Sailesh Ranjitkar | Kunming institute of Botany (original) (raw)

Papers by Sailesh Ranjitkar

Research paper thumbnail of Species distribution and ecological niche modelling of Alnus species in Nepal A Master Degree Dissertation, CDB, TU

Research paper thumbnail of Lu et al 2016.pdf

Research paper thumbnail of Research Article EFFECT OF ELEVATION AND LATITUDE ON SPRING PHENOLOGY OF

Mountainous terrain in the East corner of Nepal is a good location for phenological studies. Spri... more Mountainous terrain in the East corner of Nepal is a good location for phenological studies. Spring phenology in Rhododendron arboreum Sm. was monitored around the Ghunsa river valley in Kanchenjunga Conservation Area of Nepal. Observations were carried out following the crown density method; flowering events of the selected species were recorded in 15-days interval. Flowering activity including duration of flowering and synchrony were determined. In addition, expected difference in flower onset time in two consecutive monitoring plots was determined. Elevation, latitude and longitude were regressed against the flower onset to determine the effect of each variable on flower onset. Delay in flower onset along with rise in elevation, North latitude and West longitude was found in the results of the regression. Full bloom phase was found highly synchronized throughout the elevation gradient with contraction of flowering duration. High synchrony also indicates that the reproductive timi...

Research paper thumbnail of Reusing wasteroot of Rubia wallichiana dyeing from Monpa of Tibet in China

Scientific Reports, 2021

Humans have dyed textiles and leather, colored food, and paint body parts using natural dyes thro... more Humans have dyed textiles and leather, colored food, and paint body parts using natural dyes throughout history. Natural dyes have suffered drastically due to recent socioeconomic changes and replacement with synthetic dye in the textile industry. Hence, it is urgent to study indigenous dye plants and dyeing craft in local communities to protect these resources' potential ecological, economic, and cultural values. In 11 Monpa villages of Mêdog County, South-east Tibet, China, we conducted field research to record the indigenous method of cloth dyeing using madder dye. An aqueous extract of the root of Rubia wallichiana is a traditional madder dye. In this study, we used traditional dye and ethyl alcohol extract of the residue of aqueous extract. Two fabrics were dyed with the extractions in the presence of one of the metallic mordants or biomordants. Pigment compounds from aqueous extraction of madder and ethyl alcohol extraction of recycled madder were evaluated using Phytochem...

Research paper thumbnail of Mapping tree species distribution in support of China's integrated tree-livestock-crop system

Circular Agricultural Systems, 2021

The primary challenge of the contemporary world is to meet accelerating requirements for food. Li... more The primary challenge of the contemporary world is to meet accelerating requirements for food. Limited land, competition between crop and livestock farming and climate change are major challenges. Agroforestry offer a form of sustainable agriculture through the direct provision of food by raising farmers' incomes and through various ecosystem services. The first essential step in adopting agroforestry is the selection of appropriate tree species that fit local climates. In this paper, we mapped 20 fodder trees and important crops in China using the multi-model ensemble and Ecocrop modelling approach. Relying on the intersectional concept of set theory, the fuzzy logic technique was applied to identify regions where candidate trees could be grown with appropriate crops and livestock. The resulting models provide important insights into the climatic suitability of trees and crops and offer knowledge critical to the proper integration of trees with crops and livestock at specific locations. The results offer support for developing appropriate strategies regarding potential land-use within agroforestry systems in order to maximize ecosystem services and the benefits of sustainable agriculture. Model outputs could easily convert into conventional maps with clearly defined boundaries for site-specific planning for tree-crop-livestock integration. The next step for actualizing an integrated system is to investigate specifically what these different species may contribute to the existing farming systems, quantify the benefits and estimate any possible tradeoffs.

Research paper thumbnail of Impacts of invasive alien plants on ecosystem services of Ramsar lake cluster in middle mountain Nepal

Global Ecology and Conservation, 2021

Biological invasions have significant impacts on ecosystems, the services provided by ecosystems,... more Biological invasions have significant impacts on ecosystems, the services provided by ecosystems, and associated economies. In wetlands, invasion by alien plants can impact the ecosystem services that are fundamental to human well-being. We conducted a stakeholder analysis in Ramsar sites in the Pokhara Valley to understand ecosystem services, the economic valuation of provisioning services, invasive alien plants, and their impacts. We collected information from locals living near the Ramsar site using focus group discussions, key informant interviews, and household (HH) surveys. We identified five invasive alien plants in the Ramsar sites in Pokhara Valley. A total of 18 ecosystem services were recorded from discussions with residents living near the Ramsar sites. Our study found that the economic benefits generated from the provisioning service, calculated based on the market price in the year of data collection, were worth a total of International$ 9.05 million. The value of provisioning services was International$ 0.1 million HH −1 year −1. Our estimate showed that the value of provisioning services before the occurrence of invasive alien plants in 1989 was International$ 0.19 million HH −1 year −1 higher than in 2019. Those who benefit from the Lake clusters mentioned that the invasive alien plants led to a decrease in economically important plants such as medicine and fruits and decreased fish production. Other impacts have included: reduced natural beauty, loss of biodiversity, and obstruction of recreational boating, which has discouraged tourism in recent years, among other impacts. Our results show that the rampant spread of invasive alien plants has a severe impact on ecosystem services. The impact on the associated economic value is alarming. There is an urgent need for proper management of wetlands. The findings from our results can help make decision-makers aware of the need to act in order to restore and maintain the services provided by the wetlands.

Research paper thumbnail of Will heat stress take its toll on milk production in China?

Climatic Change, 2020

There are clear signs that milk production growth is leveling off, and recently even declining, i... more There are clear signs that milk production growth is leveling off, and recently even declining, in China. Heat stress is one of the main reasons for the recent reduction in milk production. In this study, we computed the change in milk production as a result of heat stress in major milk production areas in China. We constructed a temperature–humidity index (THI) spatial layer to understand the monthly distribution of heat and moisture. We documented specific areas in northern China where cattle were at high risk to heat stress in specific months. THI values exceeded the threshold above which milk production declines during months of June, July, and August. Especially during July, the THI value was higher than the production threshold in recent years (2008 to 2016) and in projected future scenarios (2050 and 2070). THI-based milk yield losses were up from 0.7 to about 4 kg per cow per day in July 2016. These losses are projected to increase from 1.5 to 6.5 kg in 2050 and 2 to 7.2 kg in 2070 (representing production losses between 15 and 50%). These results suggest that climate change will have significant consequences for the dairy sector in major milk-producing areas in China. Our results are useful in identifying areas susceptible to heat stress where adaptive livestock management practices are needed to prevent significant production decreases.

Research paper thumbnail of Determining bioclimatic space of Himalayan alder for agroforestry systems in Nepal

Plant diversity, 2018

Himalayan alder species are proven to be very useful in traditional as well as contemporary agrof... more Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of spp. were modelled in MaxEnt software using a subset of least correlated bioclimatic variables for current conditions (1950-2000), topographic variables (DEM derived) and Landuse Landcover (LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models (ESM) were used. Our model revealed that the most favorable conditions for ar...

Research paper thumbnail of Selection of Native Tree Species for Subtropical Forest Restoration in Southwest China

PloS one, 2017

The use of native species in forest restoration has been increasingly recognized as an effective ... more The use of native species in forest restoration has been increasingly recognized as an effective means of restoring ecosystem functions and biodiversity to degraded areas across the world. However, successful selection of species adapted to local conditions requires specific knowledge which is often lacking, especially in developing countries. In order to scale up forest restoration, experimental data on the responses of native species to propagation and restoration treatments across a range of local conditions are required. In this study, the restoration potential of 34 native tree species was evaluated based on nursery research and field planting experiments at a highly degraded site in a subtropical area of southwest China. We examined species performance in terms of germination rates as well as survival rates and growth over 2 years after planting. Of the 34 species examined, 25 had a germination percentage greater than 50%. Survivorship ranged from 0 to 97% across species and w...

Research paper thumbnail of Predicting the impact of climate change on the distribution of two threatened Himalayan medicinal plants of Liliaceae in Nepal

Journal of Mountain Science, 2017

Species distribution modeling is an important tool that uses ecological data to aid in biological... more Species distribution modeling is an important tool that uses ecological data to aid in biological conservation. In the present study we used prediction methods, including maximum entropy (Maxent), to project the distribution of the Persian Spider gecko and the impact of climate change on its distribution in Iran. The results were consistent between models and indicated that two of the most important variables in determining distribution of Agamura persica are mean temperature of the wettest quarter and temperature seasonality. All of the models used in this study obtained high area-under-thecurve (AUC) values. Because of the nocturnal behavior of the species, these variables can directly affect species' activity by determining the vegetation type in habitat. Suitable habitats of Agamura persica were in two locations in eastern Iran and a third location in the central plateau. Habitat suitability for this species was increased in the last glacial maximum (LGM), at which time most parts of the Iranian Plateau were suitable (even southwest Iran). However, the suitable habitat area is restricted to the central part of the plateau in the current period. Predictions from four scenarios indicate that future habitat suitability will be patchy and that the central part of the plateau will remain the most important part of the species distribution.

Research paper thumbnail of Insights into the Genetic Relationships and Breeding Patterns of the African Tea Germplasm Based on nSSR Markers and cpDNA Sequences

Frontiers in plant science, 2016

Africa is one of the key centers of global tea production. Understanding the genetic diversity an... more Africa is one of the key centers of global tea production. Understanding the genetic diversity and relationships of cultivars of African tea is important for future targeted breeding efforts for new crop cultivars, specialty tea processing, and to guide germplasm conservation efforts. Despite the economic importance of tea in Africa, no research work has been done so far on its genetic diversity at a continental scale. Twenty-three nSSRs and three plastid DNA regions were used to investigate the genetic diversity, relationships, and breeding patterns of tea accessions collected from eight countries of Africa. A total of 280 African tea accessions generated 297 alleles with a mean of 12.91 alleles per locus and a genetic diversity (H S) estimate of 0.652. A STRUCTURE analysis suggested two main genetic groups of African tea accessions which corresponded well with the two tea types Camellia sinensis var. sinensis and C. sinensis var. assamica, respectively, as well as an admixed &quot...

Research paper thumbnail of Effect of elevation and latitude on spring phenology of Rhododendron at Kanchenjunga Conservation Area, East Nepal

International Journal of Applied Sciences and Biotechnology, 2013

Mountainous terrain in East corner of Nepal is good location for phenological studies. Spring phe... more Mountainous terrain in East corner of Nepal is good location for phenological studies. Spring phenology in Rhododendron arboreum Sm. was monitored around Ghunsa river valley in Kanchenjunga Conservation Area of Nepal. Observations were carried our following the crown density method; flowering events of the selected species were recorded in 15-days interval. Flowering activity including duration of flowering and synchrony were determined. In addition, expected difference in flower onset time in two consecutive monitoring plots was determined. Elevation, latitude and longitude were regressed against flower onset to determine effect of each variable on flower onset. Delay in flower onset with rise in elevation, North latitude and West longitude was found in the results of the regression. Full bloom phase was found highly synchronized throughout the elevation gradient with contraction of flowering duration. High synchrony also indicates that the reproductive timing might plastic enough ...

Research paper thumbnail of Chilling and heat requirements for flowering in temperate fruit trees

International Journal of Biometeorology, 2013

Climate change has affected the rates of chilling and heat accumulation, which are vital for flow... more Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut (Castanea mollissima Blume) and jujube (Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing's cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

Research paper thumbnail of Ensemble forecast of climate suitability for the Trans-Himalayan Nyctaginaceae species

Ecological Modelling, 2014

Research paper thumbnail of Yield and household consumption of Rhododendron arboreum as a fuelwood species in Eastern Nepal

Biomass and Bioenergy, 2014

ABSTRACT Rhododendron arboreum Sm. is commonly used for fuelwood in mountainous regions of the Ea... more ABSTRACT Rhododendron arboreum Sm. is commonly used for fuelwood in mountainous regions of the Eastern Himalaya, however nothing is known about rates of extraction versus the annual increment capacity of the species in terms of biomass. In the study area, fuelwood is the major source of energy. We conducted household surveys and ecological surveys in and near two settlements to assess both fuelwood consumption and existing above ground biomass of R. arboreum. According to local residents, this species contributes 20–25% to household fuelwood requirements, while forest surveys and a survey of freshly cut stumps indicate that 15% of trees felled for fuelwood were R. arboreum. Trees were mostly young, comprised about 20% of all tree species in the forest, and accounted for 70.41 × 10^3 kg ha^−1 biomass in average. The biomass of felled trees was calculated as 8.71 × 10^3 kg ha^−1 at the time of study. Simulation based on the current rates of extraction and increment showed that the species will be in a critical condition in future at most of the monitored sites. In some places however, biomass was found to increase in spite of ongoing extraction. The results indicate that there is an urgent need of forest management which in a first step can be achieved through rotational harvesting that allows forest stands to regenerate and build up biomass. In addition, depletion of rhododendron stands can be reduced by economic development through ecotourism on the theme of rhododendrons, and by providing access to alternative sources of energy.

Research paper thumbnail of Suitability Analysis and Projected Climate Change Impact on Banana and Coffee Production Zones in Nepal

PloS one

The Government of Nepal has identified opportunities in agricultural commercialization, respondin... more The Government of Nepal has identified opportunities in agricultural commercialization, responding to a growing internal demand and expansion of export markets to reduce the immense trade deficit. Several cash crops, including coffee and bananas, have been identified in the recently approved Agriculture Development Strategy. Both of these crops have encouraged smallholder farmers to convert their subsistence farming practices to more commercial cultivation. Identification of suitable agro-ecological zones and understanding climate-related issues are important for improved production and livelihoods of smallholder farmers. Here, the suitability of coffee and banana crops is analyzed for different agro-ecological zones represented by Global Environmental Stratification (GEnS). Future shifts in these suitability zones are also predicted. Plantation sites in Nepal were geo-referenced and used as input in species distribution modelling. The multi-model ensemble model suggests that climat...

Research paper thumbnail of Climate-Fungal Pathogen Modeling Predicts Loss of Up to One-Third of Tea Growing Areas

Frontiers in Cellular and Infection Microbiology, 2021

Climate change will affect numerous crops in the future; however, perennial crops, such as tea, a... more Climate change will affect numerous crops in the future; however, perennial crops, such as tea, are particularly vulnerable. Climate change will also strongly influence fungal pathogens. Here, we predict how future climatic conditions will impact tea and its associated pathogens. We collected data on the three most important fungal pathogens of tea (Colletotrichum acutatum, Co. camelliae, and Exobasidium vexans) and then modeled distributions of tea and these fungal pathogens using current and projected climates. The models show that baseline tea-growing areas will become unsuitable for Camellia sinensis var. sinensis (15 to 32% loss) and C. sinensis var. assamica (32 to 34% loss) by 2050. Although new areas will become more suitable for tea cultivation, existing and potentially new fungal pathogens will present challenges in these areas, and they are already under other land-use regimes. In addition, future climatic scenarios suitable range of fungal species and tea suitable cultiv...

Research paper thumbnail of Traditional Knowledge of Plant Dyeing, Sustainable Practices and Potential for Improved Techniques by Monpa in Tibet, China

BackgroundNatural dyes used since historic times for coloring food, leather, textile fibers, and ... more BackgroundNatural dyes used since historic times for coloring food, leather, textile fibers, and paint body parts. The use of natural dyes has suffered drastically under the influence of modern technologies in the textile industry and socio-economic changes. Hence, ethnobotanical studies of indigenous dye plants and dyeing craft in local communities are urged to protect their potential ecological and economic value. MethodsWe conducted semi-structured surveys on dye plants and traditional craft in 11 Monpa villages of Mêdog County, South-east Tibet, China. The cultural significance of local dye plants was evaluated by an index of cultural importance (CI). Field research was conducted to record the indigenous madder (the root of Rubia wallichiana Decne.) dyeing craft. An experiment was performed with aqueous extract and ethyl alcohol extract of residue remained after water extraction. These two dye solutions were respectively used to dye two fabrics with two biomordants and two metal...

Research paper thumbnail of Assessing the Livelihood Vulnerability of Rural Indigenous Households to Climate Changes in Central Nepal, Himalaya

Sustainability

Climate change and related hazards affect the livelihoods of people and their vulnerability to sh... more Climate change and related hazards affect the livelihoods of people and their vulnerability to shocks and stresses. Though research on the linkages between a changing climate and vulnerability has been increasing, only a few studies have examined the caste/ethnicity and gender dimensions of livelihood vulnerability. In this study, we attempt to explore how cultural and gender-related aspects influence livelihood vulnerability in indigenous farming mountain communities of the Nepal Himalaya in the context of climate change. We applied the Livelihood Vulnerability Index (LVI) to estimate household (social group and gender-based) vulnerability in farming communities in the Melamchi River Valley, Nepal. The results identified female-headed families, and those belonging to disadvantaged social groups as more vulnerable and in need of being preferentially targeted by policy measures. Higher exposure to climatic extremes and related hazards, dependency on natural resources, lack of financi...

Research paper thumbnail of Effectiveness of protected areas in preventing rubber expansion and deforestation in Xishuangbanna, Southwest China

Land Degradation & Development

Protected areas (PAs) are supposedly key refuges for the world's remaining biodiversity. Our ... more Protected areas (PAs) are supposedly key refuges for the world's remaining biodiversity. Our study site, Xishuangbanna, harbors a high proportion of China's biodiversity but is threatened by rapid deforestation and expansion of monoculture rubber. We quantified the success of Xishuangbanna's PAs in preventing deforestation. Most previous analyses of PA effectiveness have insufficiently accounted for biases arising from PA location and establishment, because they overlooked the importance of site-matching in accounting for landscape change. We used matching methods to minimize such biases in comparing land use conversion rates inside and outside-PAs. By 2010, Xishuangbanna had 3,455.5km(2) (similar to 18%) designated as PAs. However, rubber occupied 22% of its land area and was expanding at a rate of 153.4km(2)/year. Between 1988 and 2010, conventional analysis showed a deforestation rate of 9.3km(2)/year. However, matching analysis showed a significantly higher rate of deforestation, 10.7km(2)/year, which resulted in the deforestation of similar to 11% of PA's land. We argue that PAs were less effective than had previously been thought. The situation worsened from 2002 to 2010, when the deforestation rate within PAs was actually higher than that of outside PAs, although this difference was not significant. The designated higher levels of protection in core' zones were also unsuccessful in preventing deforestation. At current rates, within the next 50years, a further 16% of PAs would be deforested in Xishuangbanna. This could even be an underestimate, as without intervention, drivers of deforestation tend to accelerate. Therefore, reviewing and strengthening current PA management policies is essential.

Research paper thumbnail of Species distribution and ecological niche modelling of Alnus species in Nepal A Master Degree Dissertation, CDB, TU

Research paper thumbnail of Lu et al 2016.pdf

Research paper thumbnail of Research Article EFFECT OF ELEVATION AND LATITUDE ON SPRING PHENOLOGY OF

Mountainous terrain in the East corner of Nepal is a good location for phenological studies. Spri... more Mountainous terrain in the East corner of Nepal is a good location for phenological studies. Spring phenology in Rhododendron arboreum Sm. was monitored around the Ghunsa river valley in Kanchenjunga Conservation Area of Nepal. Observations were carried out following the crown density method; flowering events of the selected species were recorded in 15-days interval. Flowering activity including duration of flowering and synchrony were determined. In addition, expected difference in flower onset time in two consecutive monitoring plots was determined. Elevation, latitude and longitude were regressed against the flower onset to determine the effect of each variable on flower onset. Delay in flower onset along with rise in elevation, North latitude and West longitude was found in the results of the regression. Full bloom phase was found highly synchronized throughout the elevation gradient with contraction of flowering duration. High synchrony also indicates that the reproductive timi...

Research paper thumbnail of Reusing wasteroot of Rubia wallichiana dyeing from Monpa of Tibet in China

Scientific Reports, 2021

Humans have dyed textiles and leather, colored food, and paint body parts using natural dyes thro... more Humans have dyed textiles and leather, colored food, and paint body parts using natural dyes throughout history. Natural dyes have suffered drastically due to recent socioeconomic changes and replacement with synthetic dye in the textile industry. Hence, it is urgent to study indigenous dye plants and dyeing craft in local communities to protect these resources' potential ecological, economic, and cultural values. In 11 Monpa villages of Mêdog County, South-east Tibet, China, we conducted field research to record the indigenous method of cloth dyeing using madder dye. An aqueous extract of the root of Rubia wallichiana is a traditional madder dye. In this study, we used traditional dye and ethyl alcohol extract of the residue of aqueous extract. Two fabrics were dyed with the extractions in the presence of one of the metallic mordants or biomordants. Pigment compounds from aqueous extraction of madder and ethyl alcohol extraction of recycled madder were evaluated using Phytochem...

Research paper thumbnail of Mapping tree species distribution in support of China's integrated tree-livestock-crop system

Circular Agricultural Systems, 2021

The primary challenge of the contemporary world is to meet accelerating requirements for food. Li... more The primary challenge of the contemporary world is to meet accelerating requirements for food. Limited land, competition between crop and livestock farming and climate change are major challenges. Agroforestry offer a form of sustainable agriculture through the direct provision of food by raising farmers' incomes and through various ecosystem services. The first essential step in adopting agroforestry is the selection of appropriate tree species that fit local climates. In this paper, we mapped 20 fodder trees and important crops in China using the multi-model ensemble and Ecocrop modelling approach. Relying on the intersectional concept of set theory, the fuzzy logic technique was applied to identify regions where candidate trees could be grown with appropriate crops and livestock. The resulting models provide important insights into the climatic suitability of trees and crops and offer knowledge critical to the proper integration of trees with crops and livestock at specific locations. The results offer support for developing appropriate strategies regarding potential land-use within agroforestry systems in order to maximize ecosystem services and the benefits of sustainable agriculture. Model outputs could easily convert into conventional maps with clearly defined boundaries for site-specific planning for tree-crop-livestock integration. The next step for actualizing an integrated system is to investigate specifically what these different species may contribute to the existing farming systems, quantify the benefits and estimate any possible tradeoffs.

Research paper thumbnail of Impacts of invasive alien plants on ecosystem services of Ramsar lake cluster in middle mountain Nepal

Global Ecology and Conservation, 2021

Biological invasions have significant impacts on ecosystems, the services provided by ecosystems,... more Biological invasions have significant impacts on ecosystems, the services provided by ecosystems, and associated economies. In wetlands, invasion by alien plants can impact the ecosystem services that are fundamental to human well-being. We conducted a stakeholder analysis in Ramsar sites in the Pokhara Valley to understand ecosystem services, the economic valuation of provisioning services, invasive alien plants, and their impacts. We collected information from locals living near the Ramsar site using focus group discussions, key informant interviews, and household (HH) surveys. We identified five invasive alien plants in the Ramsar sites in Pokhara Valley. A total of 18 ecosystem services were recorded from discussions with residents living near the Ramsar sites. Our study found that the economic benefits generated from the provisioning service, calculated based on the market price in the year of data collection, were worth a total of International$ 9.05 million. The value of provisioning services was International$ 0.1 million HH −1 year −1. Our estimate showed that the value of provisioning services before the occurrence of invasive alien plants in 1989 was International$ 0.19 million HH −1 year −1 higher than in 2019. Those who benefit from the Lake clusters mentioned that the invasive alien plants led to a decrease in economically important plants such as medicine and fruits and decreased fish production. Other impacts have included: reduced natural beauty, loss of biodiversity, and obstruction of recreational boating, which has discouraged tourism in recent years, among other impacts. Our results show that the rampant spread of invasive alien plants has a severe impact on ecosystem services. The impact on the associated economic value is alarming. There is an urgent need for proper management of wetlands. The findings from our results can help make decision-makers aware of the need to act in order to restore and maintain the services provided by the wetlands.

Research paper thumbnail of Will heat stress take its toll on milk production in China?

Climatic Change, 2020

There are clear signs that milk production growth is leveling off, and recently even declining, i... more There are clear signs that milk production growth is leveling off, and recently even declining, in China. Heat stress is one of the main reasons for the recent reduction in milk production. In this study, we computed the change in milk production as a result of heat stress in major milk production areas in China. We constructed a temperature–humidity index (THI) spatial layer to understand the monthly distribution of heat and moisture. We documented specific areas in northern China where cattle were at high risk to heat stress in specific months. THI values exceeded the threshold above which milk production declines during months of June, July, and August. Especially during July, the THI value was higher than the production threshold in recent years (2008 to 2016) and in projected future scenarios (2050 and 2070). THI-based milk yield losses were up from 0.7 to about 4 kg per cow per day in July 2016. These losses are projected to increase from 1.5 to 6.5 kg in 2050 and 2 to 7.2 kg in 2070 (representing production losses between 15 and 50%). These results suggest that climate change will have significant consequences for the dairy sector in major milk-producing areas in China. Our results are useful in identifying areas susceptible to heat stress where adaptive livestock management practices are needed to prevent significant production decreases.

Research paper thumbnail of Determining bioclimatic space of Himalayan alder for agroforestry systems in Nepal

Plant diversity, 2018

Himalayan alder species are proven to be very useful in traditional as well as contemporary agrof... more Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of spp. were modelled in MaxEnt software using a subset of least correlated bioclimatic variables for current conditions (1950-2000), topographic variables (DEM derived) and Landuse Landcover (LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models (ESM) were used. Our model revealed that the most favorable conditions for ar...

Research paper thumbnail of Selection of Native Tree Species for Subtropical Forest Restoration in Southwest China

PloS one, 2017

The use of native species in forest restoration has been increasingly recognized as an effective ... more The use of native species in forest restoration has been increasingly recognized as an effective means of restoring ecosystem functions and biodiversity to degraded areas across the world. However, successful selection of species adapted to local conditions requires specific knowledge which is often lacking, especially in developing countries. In order to scale up forest restoration, experimental data on the responses of native species to propagation and restoration treatments across a range of local conditions are required. In this study, the restoration potential of 34 native tree species was evaluated based on nursery research and field planting experiments at a highly degraded site in a subtropical area of southwest China. We examined species performance in terms of germination rates as well as survival rates and growth over 2 years after planting. Of the 34 species examined, 25 had a germination percentage greater than 50%. Survivorship ranged from 0 to 97% across species and w...

Research paper thumbnail of Predicting the impact of climate change on the distribution of two threatened Himalayan medicinal plants of Liliaceae in Nepal

Journal of Mountain Science, 2017

Species distribution modeling is an important tool that uses ecological data to aid in biological... more Species distribution modeling is an important tool that uses ecological data to aid in biological conservation. In the present study we used prediction methods, including maximum entropy (Maxent), to project the distribution of the Persian Spider gecko and the impact of climate change on its distribution in Iran. The results were consistent between models and indicated that two of the most important variables in determining distribution of Agamura persica are mean temperature of the wettest quarter and temperature seasonality. All of the models used in this study obtained high area-under-thecurve (AUC) values. Because of the nocturnal behavior of the species, these variables can directly affect species' activity by determining the vegetation type in habitat. Suitable habitats of Agamura persica were in two locations in eastern Iran and a third location in the central plateau. Habitat suitability for this species was increased in the last glacial maximum (LGM), at which time most parts of the Iranian Plateau were suitable (even southwest Iran). However, the suitable habitat area is restricted to the central part of the plateau in the current period. Predictions from four scenarios indicate that future habitat suitability will be patchy and that the central part of the plateau will remain the most important part of the species distribution.

Research paper thumbnail of Insights into the Genetic Relationships and Breeding Patterns of the African Tea Germplasm Based on nSSR Markers and cpDNA Sequences

Frontiers in plant science, 2016

Africa is one of the key centers of global tea production. Understanding the genetic diversity an... more Africa is one of the key centers of global tea production. Understanding the genetic diversity and relationships of cultivars of African tea is important for future targeted breeding efforts for new crop cultivars, specialty tea processing, and to guide germplasm conservation efforts. Despite the economic importance of tea in Africa, no research work has been done so far on its genetic diversity at a continental scale. Twenty-three nSSRs and three plastid DNA regions were used to investigate the genetic diversity, relationships, and breeding patterns of tea accessions collected from eight countries of Africa. A total of 280 African tea accessions generated 297 alleles with a mean of 12.91 alleles per locus and a genetic diversity (H S) estimate of 0.652. A STRUCTURE analysis suggested two main genetic groups of African tea accessions which corresponded well with the two tea types Camellia sinensis var. sinensis and C. sinensis var. assamica, respectively, as well as an admixed &quot...

Research paper thumbnail of Effect of elevation and latitude on spring phenology of Rhododendron at Kanchenjunga Conservation Area, East Nepal

International Journal of Applied Sciences and Biotechnology, 2013

Mountainous terrain in East corner of Nepal is good location for phenological studies. Spring phe... more Mountainous terrain in East corner of Nepal is good location for phenological studies. Spring phenology in Rhododendron arboreum Sm. was monitored around Ghunsa river valley in Kanchenjunga Conservation Area of Nepal. Observations were carried our following the crown density method; flowering events of the selected species were recorded in 15-days interval. Flowering activity including duration of flowering and synchrony were determined. In addition, expected difference in flower onset time in two consecutive monitoring plots was determined. Elevation, latitude and longitude were regressed against flower onset to determine effect of each variable on flower onset. Delay in flower onset with rise in elevation, North latitude and West longitude was found in the results of the regression. Full bloom phase was found highly synchronized throughout the elevation gradient with contraction of flowering duration. High synchrony also indicates that the reproductive timing might plastic enough ...

Research paper thumbnail of Chilling and heat requirements for flowering in temperate fruit trees

International Journal of Biometeorology, 2013

Climate change has affected the rates of chilling and heat accumulation, which are vital for flow... more Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut (Castanea mollissima Blume) and jujube (Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing's cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

Research paper thumbnail of Ensemble forecast of climate suitability for the Trans-Himalayan Nyctaginaceae species

Ecological Modelling, 2014

Research paper thumbnail of Yield and household consumption of Rhododendron arboreum as a fuelwood species in Eastern Nepal

Biomass and Bioenergy, 2014

ABSTRACT Rhododendron arboreum Sm. is commonly used for fuelwood in mountainous regions of the Ea... more ABSTRACT Rhododendron arboreum Sm. is commonly used for fuelwood in mountainous regions of the Eastern Himalaya, however nothing is known about rates of extraction versus the annual increment capacity of the species in terms of biomass. In the study area, fuelwood is the major source of energy. We conducted household surveys and ecological surveys in and near two settlements to assess both fuelwood consumption and existing above ground biomass of R. arboreum. According to local residents, this species contributes 20–25% to household fuelwood requirements, while forest surveys and a survey of freshly cut stumps indicate that 15% of trees felled for fuelwood were R. arboreum. Trees were mostly young, comprised about 20% of all tree species in the forest, and accounted for 70.41 × 10^3 kg ha^−1 biomass in average. The biomass of felled trees was calculated as 8.71 × 10^3 kg ha^−1 at the time of study. Simulation based on the current rates of extraction and increment showed that the species will be in a critical condition in future at most of the monitored sites. In some places however, biomass was found to increase in spite of ongoing extraction. The results indicate that there is an urgent need of forest management which in a first step can be achieved through rotational harvesting that allows forest stands to regenerate and build up biomass. In addition, depletion of rhododendron stands can be reduced by economic development through ecotourism on the theme of rhododendrons, and by providing access to alternative sources of energy.

Research paper thumbnail of Suitability Analysis and Projected Climate Change Impact on Banana and Coffee Production Zones in Nepal

PloS one

The Government of Nepal has identified opportunities in agricultural commercialization, respondin... more The Government of Nepal has identified opportunities in agricultural commercialization, responding to a growing internal demand and expansion of export markets to reduce the immense trade deficit. Several cash crops, including coffee and bananas, have been identified in the recently approved Agriculture Development Strategy. Both of these crops have encouraged smallholder farmers to convert their subsistence farming practices to more commercial cultivation. Identification of suitable agro-ecological zones and understanding climate-related issues are important for improved production and livelihoods of smallholder farmers. Here, the suitability of coffee and banana crops is analyzed for different agro-ecological zones represented by Global Environmental Stratification (GEnS). Future shifts in these suitability zones are also predicted. Plantation sites in Nepal were geo-referenced and used as input in species distribution modelling. The multi-model ensemble model suggests that climat...

Research paper thumbnail of Climate-Fungal Pathogen Modeling Predicts Loss of Up to One-Third of Tea Growing Areas

Frontiers in Cellular and Infection Microbiology, 2021

Climate change will affect numerous crops in the future; however, perennial crops, such as tea, a... more Climate change will affect numerous crops in the future; however, perennial crops, such as tea, are particularly vulnerable. Climate change will also strongly influence fungal pathogens. Here, we predict how future climatic conditions will impact tea and its associated pathogens. We collected data on the three most important fungal pathogens of tea (Colletotrichum acutatum, Co. camelliae, and Exobasidium vexans) and then modeled distributions of tea and these fungal pathogens using current and projected climates. The models show that baseline tea-growing areas will become unsuitable for Camellia sinensis var. sinensis (15 to 32% loss) and C. sinensis var. assamica (32 to 34% loss) by 2050. Although new areas will become more suitable for tea cultivation, existing and potentially new fungal pathogens will present challenges in these areas, and they are already under other land-use regimes. In addition, future climatic scenarios suitable range of fungal species and tea suitable cultiv...

Research paper thumbnail of Traditional Knowledge of Plant Dyeing, Sustainable Practices and Potential for Improved Techniques by Monpa in Tibet, China

BackgroundNatural dyes used since historic times for coloring food, leather, textile fibers, and ... more BackgroundNatural dyes used since historic times for coloring food, leather, textile fibers, and paint body parts. The use of natural dyes has suffered drastically under the influence of modern technologies in the textile industry and socio-economic changes. Hence, ethnobotanical studies of indigenous dye plants and dyeing craft in local communities are urged to protect their potential ecological and economic value. MethodsWe conducted semi-structured surveys on dye plants and traditional craft in 11 Monpa villages of Mêdog County, South-east Tibet, China. The cultural significance of local dye plants was evaluated by an index of cultural importance (CI). Field research was conducted to record the indigenous madder (the root of Rubia wallichiana Decne.) dyeing craft. An experiment was performed with aqueous extract and ethyl alcohol extract of residue remained after water extraction. These two dye solutions were respectively used to dye two fabrics with two biomordants and two metal...

Research paper thumbnail of Assessing the Livelihood Vulnerability of Rural Indigenous Households to Climate Changes in Central Nepal, Himalaya

Sustainability

Climate change and related hazards affect the livelihoods of people and their vulnerability to sh... more Climate change and related hazards affect the livelihoods of people and their vulnerability to shocks and stresses. Though research on the linkages between a changing climate and vulnerability has been increasing, only a few studies have examined the caste/ethnicity and gender dimensions of livelihood vulnerability. In this study, we attempt to explore how cultural and gender-related aspects influence livelihood vulnerability in indigenous farming mountain communities of the Nepal Himalaya in the context of climate change. We applied the Livelihood Vulnerability Index (LVI) to estimate household (social group and gender-based) vulnerability in farming communities in the Melamchi River Valley, Nepal. The results identified female-headed families, and those belonging to disadvantaged social groups as more vulnerable and in need of being preferentially targeted by policy measures. Higher exposure to climatic extremes and related hazards, dependency on natural resources, lack of financi...

Research paper thumbnail of Effectiveness of protected areas in preventing rubber expansion and deforestation in Xishuangbanna, Southwest China

Land Degradation & Development

Protected areas (PAs) are supposedly key refuges for the world's remaining biodiversity. Our ... more Protected areas (PAs) are supposedly key refuges for the world's remaining biodiversity. Our study site, Xishuangbanna, harbors a high proportion of China's biodiversity but is threatened by rapid deforestation and expansion of monoculture rubber. We quantified the success of Xishuangbanna's PAs in preventing deforestation. Most previous analyses of PA effectiveness have insufficiently accounted for biases arising from PA location and establishment, because they overlooked the importance of site-matching in accounting for landscape change. We used matching methods to minimize such biases in comparing land use conversion rates inside and outside-PAs. By 2010, Xishuangbanna had 3,455.5km(2) (similar to 18%) designated as PAs. However, rubber occupied 22% of its land area and was expanding at a rate of 153.4km(2)/year. Between 1988 and 2010, conventional analysis showed a deforestation rate of 9.3km(2)/year. However, matching analysis showed a significantly higher rate of deforestation, 10.7km(2)/year, which resulted in the deforestation of similar to 11% of PA's land. We argue that PAs were less effective than had previously been thought. The situation worsened from 2002 to 2010, when the deforestation rate within PAs was actually higher than that of outside PAs, although this difference was not significant. The designated higher levels of protection in core' zones were also unsuccessful in preventing deforestation. At current rates, within the next 50years, a further 16% of PAs would be deforested in Xishuangbanna. This could even be an underestimate, as without intervention, drivers of deforestation tend to accelerate. Therefore, reviewing and strengthening current PA management policies is essential.