Un libro per conoscere l'ecologia e la gestione dei boschi di neoformazione delle Alpi, con parti... more Un libro per conoscere l'ecologia e la gestione dei boschi di neoformazione delle Alpi, con particolare riferimento al Trentino, utile a ricercatori, studenti universitari ed esperti nella gestione delle foreste e del paesaggio rurale e peri-urbano. Dopo l'analisi storica delle foreste trentine e delle dinamiche socio-economiche ad esse collegate, vengono descritti i modi e i tempi che caratterizzano le successioni secondarie. Il terzo e quarto capitolo sono dedicati al metodo di rilevamento e alle caratteristiche generali che questi boschi assumono in Trentino. Il quinto capitolo è dedicato alla loro tipologia, ai trattamenti, compresi i miglioramenti ambientali, e alle dinamiche specifiche dei singoli tipi neoforestali. L'ultimo capitolo affronta la gestione e la pianificazione dal punto di vista del paesaggio in abbandono colturale, nell'ottica di conservazione della biodiversità, non trascurando l'eventualità di ricorrere alle trasformazioni di coltura. Concludono la trattazione una chiave di riconoscimento e 14 schede ricche di dati sintetici relativi a caratteri tipici dei boschi di recente insediamento. Disegni, schemi e fotografie arricchiscono la veste grafica del volume e contribuiscono a descrivere tecniche di gestione e caratteri ecologici.
This book focuses on the features and processes of the recent secondary forests of the Alps, where human and former land use influence is thought to be high, with special emphasis on a central-eastern Italian region (Trento Province). After an historical analysis of the forest changes and their socio-economical driving forces, the author discusses the temporal and spatial patterns of secondary successions leading to the formation of secondary woodlands. The third and fourth chapters deal with the survey method and the general characteristics of these woodlands in the Trento Province. The fifth chapter contains the classification, treatments, including restoration ecology, and dynamics associated to each neo-forest type. The last chapter is concerned with the management actions and planning approaches from the point of view of the abandoned rural and suburban landscapes. Biodiversity concerns, including the opportunities and risks related to forest conversion to the former land use, are outlined. There then follow a dichotomic key for the on-field identification of the neo-forest type and 14 sheets, where many data concerning attributes typical of recent secondary woodlands are reported. Pictures, diagrams and photographs help the reader understand management techniques and ecological characters.
Spatial patterns of vegetation arise from an interplay of functional traits, environmental charac... more Spatial patterns of vegetation arise from an interplay of functional traits, environmental characteristics and chance. The retreat of glaciers offers exposed substrates which are colonised by plants forming distinct patchy patterns. The aim of this study was to unravel whether patch-level landscape metrics of plants can be treated as functional traits. We sampled 46 plots, each 1 m × 1 m, distributed along a restricted range of terrain age and topsoil texture on the foreland of the Nardis glacier, located in the SouthEastern Alps, Italy. Nine quantitative functional traits were selected for 16 of the plant species present, and seven landscape metrics were measured to describe the spatial arrangement of the plant species' patches on the study plots, at a resolution of 1 cm × 1 cm. We studied the relationships among plant communities, landscape metrics, terrain age and topsoil texture. RLQ-analysis was used to examine trait-spatial configuration relationships. To assess the effect of terrain age and topsoil texture variation on trait performance, we applied a partial-RLQ analysis approach. Finally, we used the fourth-corner statistic to quantify and test relationships between traits, landscape metrics and RLQ axes. Floristically-defined relevé clusters differed significantly with regard to several landscape metrics. Diversity in patch types and size increased and patch size decreased with increasing canopy height, leaf size and weight. Moreover, more compact patch shapes were correlated with an increased capacity for the conservation of nutrients in leaves. Neither plant species composition nor any of the landscape metrics were found to differ amongst the three classes of terrain age or topsoil texture. We conclude that patch-level landscape metrics of plants can be treated as species-specific functional traits. We recommend that existing databases of functional traits should incorporate these type of data.
The species richness of hedges in an agricultural landscape may be determined by the environment ... more The species richness of hedges in an agricultural landscape may be determined by the environment and by the spatial processes which occur in that landscape. Here, we divided the environmental predictors into three groups: site conditions, hedge stand and landscape structure. We determined their independent and joint effects on the richness of four guilds of herbaceous species in 92 hedge stands in a north-Mediterranean intensive agricultural landscape. The fine—(at <250 m) and broad—(>550 m) spatial patterns of the key environmental predictors and the pure spatial effects on species richness were measured using a computation of the principal coordinates of a matrix of geographical neighbours integrated into a variation partitioning. The total explained variation of species richness among hedgerows was highest for wetland herbs (62 %), with increasing rates for rare plants (33 %), forest herbs (43 %) and arable weeds (47 %). 43–11 % of that variation was spatially structured and mostly explained by some of the key environmental predictors, such as proportion of a given landuse, presence of woody species and dead trees. This indicates that complex relationships between herbaceous species distribution and spatial processes exist in woody field margins and much of that is related to key factors which are spatially structured, both at fine or broad-scales, with implications for management and landuse planning.
The effectiveness of conservation interventions for maximizing biodiversity benefits from agri-en... more The effectiveness of conservation interventions for maximizing biodiversity benefits from agri-environment schemes (AESs) is expected to depend on the quantity of seminatural habitats in the surrounding landscape. To verify this hypothesis, we developed a hierarchical sampling design to assess the effects of field boundary type and cover of seminatural habitats in the landscape at two nested spatial scales. We sampled three types of field boundaries with increasing structural complexity (grass margin, simple hedgerow, complex hedgerow) in paired landscapes with the presence or absence of seminatural habitats (radius 0.5 km), that in turn, were nested within 15 areas with different proportions of seminatural habitats at a larger spatial scale (10 X 10 km). Overall, 90 field boundaries were sampled across a Mediterranean&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;region (northeastern Italy). We considered species richness response across three different taxonomic groups: vascular plants, butterflies, and tachinid flies. No interactions between type of field boundary and surrounding landscape were found at either 0.5 and 10 km, indicating that the quality of field boundary had the same effect irrespective of the cover of seminatural habitats. At the local scale, extended-width grass margins yielded higher plant species richness, while hedgerows yielded higher species richness of butterflies and tachinids. At the 0.5-km landscape scale, the effect of the proportion of seminatural habitats was neutral for plants and tachinids, while butterflies were positively related to the proportion of forest. At the 10-km landscape scale, only butterflies responded positively to the proportion of seminatural habitats. Our study confirmed the importance of testing multiple scales when considering species from different taxa and with different mobility. We showed that the quality of field boundaries at the local scale was an important factor in enhancing farmland biodiversity. For butterflies, AESs should focus particular attention on preservation&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;of forest patches in agricultural landscapes within 0.5 kin, as well as the conservation of seminatural habitats at a wider landscape scale.
Potential forest-related information which can be obtained from processing laser scanner data mak... more Potential forest-related information which can be obtained from processing laser scanner data make this technology extremely useful for management and assessment of forests. It is thoroughly documented in recent literature how specific forest characteristics can be estimated at stand, plot and single tree level using laser scanner surveys at corresponding scales. The high resolution models of the canopy surface and of the bare earth (terrain), and also the information obtained of the structure of the volume between ...
Research on changes in biodiversity due to the abandonment of forestry is important in understand... more Research on changes in biodiversity due to the abandonment of forestry is important in understanding the role of reserves in conservation. The aim of this study was to investigate whether changes have occurred in species richness, abundance and composition of ground, longhorn and bark beetles due to habitat changes as a result of the cessation of forest management. We surveyed ten managed and ten abandoned forest plots in two watersheds located in the north-eastern Italian alpine region, which share a common history of use, climate regimes, stand structure and topography. Ground beetles, and longhorn and bark beetles were collected with pitfall and flight-intercept window traps, respectively, from May to mid-October 2010. The three beetle taxa responded differently to changes in habitat features and management cessation. Differences in individual species responses between the two watersheds may indicate a role of management abandonment through its impact on forest habitat structure. For instance, ground beetle species mainly responded negatively to soil moisture and positively to understorey vegetation cover. Unexpectedly, saproxylic species re- sponded variably, and often negatively, to deadwood fea- tures in these forests, but did respond positively to the volume of standing Abies alba trees. The assemblages of carabids and bark beetles differed between the two water- sheds. Our results confirmed that 50 years of forest man- agement cessation resulted in changes in the biodiversity of beetles in alpine forests, likely due to their response to changes in habitat structure. Moreover, we expect that where the unplanned abandonment of forestry practices and habitat rewilding are undergoing, like in many mar- ginal areas of Europe, similar habitat structure dynamics and beetle responses are likely to occur spontaneously.
A new field of forestry science is required to assume the responsibilities that a new European re... more A new field of forestry science is required to assume the responsibilities that a new European regulation will give to Member States. Are silviculturists ready to share and improve scientific knowledge on the management of invasive tree species alien to Europe?
The objective of this study was to investigate a grid-based sampling design to determine the cros... more The objective of this study was to investigate a grid-based sampling design to determine the cross-scalar selection of habitat by a territorial animal species: the hazel grouse (Tetrastes bonasia L.). In each of three sites with increasing hazel grouse nest site density, three lattice grids were used to measure both the habitat variables and the species occurrence in 100 30 × 30 m cells. We calculated the average values for habitat variables, as well as use versus non-use by the species, at three spatial scales: small (1 × 1 cell), intermediate (2 × 2 cells) and large (3 × 3 cells). Generalised linear mixed models were integrated into a method of variation and hierarchical partitioning and used to assess the relationship between the habitat variables and the species preferences at each scale. In all scales, species selection was associated with ground layer composition. Selection was also associated with the composition of the woody layer and negatively associated with dominance of tor grass (Brachypodium rupestre (Host) Roem. & Schult.) at the two larger scales. Both litter cover and thinning contributed positively to the habitat selection at the two smaller scales. The other variables were significant only at one scale or explained a relatively low proportion of the variation at multiple scales. Neither the management nor the stand structure variables played a significant independent role across scales when compared with ground layer variables. The total variation explained was highest (ca. 90 %) at the large scale. This finding indicates the possibility of obtaining cross-scalar hazel grouse preferences from grid-based sampling, provided that spatial autocorrelation in the data is handled appropriately.
The woody component along field edges often provides the only permanent elements of structural an... more The woody component along field edges often provides the only permanent elements of structural and biological diversity in landscapes that have lost much of their naturalness to agriculture and urban use. The main aims of this study were (i) to investigate how four hedge stand types, i.e., systems of management distinguished on the basis of the natural and managed growth forms of trees and shrubs (low single-storied, high single-storied, two-storied and multi-storied), differ in their biometric parameters and (ii) to identify the primary management-related determinants of native woody species richness. The study used a large dataset of hedgerows (n=538) sampled in seven sites in Northern Italy. The four hedge stand types exhibited highly significant differences in size and biometric parameters. The multi-storied hedges, associated with the highest stand structural diversity index values, supported the highest number of tree species, followed by high single-storied hedges. The low single-storied hedge stand type contained the lowest number of species. We found a positive effect of hedge area as well as a marginal negative effect of basal area on native woody species richness. The management implications addressed by our study include conversion of single-storied into two- or multi-storied types, increasing hedge size and controlling hedge stand basal area
Although few undisturbed forests remain in Europe, forest reserves and deforested areas that are ... more Although few undisturbed forests remain in Europe, forest reserves and deforested areas that are no longer profitable have the potential to develop stand structures similar to those which preceded human disturbances. The direct effects of management cessation on forest diversity are confounded by many factors that should be controlled when comparing managed and abandoned stands. In the European Alps, however, the high variability of habitats makes it nearly impossible to find comparable stands located within forests large enough to be independent from the surrounding land. The aim of this study was to investigate the use of mixed models to compare deadwood and plant diversity between matched managed and unmanaged pairs of forests, with the hypothesis that their differences were due to direct effect of abandonment. Two neighbouring watersheds that were large enough to be independent from the surrounding forests were chosen. These watersheds had a common history of use, but one was non-intensively managed, while the other was untouched since 1957. Ten plots were randomly selected from each forest. Mixed models confirmed their matched topography and stand structure, while a similarity index confirmed their assignment to the same plant community. The unmanaged stand had higher soil nitrogen, higher Fagus sylvatica dendrological composition, higher tree species richness, higher dead logs and a different composition of the tree and understory layers. These results suggest that silver fir woodlands abandoned for more than 50years change spontaneously and that this approach may be an effective means for studying other forest communities.
Black locust (Robinia pseudoacacia L.) is a widespread alien tree species commonly thought to inf... more Black locust (Robinia pseudoacacia L.) is a widespread alien tree species commonly thought to influence plant assemblages. The aim of this study was to compare the plant diversity between black locust and native recent secondary stands within the European Mediterranean Mountains environmental zone. Spontaneous reforestation was detected by comparing historical aerial photographs and the most recent images. Distributed throughout a 2700 km2 hilly and piedmont area, 32 black locust and 32 paired native stands were selected and all vascular plant species were surveyed in a 100 m2 area. Analyses of the α and β-diversity were performed separately for six identified plant groups. Despite a clear difference in the tree diversity between the black locust and native recent secondary stands and a homogenisation of the tree layer by the black locust stands, we found only inconsistent hints for homogenisation of the ground-layer vegetation by the black locust stands. There is no evidence to suggest that the presence of black locust in recent secondary stands plays a major role in shaping the diversity of the understory plant groups compared to native stands.
In the Alps, many forests are under abandonment because of direct protection or the unprofitabili... more In the Alps, many forests are under abandonment because of direct protection or the unprofitability of timber production. The objective of this study was to analyse the effect of silviculture abandonment on the species richness and composition of epiphytic and dead wood-dwelling lichens in silver fir woodlands. An abandoned and a currently non-intensively managed forest watershed of the eastern Italian Alps that were matched for topography, stand structure, plant community and history of use were selected and randomly sampled for the lichen diversity of their silver fir mature stands. Generalised linear mixed models were used for the analyses of the species richness, whereas the species composition patterns were explored by redundancy analysis. The diversity of both of the lichen guilds were explained by the microhabitat conditions related to the contrasting management regimes, but they had opposite responses to the abandonment of the silvicultural activities. The epiphytic lichen communities were richer in species in the managed than in the abandoned silver fir woodlands. However, the effect of a 50 year management cessation on the epiphytic lichens may change in the long term when natural disturbances create gaps and increase the attributes of old-growth forests. The dead wood-dwelling lichen species richness was higher in the abandoned forest because an increased availability of types of dead wood is usually rare in managed forests. The dead wood-dwelling lichen communities of the managed forests were a subset of a more diverse community that was developing in the abandoned forest. Our results indicated that, in non-intensively managed silver fir mature stands, lichen diversity may benefit from the retention of logs and snags, which provide habitat features typical of old-growth forests.
In: Hedgerow Futures, edited by John Dover, pp. 135-146, 2012
Here we summarise the findings of a study investigating the environmental, management, and land u... more Here we summarise the findings of a study investigating the environmental, management, and land use factors that influence patterns of biodiversity in field margins in the Po Plain, Italy, and evaluate these habitats for their cultural and biodiversity value. We highlight four traditional management techniques of woody vegetation in field margins on the Po Plain, Italy, and make recommendations for further study to investigate the ecosystem services and cultural significance of these features
Through the classification of current and historical aerial photos between 1973 and 2006, we anal... more Through the classification of current and historical aerial photos between 1973 and 2006, we analysed the evolution of size, shape and connectivity of 59 mountain meadows (maggenghi) of the Pejo di- strict (Trentino, Northern Italy). The maggenghi are scattered patches within a forested matrix. We conducted the same analysis on an Austro-Hungarian cadastral map of 1859. The total surface covered by maggenghi was 137.4 ha in 1973, and decreased to 78.3 ha (57%) in 2006. The mean shape and connectivity index in 1973 are significantly lower than those of 2006. Within a 1-km radius around the studied patches, woodlands in- creased by 7% in the same time range. Among the 25 maggenghi present in 1958, 12 has been subdivided into 39 smaller fragments and 13 has been reduced in their size without any fragmentation. A general process of meadow patches evolution which included area and connectivity reduction and shape simplification has been noticed. This process is common to many other alpine landscapes. The study of these processes is fundamental for policies aimed to conservation of mountain meadows, as well as to identify the single patches deserving conservation for their current and historical landscape structure, as many studies report their significant effects on local floristic diversity.
Potential forest-related information can be obtained from processing data obtained from laser sca... more Potential forest-related information can be obtained from processing data obtained from laser scanning sensors making this technology extremely useful for forest management and
environmental assessment. It is thoroughly documented in recent literature how specific forest characteristics can be estimated at stand, plot and single tree level using laser scanner surveys at corresponding scales. The high resolution models of the canopy surface and of the bare earth (terrain), as well as the information obtained related to the structure of the volume between these two surfaces, concur at offering a more complete source of information not only for direct forestry-related applications, but also for connected disciplines such as hydrology, engineering, forest disturbances analysis and ecological assessment.
Having accurate and spatially distributed information over the above mentioned aspects give land assessment and management added value data to work with. Correct utilization
of laser scanner data can lead to the assessment of many characteristics usually obtained by ground surveys. Ground-plots require significant expenditure in terms of human effort,
economical investment and can be distributed on large areas only in limited number. The following paper shows the efforts which are being undertaken by scientific research towards testing laser scanner applications for forest and environmental sciences
The present landscape structure and function is the result of centuries of changes produced both ... more The present landscape structure and function is the result of centuries of changes produced both by natural processes and human driving forces. For centuries many mountain and hillside areas have been the subject of deforestation to create space for agriculture and grazing, although the abandonment of traditional mountain agriculture has produced a natural forest recovery in many regions of the world. The physical changes imposed on the landscape by the development of secondary woodland have brought both positive and negative consequences, depending on the geographical and economic context and on the scale of the sites. Among the ecological problems caused by natural reforestation, one of great interest is the reduction of open spaces resulting in a loss of landscape heterogeneity and mosaic features. This review paper focused its attention on landscape metrics or indices that are frequently used to assess the structural characteristics of the landscape and to monitor changes in land use: mean patch size (MPS), connectivity (CONN), boundary length (BL) and the patch number (NP). Through the analysis of 52 selected papers and 53 case studies, we identified the main gaps in current knowledge, providing directions for further research. Most of the reviewed studies focused only on a portion of the spatial attributes that we were interested in and only 32 case studies reported accurate data both on forest expansion rate and time range analyzed in the study area. We conclude that the study of changes in all the spatial attributes considered within the same case study is a key to explain ecological consequences in mosaic cycles or in stochastic dynamic landscapes that emerged from the interplay of several processes, and to predict and explain their spatial and temporal characteristics. The current knowledge of how changing spatial attributes affect biodiversity, habitats, and ecosystem functions is limited by the scarcity of studies that explicitly consider the shifting in time of the four spatial attributes together.
Myricaria germanica (L.) Desv. (German tamarisk) is an integral part of the ecological dynamics o... more Myricaria germanica (L.) Desv. (German tamarisk) is an integral part of the ecological dynamics of non-regulated rivers, which are characterized by annual flooding, and low water levels in summer. During the last century damming and regulation have interrupted the original riparian dynamics, reducing the German tamarisk natural habitats. The species is endangered in the Trentino region and its distribution is concentrated along the Avisio river, where the main habitats are grave and sandy banks. This work describes the last remaining populations of Myricaria germanica in the Trentino region.
The maggenghi are mid slope meadows typical of all the southern and of great parts of the norther... more The maggenghi are mid slope meadows typical of all the southern and of great parts of the northern European Alps, for centuries managed with traditional and low intensity techniques. Usually, they are scattered patches in surrounding forests. The spontaneous expansion of trees and shrubs, favored by the recent decline of mountain agriculture, lead the maggengo patches patterns and shapes to change. Our objective was to analyze the effect of this change on current plant diversity of the remnant patches, as the adaptive response could be slow and possibly related more to historical than to current landscape patterns. We analyzed the trend of the size, shape, elongation, fractal dimension and connectivity of maggengo patches of a Central-Eastern Italian Alpine district, in four time steps, from 1973 to 2006, and in 1859, when mountain agriculture was still widespread. Then, we studied the relationships between those landscape metrics and two current patch-level plant diversity measures: interior species richness and species density. Aerial photographs were used to investigate that trend, while a historical cadastral map was used to assess the landscape metrics in 1859. As expected, in the last 30 years, the total size of maggenghi has been reduced by 57% while their shapes have been progressively simplified. Interior species richness was positively related to size, both in 2006 and over the past 30 years, but not to any 1859 measures. Conversely, species density was positively correlated only with 1859 size, shape index and connectivity. We conclude that the historical shape, size and connectivity are some of the key variables affecting the plant species density of maggengo patches, but not of their interior plant species richness.
In: Research on the natural heritage of the Reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conservervation of two protected areas in the context of a LIFE Project. Quaderni Conservazione Habitat, 5 . Arti Grafiche Fiorini, Verona, pp. 35-44. ISBN 978-88-87082-98-2
In this paper we describe the vegetation of Vincheto di Celarda Nature Reserve based on our map o... more In this paper we describe the vegetation of Vincheto di Celarda Nature Reserve based on our map of the Natura 2000 Habitats which was created during the LIFE Project LIFE04NAT/IT/000190. The vegetation types with the highest nature value are the riparian woods (Salicion albae), and the communities on riverside gravel bars (Salicetum eleagni and Saturejon subspicatae - Scorzoneretalia community). We provide a physiognomic description of the vegetation which will be useful for the management of the reserve. The syntaxonomic aspects are described briefly.
Un libro per conoscere l'ecologia e la gestione dei boschi di neoformazione delle Alpi, con parti... more Un libro per conoscere l'ecologia e la gestione dei boschi di neoformazione delle Alpi, con particolare riferimento al Trentino, utile a ricercatori, studenti universitari ed esperti nella gestione delle foreste e del paesaggio rurale e peri-urbano. Dopo l'analisi storica delle foreste trentine e delle dinamiche socio-economiche ad esse collegate, vengono descritti i modi e i tempi che caratterizzano le successioni secondarie. Il terzo e quarto capitolo sono dedicati al metodo di rilevamento e alle caratteristiche generali che questi boschi assumono in Trentino. Il quinto capitolo è dedicato alla loro tipologia, ai trattamenti, compresi i miglioramenti ambientali, e alle dinamiche specifiche dei singoli tipi neoforestali. L'ultimo capitolo affronta la gestione e la pianificazione dal punto di vista del paesaggio in abbandono colturale, nell'ottica di conservazione della biodiversità, non trascurando l'eventualità di ricorrere alle trasformazioni di coltura. Concludono la trattazione una chiave di riconoscimento e 14 schede ricche di dati sintetici relativi a caratteri tipici dei boschi di recente insediamento. Disegni, schemi e fotografie arricchiscono la veste grafica del volume e contribuiscono a descrivere tecniche di gestione e caratteri ecologici.
This book focuses on the features and processes of the recent secondary forests of the Alps, where human and former land use influence is thought to be high, with special emphasis on a central-eastern Italian region (Trento Province). After an historical analysis of the forest changes and their socio-economical driving forces, the author discusses the temporal and spatial patterns of secondary successions leading to the formation of secondary woodlands. The third and fourth chapters deal with the survey method and the general characteristics of these woodlands in the Trento Province. The fifth chapter contains the classification, treatments, including restoration ecology, and dynamics associated to each neo-forest type. The last chapter is concerned with the management actions and planning approaches from the point of view of the abandoned rural and suburban landscapes. Biodiversity concerns, including the opportunities and risks related to forest conversion to the former land use, are outlined. There then follow a dichotomic key for the on-field identification of the neo-forest type and 14 sheets, where many data concerning attributes typical of recent secondary woodlands are reported. Pictures, diagrams and photographs help the reader understand management techniques and ecological characters.
Spatial patterns of vegetation arise from an interplay of functional traits, environmental charac... more Spatial patterns of vegetation arise from an interplay of functional traits, environmental characteristics and chance. The retreat of glaciers offers exposed substrates which are colonised by plants forming distinct patchy patterns. The aim of this study was to unravel whether patch-level landscape metrics of plants can be treated as functional traits. We sampled 46 plots, each 1 m × 1 m, distributed along a restricted range of terrain age and topsoil texture on the foreland of the Nardis glacier, located in the SouthEastern Alps, Italy. Nine quantitative functional traits were selected for 16 of the plant species present, and seven landscape metrics were measured to describe the spatial arrangement of the plant species' patches on the study plots, at a resolution of 1 cm × 1 cm. We studied the relationships among plant communities, landscape metrics, terrain age and topsoil texture. RLQ-analysis was used to examine trait-spatial configuration relationships. To assess the effect of terrain age and topsoil texture variation on trait performance, we applied a partial-RLQ analysis approach. Finally, we used the fourth-corner statistic to quantify and test relationships between traits, landscape metrics and RLQ axes. Floristically-defined relevé clusters differed significantly with regard to several landscape metrics. Diversity in patch types and size increased and patch size decreased with increasing canopy height, leaf size and weight. Moreover, more compact patch shapes were correlated with an increased capacity for the conservation of nutrients in leaves. Neither plant species composition nor any of the landscape metrics were found to differ amongst the three classes of terrain age or topsoil texture. We conclude that patch-level landscape metrics of plants can be treated as species-specific functional traits. We recommend that existing databases of functional traits should incorporate these type of data.
The species richness of hedges in an agricultural landscape may be determined by the environment ... more The species richness of hedges in an agricultural landscape may be determined by the environment and by the spatial processes which occur in that landscape. Here, we divided the environmental predictors into three groups: site conditions, hedge stand and landscape structure. We determined their independent and joint effects on the richness of four guilds of herbaceous species in 92 hedge stands in a north-Mediterranean intensive agricultural landscape. The fine—(at <250 m) and broad—(>550 m) spatial patterns of the key environmental predictors and the pure spatial effects on species richness were measured using a computation of the principal coordinates of a matrix of geographical neighbours integrated into a variation partitioning. The total explained variation of species richness among hedgerows was highest for wetland herbs (62 %), with increasing rates for rare plants (33 %), forest herbs (43 %) and arable weeds (47 %). 43–11 % of that variation was spatially structured and mostly explained by some of the key environmental predictors, such as proportion of a given landuse, presence of woody species and dead trees. This indicates that complex relationships between herbaceous species distribution and spatial processes exist in woody field margins and much of that is related to key factors which are spatially structured, both at fine or broad-scales, with implications for management and landuse planning.
The effectiveness of conservation interventions for maximizing biodiversity benefits from agri-en... more The effectiveness of conservation interventions for maximizing biodiversity benefits from agri-environment schemes (AESs) is expected to depend on the quantity of seminatural habitats in the surrounding landscape. To verify this hypothesis, we developed a hierarchical sampling design to assess the effects of field boundary type and cover of seminatural habitats in the landscape at two nested spatial scales. We sampled three types of field boundaries with increasing structural complexity (grass margin, simple hedgerow, complex hedgerow) in paired landscapes with the presence or absence of seminatural habitats (radius 0.5 km), that in turn, were nested within 15 areas with different proportions of seminatural habitats at a larger spatial scale (10 X 10 km). Overall, 90 field boundaries were sampled across a Mediterranean&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;region (northeastern Italy). We considered species richness response across three different taxonomic groups: vascular plants, butterflies, and tachinid flies. No interactions between type of field boundary and surrounding landscape were found at either 0.5 and 10 km, indicating that the quality of field boundary had the same effect irrespective of the cover of seminatural habitats. At the local scale, extended-width grass margins yielded higher plant species richness, while hedgerows yielded higher species richness of butterflies and tachinids. At the 0.5-km landscape scale, the effect of the proportion of seminatural habitats was neutral for plants and tachinids, while butterflies were positively related to the proportion of forest. At the 10-km landscape scale, only butterflies responded positively to the proportion of seminatural habitats. Our study confirmed the importance of testing multiple scales when considering species from different taxa and with different mobility. We showed that the quality of field boundaries at the local scale was an important factor in enhancing farmland biodiversity. For butterflies, AESs should focus particular attention on preservation&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;of forest patches in agricultural landscapes within 0.5 kin, as well as the conservation of seminatural habitats at a wider landscape scale.
Potential forest-related information which can be obtained from processing laser scanner data mak... more Potential forest-related information which can be obtained from processing laser scanner data make this technology extremely useful for management and assessment of forests. It is thoroughly documented in recent literature how specific forest characteristics can be estimated at stand, plot and single tree level using laser scanner surveys at corresponding scales. The high resolution models of the canopy surface and of the bare earth (terrain), and also the information obtained of the structure of the volume between ...
Research on changes in biodiversity due to the abandonment of forestry is important in understand... more Research on changes in biodiversity due to the abandonment of forestry is important in understanding the role of reserves in conservation. The aim of this study was to investigate whether changes have occurred in species richness, abundance and composition of ground, longhorn and bark beetles due to habitat changes as a result of the cessation of forest management. We surveyed ten managed and ten abandoned forest plots in two watersheds located in the north-eastern Italian alpine region, which share a common history of use, climate regimes, stand structure and topography. Ground beetles, and longhorn and bark beetles were collected with pitfall and flight-intercept window traps, respectively, from May to mid-October 2010. The three beetle taxa responded differently to changes in habitat features and management cessation. Differences in individual species responses between the two watersheds may indicate a role of management abandonment through its impact on forest habitat structure. For instance, ground beetle species mainly responded negatively to soil moisture and positively to understorey vegetation cover. Unexpectedly, saproxylic species re- sponded variably, and often negatively, to deadwood fea- tures in these forests, but did respond positively to the volume of standing Abies alba trees. The assemblages of carabids and bark beetles differed between the two water- sheds. Our results confirmed that 50 years of forest man- agement cessation resulted in changes in the biodiversity of beetles in alpine forests, likely due to their response to changes in habitat structure. Moreover, we expect that where the unplanned abandonment of forestry practices and habitat rewilding are undergoing, like in many mar- ginal areas of Europe, similar habitat structure dynamics and beetle responses are likely to occur spontaneously.
A new field of forestry science is required to assume the responsibilities that a new European re... more A new field of forestry science is required to assume the responsibilities that a new European regulation will give to Member States. Are silviculturists ready to share and improve scientific knowledge on the management of invasive tree species alien to Europe?
The objective of this study was to investigate a grid-based sampling design to determine the cros... more The objective of this study was to investigate a grid-based sampling design to determine the cross-scalar selection of habitat by a territorial animal species: the hazel grouse (Tetrastes bonasia L.). In each of three sites with increasing hazel grouse nest site density, three lattice grids were used to measure both the habitat variables and the species occurrence in 100 30 × 30 m cells. We calculated the average values for habitat variables, as well as use versus non-use by the species, at three spatial scales: small (1 × 1 cell), intermediate (2 × 2 cells) and large (3 × 3 cells). Generalised linear mixed models were integrated into a method of variation and hierarchical partitioning and used to assess the relationship between the habitat variables and the species preferences at each scale. In all scales, species selection was associated with ground layer composition. Selection was also associated with the composition of the woody layer and negatively associated with dominance of tor grass (Brachypodium rupestre (Host) Roem. & Schult.) at the two larger scales. Both litter cover and thinning contributed positively to the habitat selection at the two smaller scales. The other variables were significant only at one scale or explained a relatively low proportion of the variation at multiple scales. Neither the management nor the stand structure variables played a significant independent role across scales when compared with ground layer variables. The total variation explained was highest (ca. 90 %) at the large scale. This finding indicates the possibility of obtaining cross-scalar hazel grouse preferences from grid-based sampling, provided that spatial autocorrelation in the data is handled appropriately.
The woody component along field edges often provides the only permanent elements of structural an... more The woody component along field edges often provides the only permanent elements of structural and biological diversity in landscapes that have lost much of their naturalness to agriculture and urban use. The main aims of this study were (i) to investigate how four hedge stand types, i.e., systems of management distinguished on the basis of the natural and managed growth forms of trees and shrubs (low single-storied, high single-storied, two-storied and multi-storied), differ in their biometric parameters and (ii) to identify the primary management-related determinants of native woody species richness. The study used a large dataset of hedgerows (n=538) sampled in seven sites in Northern Italy. The four hedge stand types exhibited highly significant differences in size and biometric parameters. The multi-storied hedges, associated with the highest stand structural diversity index values, supported the highest number of tree species, followed by high single-storied hedges. The low single-storied hedge stand type contained the lowest number of species. We found a positive effect of hedge area as well as a marginal negative effect of basal area on native woody species richness. The management implications addressed by our study include conversion of single-storied into two- or multi-storied types, increasing hedge size and controlling hedge stand basal area
Although few undisturbed forests remain in Europe, forest reserves and deforested areas that are ... more Although few undisturbed forests remain in Europe, forest reserves and deforested areas that are no longer profitable have the potential to develop stand structures similar to those which preceded human disturbances. The direct effects of management cessation on forest diversity are confounded by many factors that should be controlled when comparing managed and abandoned stands. In the European Alps, however, the high variability of habitats makes it nearly impossible to find comparable stands located within forests large enough to be independent from the surrounding land. The aim of this study was to investigate the use of mixed models to compare deadwood and plant diversity between matched managed and unmanaged pairs of forests, with the hypothesis that their differences were due to direct effect of abandonment. Two neighbouring watersheds that were large enough to be independent from the surrounding forests were chosen. These watersheds had a common history of use, but one was non-intensively managed, while the other was untouched since 1957. Ten plots were randomly selected from each forest. Mixed models confirmed their matched topography and stand structure, while a similarity index confirmed their assignment to the same plant community. The unmanaged stand had higher soil nitrogen, higher Fagus sylvatica dendrological composition, higher tree species richness, higher dead logs and a different composition of the tree and understory layers. These results suggest that silver fir woodlands abandoned for more than 50years change spontaneously and that this approach may be an effective means for studying other forest communities.
Black locust (Robinia pseudoacacia L.) is a widespread alien tree species commonly thought to inf... more Black locust (Robinia pseudoacacia L.) is a widespread alien tree species commonly thought to influence plant assemblages. The aim of this study was to compare the plant diversity between black locust and native recent secondary stands within the European Mediterranean Mountains environmental zone. Spontaneous reforestation was detected by comparing historical aerial photographs and the most recent images. Distributed throughout a 2700 km2 hilly and piedmont area, 32 black locust and 32 paired native stands were selected and all vascular plant species were surveyed in a 100 m2 area. Analyses of the α and β-diversity were performed separately for six identified plant groups. Despite a clear difference in the tree diversity between the black locust and native recent secondary stands and a homogenisation of the tree layer by the black locust stands, we found only inconsistent hints for homogenisation of the ground-layer vegetation by the black locust stands. There is no evidence to suggest that the presence of black locust in recent secondary stands plays a major role in shaping the diversity of the understory plant groups compared to native stands.
In the Alps, many forests are under abandonment because of direct protection or the unprofitabili... more In the Alps, many forests are under abandonment because of direct protection or the unprofitability of timber production. The objective of this study was to analyse the effect of silviculture abandonment on the species richness and composition of epiphytic and dead wood-dwelling lichens in silver fir woodlands. An abandoned and a currently non-intensively managed forest watershed of the eastern Italian Alps that were matched for topography, stand structure, plant community and history of use were selected and randomly sampled for the lichen diversity of their silver fir mature stands. Generalised linear mixed models were used for the analyses of the species richness, whereas the species composition patterns were explored by redundancy analysis. The diversity of both of the lichen guilds were explained by the microhabitat conditions related to the contrasting management regimes, but they had opposite responses to the abandonment of the silvicultural activities. The epiphytic lichen communities were richer in species in the managed than in the abandoned silver fir woodlands. However, the effect of a 50 year management cessation on the epiphytic lichens may change in the long term when natural disturbances create gaps and increase the attributes of old-growth forests. The dead wood-dwelling lichen species richness was higher in the abandoned forest because an increased availability of types of dead wood is usually rare in managed forests. The dead wood-dwelling lichen communities of the managed forests were a subset of a more diverse community that was developing in the abandoned forest. Our results indicated that, in non-intensively managed silver fir mature stands, lichen diversity may benefit from the retention of logs and snags, which provide habitat features typical of old-growth forests.
In: Hedgerow Futures, edited by John Dover, pp. 135-146, 2012
Here we summarise the findings of a study investigating the environmental, management, and land u... more Here we summarise the findings of a study investigating the environmental, management, and land use factors that influence patterns of biodiversity in field margins in the Po Plain, Italy, and evaluate these habitats for their cultural and biodiversity value. We highlight four traditional management techniques of woody vegetation in field margins on the Po Plain, Italy, and make recommendations for further study to investigate the ecosystem services and cultural significance of these features
Through the classification of current and historical aerial photos between 1973 and 2006, we anal... more Through the classification of current and historical aerial photos between 1973 and 2006, we analysed the evolution of size, shape and connectivity of 59 mountain meadows (maggenghi) of the Pejo di- strict (Trentino, Northern Italy). The maggenghi are scattered patches within a forested matrix. We conducted the same analysis on an Austro-Hungarian cadastral map of 1859. The total surface covered by maggenghi was 137.4 ha in 1973, and decreased to 78.3 ha (57%) in 2006. The mean shape and connectivity index in 1973 are significantly lower than those of 2006. Within a 1-km radius around the studied patches, woodlands in- creased by 7% in the same time range. Among the 25 maggenghi present in 1958, 12 has been subdivided into 39 smaller fragments and 13 has been reduced in their size without any fragmentation. A general process of meadow patches evolution which included area and connectivity reduction and shape simplification has been noticed. This process is common to many other alpine landscapes. The study of these processes is fundamental for policies aimed to conservation of mountain meadows, as well as to identify the single patches deserving conservation for their current and historical landscape structure, as many studies report their significant effects on local floristic diversity.
Potential forest-related information can be obtained from processing data obtained from laser sca... more Potential forest-related information can be obtained from processing data obtained from laser scanning sensors making this technology extremely useful for forest management and
environmental assessment. It is thoroughly documented in recent literature how specific forest characteristics can be estimated at stand, plot and single tree level using laser scanner surveys at corresponding scales. The high resolution models of the canopy surface and of the bare earth (terrain), as well as the information obtained related to the structure of the volume between these two surfaces, concur at offering a more complete source of information not only for direct forestry-related applications, but also for connected disciplines such as hydrology, engineering, forest disturbances analysis and ecological assessment.
Having accurate and spatially distributed information over the above mentioned aspects give land assessment and management added value data to work with. Correct utilization
of laser scanner data can lead to the assessment of many characteristics usually obtained by ground surveys. Ground-plots require significant expenditure in terms of human effort,
economical investment and can be distributed on large areas only in limited number. The following paper shows the efforts which are being undertaken by scientific research towards testing laser scanner applications for forest and environmental sciences
The present landscape structure and function is the result of centuries of changes produced both ... more The present landscape structure and function is the result of centuries of changes produced both by natural processes and human driving forces. For centuries many mountain and hillside areas have been the subject of deforestation to create space for agriculture and grazing, although the abandonment of traditional mountain agriculture has produced a natural forest recovery in many regions of the world. The physical changes imposed on the landscape by the development of secondary woodland have brought both positive and negative consequences, depending on the geographical and economic context and on the scale of the sites. Among the ecological problems caused by natural reforestation, one of great interest is the reduction of open spaces resulting in a loss of landscape heterogeneity and mosaic features. This review paper focused its attention on landscape metrics or indices that are frequently used to assess the structural characteristics of the landscape and to monitor changes in land use: mean patch size (MPS), connectivity (CONN), boundary length (BL) and the patch number (NP). Through the analysis of 52 selected papers and 53 case studies, we identified the main gaps in current knowledge, providing directions for further research. Most of the reviewed studies focused only on a portion of the spatial attributes that we were interested in and only 32 case studies reported accurate data both on forest expansion rate and time range analyzed in the study area. We conclude that the study of changes in all the spatial attributes considered within the same case study is a key to explain ecological consequences in mosaic cycles or in stochastic dynamic landscapes that emerged from the interplay of several processes, and to predict and explain their spatial and temporal characteristics. The current knowledge of how changing spatial attributes affect biodiversity, habitats, and ecosystem functions is limited by the scarcity of studies that explicitly consider the shifting in time of the four spatial attributes together.
Myricaria germanica (L.) Desv. (German tamarisk) is an integral part of the ecological dynamics o... more Myricaria germanica (L.) Desv. (German tamarisk) is an integral part of the ecological dynamics of non-regulated rivers, which are characterized by annual flooding, and low water levels in summer. During the last century damming and regulation have interrupted the original riparian dynamics, reducing the German tamarisk natural habitats. The species is endangered in the Trentino region and its distribution is concentrated along the Avisio river, where the main habitats are grave and sandy banks. This work describes the last remaining populations of Myricaria germanica in the Trentino region.
The maggenghi are mid slope meadows typical of all the southern and of great parts of the norther... more The maggenghi are mid slope meadows typical of all the southern and of great parts of the northern European Alps, for centuries managed with traditional and low intensity techniques. Usually, they are scattered patches in surrounding forests. The spontaneous expansion of trees and shrubs, favored by the recent decline of mountain agriculture, lead the maggengo patches patterns and shapes to change. Our objective was to analyze the effect of this change on current plant diversity of the remnant patches, as the adaptive response could be slow and possibly related more to historical than to current landscape patterns. We analyzed the trend of the size, shape, elongation, fractal dimension and connectivity of maggengo patches of a Central-Eastern Italian Alpine district, in four time steps, from 1973 to 2006, and in 1859, when mountain agriculture was still widespread. Then, we studied the relationships between those landscape metrics and two current patch-level plant diversity measures: interior species richness and species density. Aerial photographs were used to investigate that trend, while a historical cadastral map was used to assess the landscape metrics in 1859. As expected, in the last 30 years, the total size of maggenghi has been reduced by 57% while their shapes have been progressively simplified. Interior species richness was positively related to size, both in 2006 and over the past 30 years, but not to any 1859 measures. Conversely, species density was positively correlated only with 1859 size, shape index and connectivity. We conclude that the historical shape, size and connectivity are some of the key variables affecting the plant species density of maggengo patches, but not of their interior plant species richness.
In: Research on the natural heritage of the Reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conservervation of two protected areas in the context of a LIFE Project. Quaderni Conservazione Habitat, 5 . Arti Grafiche Fiorini, Verona, pp. 35-44. ISBN 978-88-87082-98-2
In this paper we describe the vegetation of Vincheto di Celarda Nature Reserve based on our map o... more In this paper we describe the vegetation of Vincheto di Celarda Nature Reserve based on our map of the Natura 2000 Habitats which was created during the LIFE Project LIFE04NAT/IT/000190. The vegetation types with the highest nature value are the riparian woods (Salicion albae), and the communities on riverside gravel bars (Salicetum eleagni and Saturejon subspicatae - Scorzoneretalia community). We provide a physiognomic description of the vegetation which will be useful for the management of the reserve. The syntaxonomic aspects are described briefly.
In: Research on the natural heritage of the Reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conservation of two protected areas in the context of a LIFE project. Quaderni Conservazione Habitat, 5 . Arti Grafiche Fiorini, Verona, pp. 325-334. ISBN 978-88-87082-98-2, 2008
"The vegetation of Val Tovanella Nature Reserve was surveyed during the LIFE Project LIFE04NAT/IT... more "The vegetation of Val Tovanella Nature Reserve was surveyed during the LIFE Project LIFE04NAT/IT/000190 to produce a map of Habitats of Community interest (Natura 2000 Habitats). The territory of the reserve is mostly occupied by forests, and a large number of forest types and their respective facies were recorded. Particularly important are Tilio-Acerion ravine forests, and black pine forests, which are Priority Habitat types. The forest cover includes wide silver fir and beech forests, and the subalpine mountain pine woods, the latter being a Priority Habitat type as well. Pioneer vegetation of the rocky slopes and screes is well-represented. We present the list and a description of habitat types, which are essential for future management, and we also highlight the nature value of the vegetation, with regard to syntaxonomic features.
"
Speech on behalf of the research scientists of the Padova University courses of studies in forest... more Speech on behalf of the research scientists of the Padova University courses of studies in forest and environmental sciences
Uploads
Books by Tommaso Sitzia
This book focuses on the features and processes of the recent secondary forests of the Alps, where human and former land use influence is thought to be high, with special emphasis on a central-eastern Italian region (Trento Province). After an historical analysis of the forest changes and their socio-economical driving forces, the author discusses the temporal and spatial patterns of secondary successions leading to the formation of secondary woodlands. The third and fourth chapters deal with the survey method and the general characteristics of these woodlands in the Trento Province. The fifth chapter contains the classification, treatments, including restoration ecology, and dynamics associated to each neo-forest type. The last chapter is concerned with the management actions and planning approaches from the point of view of the abandoned rural and suburban landscapes. Biodiversity concerns, including the opportunities and risks related to forest conversion to the former land use, are outlined. There then follow a dichotomic key for the on-field identification of the neo-forest type and 14 sheets, where many data concerning attributes typical of recent secondary woodlands are reported. Pictures, diagrams and photographs help the reader understand management techniques and ecological characters.
Papers by Tommaso Sitzia
environmental assessment. It is thoroughly documented in recent literature how specific forest characteristics can be estimated at stand, plot and single tree level using laser scanner surveys at corresponding scales. The high resolution models of the canopy surface and of the bare earth (terrain), as well as the information obtained related to the structure of the volume between these two surfaces, concur at offering a more complete source of information not only for direct forestry-related applications, but also for connected disciplines such as hydrology, engineering, forest disturbances analysis and ecological assessment.
Having accurate and spatially distributed information over the above mentioned aspects give land assessment and management added value data to work with. Correct utilization
of laser scanner data can lead to the assessment of many characteristics usually obtained by ground surveys. Ground-plots require significant expenditure in terms of human effort,
economical investment and can be distributed on large areas only in limited number. The following paper shows the efforts which are being undertaken by scientific research towards testing laser scanner applications for forest and environmental sciences
This book focuses on the features and processes of the recent secondary forests of the Alps, where human and former land use influence is thought to be high, with special emphasis on a central-eastern Italian region (Trento Province). After an historical analysis of the forest changes and their socio-economical driving forces, the author discusses the temporal and spatial patterns of secondary successions leading to the formation of secondary woodlands. The third and fourth chapters deal with the survey method and the general characteristics of these woodlands in the Trento Province. The fifth chapter contains the classification, treatments, including restoration ecology, and dynamics associated to each neo-forest type. The last chapter is concerned with the management actions and planning approaches from the point of view of the abandoned rural and suburban landscapes. Biodiversity concerns, including the opportunities and risks related to forest conversion to the former land use, are outlined. There then follow a dichotomic key for the on-field identification of the neo-forest type and 14 sheets, where many data concerning attributes typical of recent secondary woodlands are reported. Pictures, diagrams and photographs help the reader understand management techniques and ecological characters.
environmental assessment. It is thoroughly documented in recent literature how specific forest characteristics can be estimated at stand, plot and single tree level using laser scanner surveys at corresponding scales. The high resolution models of the canopy surface and of the bare earth (terrain), as well as the information obtained related to the structure of the volume between these two surfaces, concur at offering a more complete source of information not only for direct forestry-related applications, but also for connected disciplines such as hydrology, engineering, forest disturbances analysis and ecological assessment.
Having accurate and spatially distributed information over the above mentioned aspects give land assessment and management added value data to work with. Correct utilization
of laser scanner data can lead to the assessment of many characteristics usually obtained by ground surveys. Ground-plots require significant expenditure in terms of human effort,
economical investment and can be distributed on large areas only in limited number. The following paper shows the efforts which are being undertaken by scientific research towards testing laser scanner applications for forest and environmental sciences
"