czech Republic, Poland, Spain and Great Britain. The study assessed the tree-ring formation and its relationship to climate change for each country, using 163 dendrochronological samples. The stand volume of mature pine forest ranged between 91 and 510 m³ ha⁻¹, and the carbon sequestration in the tree biomass was 40–210 t ha⁻¹. The stands had a prevailing random distribution of trees, with a high vertical structure close to selection forests (forest stands with typical very diverse height, diameter and age structure). Spectral analyses showed a substantial decrease in fluctuations in the tree-ring index and a loss in natural growth cyclicity in the last thirty years. The results also evinced that mean air temperature was the most important factor influencing the radial growth compared to precipitation totals. Pine thrives in precipitation-stable locations, as shown by the results from Great Britain. The conclusions of this study confirm the fundamental effect of ongoing global climate change on the dynamics and growth of pine forests in Europe. Full article

(This article belongs to the Special Issue Tree Growth and Physiological Properties under Ongoing Global Climate Change)

► Show Figures

Figure 1

15 pages, 4497 KiB

Open AccessEditor’s ChoiceArticle

Botryosphaeriaceae Species Associated with Stem Canker, Shoot Blight and Dieback of Fraxinus ornus in Italy

by Alessandra Benigno, Chiara Aglietti, Giovanni Rossetto, Carlo Bregant, Benedetto Teodoro Linaldeddu and Salvatore Moricca

Forests 2024, 15(1), 51; https://doi.org/10.3390/f15010051 - 26 Dec 2023

Viewed by 1971

Abstract

A severe dieback of flowering ash (Fraxinus ornus L.) has been observed in north-central Italy in the last decades. Symptoms include typical sunken, light-brown cankers on the stem and branches; vascular discoloration; tip and shoot dieback; and foliage necroses. The disease was [...] Read more.

A severe dieback of flowering ash (Fraxinus ornus L.) has been observed in north-central Italy in the last decades. Symptoms include typical sunken, light-brown cankers on the stem and branches; vascular discoloration; tip and shoot dieback; and foliage necroses. The disease was more evident at the beginning of the growing season, and more severe on young regeneration. Six Botryosphaeriaceae species were consistently isolated from symptomatic plant tissues: Botryosphaeria dothidea, Diplodia fraxini, Diplodia subglobosa, Dothiorella iberica, Dothiorella omnivora and Neofusicoccum parvum. B. dothidea and D. fraxini expressed higher aggressiveness and showed a widespread incidence, being the species most frequently associated with cankers; the other four species were less virulent and more erratic, occurring mainly on succulent branch tips and foliage. Isolates were characterized using morphological and molecular approaches (colony/conidial phenotyping and rDNA-ITS genotyping). Phylogenetic analysis provided congruent phylogenies depicting the relationships of the six taxa with the most closely related conspecifics. Pathogenicity tests on 2-year-old seedlings confirmed the higher virulence of B. dothidea and D. fraxini. Extensive, multi-year field surveys at different sites supported the hypothesis that climatic vagaries, mainly heat, water and drought stresses, impaired tree health and vigor, facilitating infection and pervasive colonization by these Botryosphaeriaceae species. Environmental stressors are thus the key factor bringing the six fungal pathogens together in a multitrophic interaction with F. ornus in a novel, lethal fashion. Full article

(This article belongs to the Special Issue Forest Pathology and Entomology—Series II)

► Show Figures

Figure 1

13 pages, 2099 KiB

Open AccessEditor’s ChoiceArticle

Temporal Variability in Soil Greenhouse Gas Fluxes and Influencing Factors of a Primary Forest on the Eastern Qinghai-Tibetan Plateau

by Shun Liu, Da Luo, Gexi Xu, Jiamei Wu, Qiuhong Feng and Zuomin Shi

Forests 2023, 14(11), 2255; https://doi.org/10.3390/f14112255 - 16 Nov 2023

Viewed by 1390

Abstract

Soil greenhouse gas (GHG) fluxes relate to soil carbon and nitrogen budgets and have a significant impact on climate change. Nevertheless, the temporal variation and magnitude of the fluxes of all three major GHGs (CO₂, CH₄ and N₂O) [...] Read more.

Soil greenhouse gas (GHG) fluxes relate to soil carbon and nitrogen budgets and have a significant impact on climate change. Nevertheless, the temporal variation and magnitude of the fluxes of all three major GHGs (CO₂, CH₄ and N₂O) and their influencing factors have not been elucidated clearly in primary forests on the eastern Qinghai-Tibetan Plateau. Herein, field chamber GHG fluxes from May to November, soil microbial community and enzyme activity were analyzed in a fir-dominated (Abies fargesii var. faxoniana) primary forest. The emission rates of CO₂ and N₂O ranged between 64.69–243.22 mg CO₂ m⁻² h⁻¹ and 1.69–5.46 ug N₂O m⁻² h⁻¹, exhibiting a temporally unimodal pattern with a peak in July. The soil acted as a CH₄ sink, and the uptake rate varied between 52.96 and 84.67 μg CH₄ m⁻² h⁻¹ with the higher uptake rates in June and November. The temporal variation in the CO₂ flux was significantly correlated with the geometric mean of enzyme activities, suggesting that the soil CO₂ flux was determined by microbial activity rather than soil microbial biomass. The soil N₂O flux was positively related to nitrate concentration with marginal significance, probably because N₂O was a byproduct of nitrification and denitrification processes. The soil CH₄ uptake was closely associated with methanotrophic biomass (18:1ω7c). The results highlight divergent temporal dynamics of GHG fluxes owing to different driving mechanisms and an important CH₄ sink in the primary forest soil, helping to evaluate the carbon and nitrogen budgets of primary forests on the eastern Qinghai-Tibetan Plateau. Full article

(This article belongs to the Section Forest Soil)

► Show Figures

Figure 1

12 pages, 1891 KiB

Open AccessEditor’s ChoiceArticle

Impact of Chemical Composition on Eucalyptus Wood Clones for Sustainable Energy Production

by Túlio A. S. Vieira, Paulo F. Trugilho, Sónia A. C. Carabineiro, Antônio José Vinha Zanuncio, Amélia Guimarães Carvalho and Monique Branco-Vieira

Forests 2023, 14(11), 2240; https://doi.org/10.3390/f14112240 - 14 Nov 2023

Cited by 5 | Viewed by 3731

Abstract

The energy potential of wood biomass is significantly shaped by its chemical composition. Analyzing the chemical composition of wood biomass and understanding the correlations between these parameters and wood combustibility are essential stages in the selection process of Eucalyptus clones tailored for firewood [...] Read more.

The energy potential of wood biomass is significantly shaped by its chemical composition. Analyzing the chemical composition of wood biomass and understanding the correlations between these parameters and wood combustibility are essential stages in the selection process of Eucalyptus clones tailored for firewood production and energy generation. In this study, we aimed to evaluate the impact of chemical composition on the direct combustibility of Eucalyptus clones. We examined the structural chemical composition and conducted proximate analysis, including fixed carbon, volatile material, and ash, to investigate the relationship between proximate composition and wood combustibility parameters. Our findings revealed significant correlations between wood chemical composition and combustibility parameters. In particular, lignin content, ethanol-soluble extractives, and xylose demonstrated inverse relationships with the parameters of maximum combustion rate, combustion characteristic index, and ignition index. Conversely, holocellulose content, cold-water-soluble extractives, and glucose exhibited direct correlations with the same combustibility parameters. Furthermore, fixed carbon and volatile matter contents demonstrated direct and inverse correlations, respectively, with ignition temperature. These findings have significant implications for enhancing the efficiency and sustainability of biomass energy production. Full article

(This article belongs to the Section Wood Science and Forest Products)

► Show Figures

Figure 1

14 pages, 3360 KiB

Open AccessEditor’s ChoiceArticle

Utilizing SIFT-MS and GC-MS for Phytoncide Assessment in Phytotron: Implications for Indoor Forest Healing Programs

by Yeji Choi, Geonwoo Kim, Soojin Kim, Jae Hyoung Cho and Sujin Park

Forests 2023, 14(11), 2235; https://doi.org/10.3390/f14112235 - 13 Nov 2023

Cited by 1 | Viewed by 5963

Abstract

This study addresses the growing need for phytoncide studies, driven by the demand to design indoor forest healing programs, including virtual reality experiences, for patients unable to visit actual forests. Previous studies have struggled to establish consistent phytoncide emission patterns in outdoor forest [...] Read more.

This study addresses the growing need for phytoncide studies, driven by the demand to design indoor forest healing programs, including virtual reality experiences, for patients unable to visit actual forests. Previous studies have struggled to establish consistent phytoncide emission patterns in outdoor forest environments owing to varying microclimates and abiotic factors. In addition, the traditional gas chromatography–mass spectroscopy (GC-MS) method presents field measurement challenges, whereas the selected ion flow tube (SIFT)-MS method offers improved efficiency. This study concentrated on a controlled phytotron environment and compared the GC-MS and SIFT-MS findings, revealing similar emission trends with slightly higher SIFT-MS concentrations. Daily phytoncide emissions fluctuated with light intensity and abiotic stressors. Both methods consistently detected pinenes, primarily emitted by Pinus strobus L. seedlings, in the phytotron. Statistical analysis confirmed the compatibility between GC-MS and SIFT-MS results, supporting the use of SIFT-MS for forest phytoncide assessment. In the second phase, the phytoncide emissions were assessed indoors, outdoors, and in the phytotron, highlighting the superiority of the phytotron under controlled conditions. Despite certain limitations, this study underscores the value of phytotron-based measurements for indoor forest healing programs and the potential adoption of SIFT-MS in future field-based phytoncide research. Full article

(This article belongs to the Special Issue Forest, Trees, Human Health and Wellbeing)

► Show Figures

Figure 1

13 pages, 10700 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of Forestry Component Survival in Plots of the Program “Sembrando Vida” (Sowing Life) Using Drones

by José Luis Gallardo-Salazar, Cuauhtémoc Sáenz-Romero, Roberto A. Lindig-Cisneros, Arnulfo Blanco-García and Verónica Osuna-Vallejo

Forests 2023, 14(11), 2117; https://doi.org/10.3390/f14112117 - 24 Oct 2023

Cited by 2 | Viewed by 2043

Abstract

Reforestation is one of the main actions undertaken to mitigate the effects of climate change. In Mexico, the Federal Government program “Sembrando Vida” (Sowing Life) is currently the most important reforestation effort. It aims to recoup forest cover and achieve food [...] Read more.

Reforestation is one of the main actions undertaken to mitigate the effects of climate change. In Mexico, the Federal Government program “Sembrando Vida” (Sowing Life) is currently the most important reforestation effort. It aims to recoup forest cover and achieve food self-sufficiency through the establishment of agroforestry systems. The evaluation of tree survival in reforested areas helps to identify achievements and failures, as well as aspects of the program that require improvement. However, given the magnitude of this program, evaluation using traditional methodologies is labor-intensive and costly. In this context, drones equipped with high-resolution cameras are a promising tool. The objective of this study was to evaluate the feasibility of using drones to monitor tree survival in reforested areas. This study was conducted in 12 randomly chosen plots, benefited by the “Sembrando Vida” program, located on the Purépecha Plateau in the state of Michoacán, in central–western Mexico. Field surveys with GPS were conducted to record the total number of live and dead forest-tree seedlings. Simultaneously, high-resolution images were captured using a DJI Phantom 4 Pro drone equipped with an RGB camera for subsequent visual interpretation in a geographic information system to determine the status of each seedling and calculate the rates of survival. ANOVA was performed to compare the survival calculated using the drone images compared to that recorded in the field. No significant difference was found between survival estimated using the drone and that recorded directly in the field in any of the study plots, although the drone overestimated survival by an average of 6%, mostly due to the presence of dead seedlings that had already lost their foliage and were thus missed when scoring the RGB image. It is therefore concluded that the estimation of survival using drones is a reliable method. For future research, it is recommended to evaluate machine-learning algorithms in terms of detecting both living and dead trees in reforested sites. It is also recommended to use multispectral thermal cameras and LiDAR technology to broaden the knowledge of the different levels of vigor/stress present in the vegetation. Full article

(This article belongs to the Special Issue Forest Species Distribution, Diversity and Growth under Climate Change)

► Show Figures

Figure 1

14 pages, 4437 KiB

Open AccessEditor’s ChoiceArticle

Assessing the Potential of Urban Trees to Accumulate Potentially Toxic Elements: A Network Approach

by Marija Matić, Dragana Pavlović, Veljko Perović, Dragan Čakmak, Olga Kostić, Miroslava Mitrović and Pavle Pavlović

Forests 2023, 14(11), 2116; https://doi.org/10.3390/f14112116 - 24 Oct 2023

Cited by 2 | Viewed by 1592

Abstract

In urbanized areas, mitigating the negative effects of pollutants from various anthropogenic sources is one of the most important issues in planning urban functioning and development. In this sense, urban vegetation plays one of the most important roles. The aim of this study [...] Read more.

In urbanized areas, mitigating the negative effects of pollutants from various anthropogenic sources is one of the most important issues in planning urban functioning and development. In this sense, urban vegetation plays one of the most important roles. The aim of this study was to investigate the performance of network analysis (NA) as a novel and potential method for determining different associations between potentially toxic elements (PTEs) in leaves of urban trees, their accumulation capacity and ecophysiological response to different types of pollution in urban environments. The results of NA showed that there is no association between elements in species that have lower or higher efficiency in uptake of PTEs, leading to the conclusion that the elements do not depend on mutual association but on accumulation itself. It was also found that there are differences in the content of photosynthetic pigments and carotenoids among the studied species, but these differences are not reflected in the values of the photosynthetic efficiency parameters. Overall, the studied species have good ecophysiological potential for growth and existence in the urban environment, despite the varying ability to accumulate elements and the different associations between them. This is the first study to investigate the interactions between PTEs in leaves of urban tree species using NA and provides a good basis for future research under different environmental conditions. Full article

(This article belongs to the Special Issue The Response of Trees to Air Pollution in Urban Forests)

► Show Figures

Figure 1

16 pages, 3931 KiB

Open AccessEditor’s ChoiceArticle

Responses of Stream Water Temperature to Water Levels in Forested Catchments of South Korea

by Sooyoun Nam, Honggeun Lim, Byoungki Choi, Qiwen Li, Haewon Moon and Hyung Tae Choi

Forests 2023, 14(10), 2085; https://doi.org/10.3390/f14102085 - 18 Oct 2023

Cited by 2 | Viewed by 1376

Abstract

Event flow characteristics were evaluated based on temperature and level of stream water in 22 forested catchments (area: 13.2–281.4 ha) to investigate sustainable flood management measures. Temperature and stream water levels were during 346 rainfall events in the summer season (July–September) from 2020 [...] Read more.

Event flow characteristics were evaluated based on temperature and level of stream water in 22 forested catchments (area: 13.2–281.4 ha) to investigate sustainable flood management measures. Temperature and stream water levels were during 346 rainfall events in the summer season (July–September) from 2020 to 2022. Rising stream water levels responded to falling stream water temperature between ≤100 and >100 ha forested catchments in two types of time of concentration. Stream water temperature decreased by 3.0 °C when the stream water level increased by up to 0.9 m during rainfall events. Falling stream water temperature at two types of time of concentration was negatively correlated with total precipitation and rising stream water level. Based on the relatively high value of regression and cumulative frequency distribution, the estimated rising stream water level was appropriate in small catchments (≤100 ha) when the stream water temperature decreased, and the stream water level increased during rainfall events. Rising stream water levels and falling stream water temperatures are responses to catchment-scale effects, which are influenced by the nature and rapidity of the hydrological responses. Therefore, the results of the present study indicate that spatial and temporal differences in thermal responses of stream water temperature to water levels were controlled by catchment-scale effects under rapidly changing rainfall. Full article

(This article belongs to the Special Issue Hydrology and Ecosystem Services in Forests)

► Show Figures

Figure 1

19 pages, 1911 KiB

Open AccessEditor’s ChoiceArticle

Modeling Above-Ground Carbon Dynamics under Different Silvicultural Treatments on the McDonald–Dunn Research Forest

by Catherine Carlisle, Stephen Fitzgerald and Hailemariam Temesgen

Forests 2023, 14(10), 2090; https://doi.org/10.3390/f14102090 - 18 Oct 2023

Cited by 1 | Viewed by 14753

Abstract

Forest management decisions affect carbon stock and rates of sequestration. One subject of debate is the rotation age that will optimize sequestration over extended periods. Some argue that shorter rotations facilitate greater sequestration rates due to the accelerated growth rates of younger trees [...] Read more.

Forest management decisions affect carbon stock and rates of sequestration. One subject of debate is the rotation age that will optimize sequestration over extended periods. Some argue that shorter rotations facilitate greater sequestration rates due to the accelerated growth rates of younger trees compared to mature or old-growth trees. Others maintain that frequent harvesting will not allow forest carbon to rebound after each subsequent rotation, and thus more extended periods between clearcutting is the superior choice. These contrasting viewpoints are mirrored regarding the impact of thinning treatments, in that either thinning will enhance forest carbon uptake by facilitating improved and sustained r growth of residual trees or removing any above-ground biomass will outweigh the yields. This study aims to compare the different suites of management decisions and identify practical combinations of rotation ages and thinning applications that will optimize carbon sequestration while meeting other objectives over a 240-year projection timeframe. Stand development under different harvest rotations and thinning specifications was modeled using a Forest Vegetation Simulator (FVS). We found that site productivity was the primary determinant in stand-above-ground carbon dynamics under various management scenarios. Thus, the optimal rotation age/thinning treatment combinations differed between site classes. High productivity stands were estimated to sequester the most above-ground live carbon with 60-year rotations with a low-intensity thin at age 40. Moderately productive stands performed the best with 80-year rotations when two low-intensity thinning treatments were applied between harvests. For high and moderate productivity stands, estimates of gross carbon increased when two low or moderate-intensity thinning treatments were applied within 80- or 120-year rotations. High-intensity thinning treatments reduced total carbon sequestered over the 240-year projection timeframe for all productivity levels and rotation ages, except for low productivity stands under 120-year rotations. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

► Show Figures

Figure 1

13 pages, 2053 KiB

Open AccessEditor’s ChoiceArticle

Ecophysiological Behavior of Fagus sylvatica L. Growing at Its Southern Distribution Limit: Insights for Understanding the Fate of the European Beech under Warmer and Dryer Growth Conditions

by Maria Prigoliti, Maria Teresa Chiofalo, Francesco Petruzzellis, Maria Assunta Lo Gullo and Patrizia Trifilò

Forests 2023, 14(10), 2058; https://doi.org/10.3390/f14102058 - 15 Oct 2023

Cited by 2 | Viewed by 1789

Abstract

In the last 20 years, a significant mortality of Fagus sylvatica L. (European beech) has been documented in central and northern European forests. Surprisingly, no beech die off occurred at the southern limit. This fact leads us to hypothesize that European beech populations [...] Read more.

In the last 20 years, a significant mortality of Fagus sylvatica L. (European beech) has been documented in central and northern European forests. Surprisingly, no beech die off occurred at the southern limit. This fact leads us to hypothesize that European beech populations growing at the southern limit of the distribution might have a significant phenotypic plasticity to better cope with low water availability and rising temperatures. To check this hypothesis, we evaluated the ecophysiological behavior of F. sylvatica growing along an altitudinal transect in Calabria (Italy). We selected three study sites (750 m a.s.l., 976 m a.sl. m a.s.l., 1450 m a.s.l.) showing narrow ranges of temperature, rainfall and air humidity. Trees growing at 976 m a.s.l. showed the highest stomatal conductance values during the entire experimental period. The lowest gas exchange and highest leaf mass area were recorded in plants growing at 750 m a.s.l. In the European beech growing at 1450 m a.s.l., higher vessel density, lower mean vessel diameter and higher vessel grouping index values were recorded. Overall, our results highlighted that the measured populations show a considerable phenotypic plasticity leading them to adjust anatomical and physiological traits in response to narrow ranges of environmental parameters. Despite that, the distribution of F. sylvatica seems to be limited to areas with a growing season rainfall of at least 400 mm and vapor pressure deficit (VPD) values < 3 kPa, which may represent the main environmental thresholds which strongly limit the beech growth and, therefore, influence the ability of this species to cope with future environmental conditions. Full article

(This article belongs to the Special Issue Forest Sensitivity to the Cumulative Effects of Repeated Drought and Other Stresses)

► Show Figures

Figure 1

18 pages, 6358 KiB

Open AccessEditor’s ChoiceArticle

Barcoding Hymenoptera: 11 Malaise Traps in Three Thai Forests: The First 68 Trap Weeks and 15,338 Parasitoid Wasp Sequences

by Donald L. J. Quicke, Paul D. N. Hebert, Mikko Pentinsaari and Buntika A. Butcher

Forests 2023, 14(10), 1991; https://doi.org/10.3390/f14101991 - 3 Oct 2023

Cited by 5 | Viewed by 2792

Abstract

We report the results of DNA barcoding week-long Malaise trap catches from 11 sites in three Thai conservation areas, concentrating on the parasitoid Hymenoptera, particularly the superfamily Ichneumonoidea. From a total of 15,338 parasitoid wasp sequences, 13,473 were barcode compliant and could be [...] Read more.

We report the results of DNA barcoding week-long Malaise trap catches from 11 sites in three Thai conservation areas, concentrating on the parasitoid Hymenoptera, particularly the superfamily Ichneumonoidea. From a total of 15,338 parasitoid wasp sequences, 13,473 were barcode compliant and could be assigned to a family based on morphology and sequence data. These collectively represented 4917 unique BINs (putative species) in 46 families, with the Scelionidae, Ichneumonidae, Eulophidae, Braconidae and Platygastridae being, by far, the most abundant. Spatial proximity had a strong positive effect on the numbers of BINs shared between traps. Full article

(This article belongs to the Special Issue DNA Barcoding for Species Identification of Forest Organisms)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Editor’s Choice Articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI