The predicted increasing atmospheric carbon dioxide (CO2) level is responsive to altering the future climate, and a small change in the soil carbon may significantly affect the forest carbon cycle and climate system. Soil respiration (SR)... more
The predicted increasing atmospheric carbon dioxide (CO2) level is responsive to altering the future climate, and a small change in the soil carbon may significantly affect the forest carbon cycle and climate system. Soil respiration (SR) and its influencing factors like soil temperature (ST), soil water content (SWC) and surface litter-fall were measured monthly over one year in a sub-tropical Pine (Pinus roxburghii) forest of Bhaktapur district located in central Nepal to determine the SR of the forest and, its variations and sensitivity. The results showed that SR varied to the changes in ST by an exponential significant positive correlation between them. The optimum SR was observed between 10 and 22ºC, and the highest SR were obtained above ST at 20ºC. The temperature sensitivity value of SR (Q10) was estimated at Q10 = 2.13. The significant exponential curve represented the effect of SWC on SR. The higher SR rate was mostly measured between 10 and 25% SWC. The monthly and seaso...
Research Interests:
Research Interests:
Parthenium hysterophorus is a noxious invasive alien weed distributed in agroecosystems. This weed shows phytotoxic properties on other plants in the invaded areas. This study aims to evaluate the phytotoxic effects of this weed on seed... more
Parthenium hysterophorus is a noxious invasive alien weed distributed in agroecosystems. This weed shows phytotoxic properties on other plants in the invaded areas. This study aims to evaluate the phytotoxic effects of this weed on seed germination, seedling growth and development of wheat (Triticum aestivum) with petri plate and pot experiments. Seeds and seedlings of wheat were treated with P. hysterophorus leaf leachates extracted using more natural way i.e., by soaking the leaves in water rather crushing or powdering. Results show that the leachates of P. hysterophorus exhibits negative effects on seed germination and growth parameters of wheat in petri plate experiment. The phytotoxic effects of leachates on rootshoot length and shoot biomass was not were not significant in the pot experiment. Therefore, actual concentration of leachates that start hindrance to the recipient plants varies between the petri plate and pot bioassays. Further studies to understand the leachate inte...
Research Interests:
Societal Impact StatementPlant–pollinator relationships are fundamentally important for the conservation of the terrestrial biodiversity that rural communities in low‐income countries rely upon. In Nepal, a country that is biologically... more
Societal Impact StatementPlant–pollinator relationships are fundamentally important for the conservation of the terrestrial biodiversity that rural communities in low‐income countries rely upon. In Nepal, a country that is biologically rich but economically poor, Rhododendron forests provide a range of ecosystem services that are under threat from overexploitation and climate change. Here, we suggest a vital role for pollinating birds in ensuring the sexual reproduction, and thus the long‐term survival, of Rhododendron populations. In this respect, the pollinators are an important link between people and the plants on which they depend. However, we also highlight how little we know about these interactions, with significant knowledge gaps for even the most basic aspects of their ecology.
Research Interests:
Research Interests:
Increased human pressure and urbanization has led into the formation of forest islands in the Kathmandu valley. Bhandarkhal forest (area: 6.75 ha), situated in the eastern part of Pashupati area represents a typical such forest Kathmandu.... more
Increased human pressure and urbanization has led into the formation of forest islands in the Kathmandu valley. Bhandarkhal forest (area: 6.75 ha), situated in the eastern part of Pashupati area represents a typical such forest Kathmandu. The sandy loam soil in the forest is described as characteristic of lacustrine sediments. The soil was slightly acidic with pH 5.4, and contained organic matter 6.3%, nitrogen 0.29%, phosphorous 821 kg/ha, and potassium 1171 kg/ha. Over 35 species were recorded at the tree stratum (>4m height). The most frequently seen trees at the stratum were Zizyphus incurva , Stralzvaesia nussia , Ilex excelsa and Persea duthiei . At the shrub stratum (1-4m height), the most frequently occurring shrub species were Clredertdron viscosum , Sarcococca coriacea , Xylosma controversum and Murraya exotica . The ground coverage of the forest was above 70% in average except in some few places. The most frequently occurring species at the ground stratum (<1 m heig...
Research Interests:
Urban forest ecosystems, the structure and functions therein, are subjected to anthropogenic disturbances. Native and sensitive species from those forests might be lost due to such disturbances. At the same time, supplemented... more
Urban forest ecosystems, the structure and functions therein, are subjected to anthropogenic disturbances. Native and sensitive species from those forests might be lost due to such disturbances. At the same time, supplemented anthropogenic resources might create opportunities for exotic and invasive species. Although, invasive species are considered as one of the major threats to the urban biodiversity and ecosystems, the researches on invasion dynamics in the Himalayas have mostly focused on the impacts of invasion on forest structure and productivity. This study aims to understand the influence of forest structure and anthropogenic factors in invasion success that are poorly covered in the existing literature. We selected 11 urban forest patches for the study considering the presence-absence of selected invasive species and structural attributes. We used Principal Component Analysis (PCA) to reduce co-linearity in the covariates and generalized linear mixed effects model (GLMM) to...
Research Interests:
Rising atmospheric CO2 and temperature are altering ecosystems’ carbon cycle. Soil respiration is a potential natural source of atmospheric CO2, an important terrestrial process to characterize soil as a carbon source or sink. Research... more
Rising atmospheric CO2 and temperature are altering ecosystems’ carbon cycle. Soil respiration is a potential natural source of atmospheric CO2, an important terrestrial process to characterize soil as a carbon source or sink. Research carried was out in Annapurna Conservation Area (ACAP) as climate change poses special problems for mountain protected areas. Nepal has targeted to reduce the emissions resulting from land-use change by enhancing forest carbon stock by 5% above the 2015 level within 2025. In this case, identifying, quantifying and addressing different potential emission sources are very important. Soil respiration is the process of measuring natural carbon emissions from soil. The study in ACAP soil carbon emission from the forest, grassland, and agricultural lands was investigated using the close chamber method. The global temperature rise has been set to a global 2°C below the preindustrial period by the IPCC. The rise in temperature has a positive feedback response ...
Research Interests:
Prevailing climate change is expected due to carbon dioxide emission to the atmosphere through soil respiration and perhaps the alteration in the terrestrial carbon cycle. The measurements to establish the effect and sensitivity of soil... more
Prevailing climate change is expected due to carbon dioxide emission to the atmosphere through soil respiration and perhaps the alteration in the terrestrial carbon cycle. The measurements to establish the effect and sensitivity of soil temperature, soil water content and plant biomass on soil respiration was performed in the sub-tropical grassland located in Central Nepal. Field measurements of soil respiration was conducted by using the closed-chamber method, and soil temperature, soil water content and plant biomass were monitored in the years 2015 and 2016. The soil respiration showed positive significant exponential function which accounted for 74.6% (R2=0.746, p<0.05) of its variation with the soil temperature. The temperature sensitivity of soil respiration, Q10 value obtained was 2.68. Similarly, soil respiration showed a positive significant exponential function that accounted for 37.2% (R2=0.372, p<0.05) of its variation with the soil water content. Remarkable season...
Research Interests:
ASSESSMENT OF CARBON STOCK IN GOKARNA FOREST, KATHMANDU, NEPAL Sagar Dhakal*, Sanu Raja Maharjan, Prakash C Aryal *Correspondence: sagardhakal2043@gmail.com 1 Department of Environmental Science, GoldenGate International College,... more
ASSESSMENT OF CARBON STOCK IN GOKARNA FOREST, KATHMANDU, NEPAL Sagar Dhakal*, Sanu Raja Maharjan, Prakash C Aryal *Correspondence: sagardhakal2043@gmail.com 1 Department of Environmental Science, GoldenGate International College, Kathmandu, Nepal Abstract Assessment of carbon stock in urban forest is essential to obtain the carbon sequestration rate and has important role in urban environment with play vital role to conserve biodiversity. This study was conducted in Gokarna protected forest, Kathmandu, to explore the forest carbon stock. A total of 60 circular plots of random sample with size of 250 m were sampled for study. The biomass of standing trees was estimated by using allometric equation of trees, measuring their diameter & height. A total of 844 trees were measured belonging to 52 species. The total tree biomass was found to be 548.92t/ha. The aboveground tree carbon and belowground tree carbon were found 214.99 (t/ha) and 42.99 (t/ha) respectively. On the basis of IVI val...
The growth of urban population in Kathmandu has resulted in increased degradation of its forests and consequently increased recreational pressure on them. Ranibari forest (area 7.6 ha), situated at the north west region of Kathmandu... more
The growth of urban population in Kathmandu has resulted in increased degradation of its forests and consequently increased recreational pressure on them. Ranibari forest (area 7.6 ha), situated at the north west region of Kathmandu valley represents a typical such forest in Kathmandu. Quantitative study was carried to assess the structural dimensions and analyze community structure of the forest. Samplings were done in 26 large quadrats (size: 25mx25m) for canopy stratum, 52 medium plots (size: 5mx5m) for understory stratum and 130 small plots (size: 1mx1m) for the study of ground vegetation. The forest was floristically rich with a total of 108 species belonging to 58 families and 92 genera. The canopy stratum was predominated by dense clumps of bamboos and tree species of regional flora such as Zizyphus incurva, Stranvaesia nussia, Persea duthiei, Engelhardtia spicata, Celtis australis, and Schima wallichii. The shrub vegetation was relatively poor, dominated by invasive alien La...
Research Interests:
Non-Timber Forest Products (NTFPs) are the forest products except timber used for various purposes from which economic status of the country can be increased through green growth based economy. The study was conducted in Baghmara Buffer... more
Non-Timber Forest Products (NTFPs) are the forest products except timber used for various purposes from which economic status of the country can be increased through green growth based economy. The study was conducted in Baghmara Buffer Zone Community Forest for the inventory, to document various uses and find out the preferred NTFPs potential for economic development of Community Forest User Groups. Stratified random sampling was applied in which 50 quadrats of size 25m×20m for trees, 100 subplots of 10m×10m for shrubs and 200 small subplots of 1m×1msize for herbs and climbers were taken. Parameters like density, frequency, abundance, importance value index, diversity index, evenness index and dominance index were calculated to find out the ecological status of NTFPs. Questionnaire survey of 100 households was done for studying different uses and interview with 10 key informants were carried out to identify 10 most preferred NTFPs. Altogether, 109 NTFPs were enumerated. Trewia nudi...
Research Interests:
Research Interests:
The growth of urban population in Kathmandu has resulted in increased degradation of its forests and consequently increased recreational pressure on them. Ranibari forest (area 7.6 ha), situated at the north west region of Kathmandu... more
The growth of urban population in Kathmandu has resulted in increased degradation of its forests and consequently increased recreational pressure on them. Ranibari forest (area 7.6 ha), situated at the north west region of Kathmandu valley represents a typical such forest in Kathmandu. Quantitative study was carried to assess the structural dimensions and analyze community structure of the forest. Samplings were done in 26 large quadrats (size: 25mx25m) for canopy stratum, 52 medium plots (size: 5mx5m) for understory stratum and 130 small plots (size: 1mx1m) for the study of ground vegetation. The forest was floristically rich with a total of 108 species belonging to 58 families and 92 genera. The canopy stratum was predominated by dense clumps of bamboos and tree species of regional flora such as Zizyphus incurva, Stranvaesia nussia, Persea duthiei, Engelhardtia spicata, Celtis australis, and Schima wallichii. The shrub vegetation was relatively poor, dominated by invasive alien La...
Research Interests:
ABSTRACT With the increased loss of plant biodiversity, the Ex situ seed conservation has become of strategic importance. International treaties and conventions encourage more developed countries to cooperate in providing financial and... more
ABSTRACT With the increased loss of plant biodiversity, the Ex situ seed conservation has become of strategic importance. International treaties and conventions encourage more developed countries to cooperate in providing financial and other supports for the establishment and maintenance of Ex situ conservation facilities in developing countries. In this regard, the Nepal Academy of Science and Technology (Nepal) and the Ev-K2-CNR (Italy) set up the Himalayan Seed Bank, with the goal of establishing Ex situ seed conservation facility of rare, endemic and endangered plants in Nepal. Here, we discuss the importance of training on seed curation, management and research for the seed bank operators in developing countries. Particular attention is given to the procedures for providing power supply and for optimizing seed longevity in dry storage. Finally, the importance of duplicates in high-standard international seed banks is also discussed.
Research Interests:
Forests are the integral to the global carbon cycle. These ecosystems sequester carbon in the plant biomass and in the soil. The study was carried out in Linga Guthi Community Forest of Bhaktapur to estimate carbon Stock and radial growth... more
Forests are the integral to the global carbon cycle. These ecosystems sequester carbon in the plant biomass and in the soil. The study was carried out in Linga Guthi Community Forest of Bhaktapur to estimate carbon Stock and radial growth of Pinus roxburghii through tree ring analysis. A total of 32 circular plots of 250 m2 area were laid down randomly. Subplots were made for study of saplings, Litter, herbs and soil. For tree ring analysis, tree core samples were collected from different blocks of forest. Ring widths were measured using TSAP-Win Software attached to a LINTAB measuring system. For tree ring analysis, COFECHA and ARSTAN program were used. The average carbon stock of Linga Guthi Community Forest was 272.22±17.36 t/ha. Similarly, it has storage of 206.87± 4.47 t/ha AGTC, 41.37±2.19 t/ha BGTC, 23.814±1.00 t/ha SOC. The carbon sequestration rate of the forest was 2.22 Ct/ha/year. The average radial growth of pine trees in the forest was found to be 2.06 ± 0.13 mm/year. T...