Upland cotton encounters biotic and abiotic stresses during the growing season, which significant... more Upland cotton encounters biotic and abiotic stresses during the growing season, which significantly affects the genetic potential of stress tolerance and productivity. The root-knot nematode (RKN) (Meloidogyne incognita) is a soilborne roundworm affecting cotton production. The occurrence of abiotic stress (drought stress, DS) can alter the plant–disease (RKN) interactions by enhancing host plant sensitivity. Experiments were conducted for two years under greenhouse conditions to investigate the effect of RKN and DS and their combination using nematode-resistant (Rk-Rn-1) and nematode susceptible (M8) cotton genotypes. These genotypes were subjected to four treatments: control (100% irrigation with no nematodes), RKN (100% irrigation with nematodes), DS (50% irrigation with no nematodes), and DS + RKN (50% irrigation with nematodes). We measured treatments-induced changes in cotton (i) leaf reflectance between 350 and 2500 nm; and (ii) physiology and biomass-related traits for diagn...
Automated long-term mapping and climate niche modeling are important for developing adaptation an... more Automated long-term mapping and climate niche modeling are important for developing adaptation and management strategies for rubber plantations (RP). Landsat imageries at the defoliation and refoliation stages were employed for RP mapping in the Indian state of Tripura. A decision tree classifier was applied to Landsat image-derived vegetation indices (Normalized Difference Vegetation Index and Difference Vegetation Index) for mapping RPs at two-three years intervals from 1990 to 2017. A comparison with actual plantation data indicated more than 91% mapping accuracy, with most RPs able to be identified within six years of plantation, while several patches were detected after six years of plantations. The RP patches identified in 1990 and before 2000 were used for training the Maxent species distribution model, wherein bioclimatic variables for 1960–1990 and 1970–2000 were used as predictor variables, respectively. The model-estimated suitability maps were validated using the success...
Several factors describe the broad pattern of diversity in plant species distribution. We explore... more Several factors describe the broad pattern of diversity in plant species distribution. We explore these determinants of species richness in Western Himalayas using high-resolution species data available for the area to energy, water, physiography and anthropogenic disturbance. The floral data involves 1279 species from 1178 spatial locations and 738 sample plots of a national database. We evaluated their correlation with 8-environmental variables, selected on the basis of correlation coefficients and principal component loadings, using both linear (structural equation model) and nonlinear (generalised additive model) techniques. There were 645 genera and 176 families including 815 herbs, 213 shrubs, 190 trees, and 61 lianas. The nonlinear model explained the maximum deviance of 67.4% and showed the dominant contribution of climate on species richness with a 59% share. Energy variables (potential evapotranspiration and temperature seasonality) explained the deviance better than did w...
Climate change poses significant challenges to distribution of plant species. Rhododendron arbore... more Climate change poses significant challenges to distribution of plant species. Rhododendron arboreum is considered as a keystone species between subalpine and the alpine regions. In the present study, we predict its future distribution in the Indian part of Western Himalaya by employing two species distribution modelling techniques. We used five least correlated climate variables: mean diurnal temperature range, annual mean temperature, annual precipitation, precipitation of driest quarter and precipitation seasonality to predict the potential distribution of R. arboreum for the current condition. We subtracted the current distribution from projected maps of the Representative Concentration Pathways (RCP) 4.5 and RCP 6.0 scenarios for the year 2070 to quantify the magnitude and direction of range shift of the species in the future environment. Rhododendron arboreum is predicted to shift its distribution towards higher elevations more prominently in case of RCP 6.0. The species is lik...
Understanding the patterns of biodiversity is central to species conservation planning. Here we i... more Understanding the patterns of biodiversity is central to species conservation planning. Here we illustrate chiropteran diversity and distribution pattern of the hill ranges of the Eastern Ghats of Odisha state, India using roost survey and mist net survey techniques. The present study recorded 23 bat species including two newly recorded species for the study site i.e., Hipposideros galeritus and Megaderma spasma. The bat capture rate was the highest in the moist deciduous forest describing higher bat populations compared with the places of human habitation. Utilities of 21 climate, three physiographic and two disturbance variables and species distribution modeling could reveal that the north-eastern part was more suitable for bat distributions than the southern part of the region. The climate, physiographic and disturbance variables were crucial in their distributions, where elevation and potential evapotranspiration were highly significant. Unlike other species, Taphozous melanopogon showed negative correlation with these variables. The mean diurnal temperature and precipitation seasonality have positive influence on bat distributions, indicating their resilience to seasonal precipitation changes and day time temperature fluctuations. The negative effect of temperature seasonality on the distribution of Pteropus giganteus could attribute to its vulnerability to climate change effects. The study provides inputs for monitoring the future spatio-temporal changes, suggesting long term conservation measures. It could generate basic information on the impacts of climate change on bat distribution in the future climate change scenario.
In spite of many theoretical explanations, the plant richness pattern along the mountain elevatio... more In spite of many theoretical explanations, the plant richness pattern along the mountain elevation gradient is still debatable. Here we considered East district of Sikkim state in the Eastern Himalaya to study plant richness pattern of vascular plants along an elevation gradient of 500–3300 m at 100, 200 and 300 m elevation steps. The study evaluates species area relationships along the elevation gradient, spread over four major forest types i.e., low (tropical to sub-tropical, up to 900 m), middle (subtropical, 750–1500 m), upper (wet temperate, 1500–2700 m) and Rhododendron-Conifer Zone (cold temperate/sub-alpine, 2700– 3600 m) with 664 species from 367 genera and 131 families. Pteridium aquilinum was found to be the most diverse species occurring in all 28-elevation steps along 500–3300 m, followed by Polystichum lentum, Polygonum runcinatum and Nephrolepis cordifolia those occured in 23 elevation steps. In general, a hump shaped pattern was observed for plant richness of all life forms along the elevation gradient. The peaks became prominent, with the increase in scale of extent from 100 m (R2=50%) to 300 m (R2=78%) through 200 m (R2=55%) elevation steps, using 2nd order polynomial ftting. The reduction in tree height and richness was noticed beyond 2300 m allowing dominance of herbs owing to climatic constraints. Using generalized additive model, temperature could explain the maximum deviance of>47%. Soil explained 36.4% deviance, followed by precipitation (21.6% deviance) in the plant richness. However, the ecotone efect of diferent forest types explained the mid-elevation peaks in plant richness more prominently than the geographic area availability. Further, inclusion of disturbance and biotic interactions may improve ecological understandings on the plant richness pattern along the elevation gradient.
Understanding the impact of climate change on species invasion is crucial for sustainable biodive... more Understanding the impact of climate change on species invasion is crucial for sustainable biodiversity conservation. Through this study, we try to answer how species differing in phenological cycles, specifically Cassia tora and Lantana camara, differ in the manner in which they invade new regions in India in the future climate. Since both species occupy identical niches, exploring their invasive potential in different climate change scenarios will offer critical insights into invasion and inform ecosystem management. We use three modelling protocols (i.e., maximum entropy, generalised linear model and generalised additive model) to predict the current distribution. Projections are made for both moderate (A1B) and extreme (A2) IPCC (Intergovernmental Panel on Climate Change) scenarios for the year 2050 and 2100. The study reveals that the distributions of C. tora (annual) and L. camara (perennial) would depend on the precipitation of the warmest quarter and moisture availability. C....
Understanding the patterns of biodiversity is central to species conservation planning. Here we i... more Understanding the patterns of biodiversity is central to species conservation planning. Here we illustrate chiropteran diversity and distribution pattern of the hill ranges of the Eastern Ghats of Odisha state, India using roost survey and mist net survey techniques. The present study recorded 23 bat species including two newly recorded species for the study site i.e., Hipposideros galeritus and Megaderma spasma. The bat capture rate was the highest in the moist deciduous forest describing higher bat populations compared with the places of human habitation. Utilities of 21 climate, three physiographic and two disturbance variables and species distribution modeling could reveal that the north-eastern part was more suitable for bat distributions than the southern part of the region. The climate, physiographic and disturbance variables were crucial in their distributions, where elevation and potential evapotranspiration were highly significant. Unlike other species, Taphozous melanopogon showed negative correlation with these variables. The mean diurnal temperature and precipitation seasonality have positive influence on bat distributions, indicating their resilience to seasonal precipitation changes and day time temperature fluctuations. The negative effect of temperature seasonality on the distribution of Pteropus giganteus could attribute to its vulnerability to climate change effects. The study provides inputs for monitoring the future spatio-temporal changes, suggesting long term conservation measures. It could generate basic information on the impacts of climate change on bat distribution in the future climate change scenario.
Upland cotton encounters biotic and abiotic stresses during the growing season, which significant... more Upland cotton encounters biotic and abiotic stresses during the growing season, which significantly affects the genetic potential of stress tolerance and productivity. The root-knot nematode (RKN) (Meloidogyne incognita) is a soilborne roundworm affecting cotton production. The occurrence of abiotic stress (drought stress, DS) can alter the plant–disease (RKN) interactions by enhancing host plant sensitivity. Experiments were conducted for two years under greenhouse conditions to investigate the effect of RKN and DS and their combination using nematode-resistant (Rk-Rn-1) and nematode susceptible (M8) cotton genotypes. These genotypes were subjected to four treatments: control (100% irrigation with no nematodes), RKN (100% irrigation with nematodes), DS (50% irrigation with no nematodes), and DS + RKN (50% irrigation with nematodes). We measured treatments-induced changes in cotton (i) leaf reflectance between 350 and 2500 nm; and (ii) physiology and biomass-related traits for diagn...
Automated long-term mapping and climate niche modeling are important for developing adaptation an... more Automated long-term mapping and climate niche modeling are important for developing adaptation and management strategies for rubber plantations (RP). Landsat imageries at the defoliation and refoliation stages were employed for RP mapping in the Indian state of Tripura. A decision tree classifier was applied to Landsat image-derived vegetation indices (Normalized Difference Vegetation Index and Difference Vegetation Index) for mapping RPs at two-three years intervals from 1990 to 2017. A comparison with actual plantation data indicated more than 91% mapping accuracy, with most RPs able to be identified within six years of plantation, while several patches were detected after six years of plantations. The RP patches identified in 1990 and before 2000 were used for training the Maxent species distribution model, wherein bioclimatic variables for 1960–1990 and 1970–2000 were used as predictor variables, respectively. The model-estimated suitability maps were validated using the success...
Several factors describe the broad pattern of diversity in plant species distribution. We explore... more Several factors describe the broad pattern of diversity in plant species distribution. We explore these determinants of species richness in Western Himalayas using high-resolution species data available for the area to energy, water, physiography and anthropogenic disturbance. The floral data involves 1279 species from 1178 spatial locations and 738 sample plots of a national database. We evaluated their correlation with 8-environmental variables, selected on the basis of correlation coefficients and principal component loadings, using both linear (structural equation model) and nonlinear (generalised additive model) techniques. There were 645 genera and 176 families including 815 herbs, 213 shrubs, 190 trees, and 61 lianas. The nonlinear model explained the maximum deviance of 67.4% and showed the dominant contribution of climate on species richness with a 59% share. Energy variables (potential evapotranspiration and temperature seasonality) explained the deviance better than did w...
Climate change poses significant challenges to distribution of plant species. Rhododendron arbore... more Climate change poses significant challenges to distribution of plant species. Rhododendron arboreum is considered as a keystone species between subalpine and the alpine regions. In the present study, we predict its future distribution in the Indian part of Western Himalaya by employing two species distribution modelling techniques. We used five least correlated climate variables: mean diurnal temperature range, annual mean temperature, annual precipitation, precipitation of driest quarter and precipitation seasonality to predict the potential distribution of R. arboreum for the current condition. We subtracted the current distribution from projected maps of the Representative Concentration Pathways (RCP) 4.5 and RCP 6.0 scenarios for the year 2070 to quantify the magnitude and direction of range shift of the species in the future environment. Rhododendron arboreum is predicted to shift its distribution towards higher elevations more prominently in case of RCP 6.0. The species is lik...
Understanding the patterns of biodiversity is central to species conservation planning. Here we i... more Understanding the patterns of biodiversity is central to species conservation planning. Here we illustrate chiropteran diversity and distribution pattern of the hill ranges of the Eastern Ghats of Odisha state, India using roost survey and mist net survey techniques. The present study recorded 23 bat species including two newly recorded species for the study site i.e., Hipposideros galeritus and Megaderma spasma. The bat capture rate was the highest in the moist deciduous forest describing higher bat populations compared with the places of human habitation. Utilities of 21 climate, three physiographic and two disturbance variables and species distribution modeling could reveal that the north-eastern part was more suitable for bat distributions than the southern part of the region. The climate, physiographic and disturbance variables were crucial in their distributions, where elevation and potential evapotranspiration were highly significant. Unlike other species, Taphozous melanopogon showed negative correlation with these variables. The mean diurnal temperature and precipitation seasonality have positive influence on bat distributions, indicating their resilience to seasonal precipitation changes and day time temperature fluctuations. The negative effect of temperature seasonality on the distribution of Pteropus giganteus could attribute to its vulnerability to climate change effects. The study provides inputs for monitoring the future spatio-temporal changes, suggesting long term conservation measures. It could generate basic information on the impacts of climate change on bat distribution in the future climate change scenario.
In spite of many theoretical explanations, the plant richness pattern along the mountain elevatio... more In spite of many theoretical explanations, the plant richness pattern along the mountain elevation gradient is still debatable. Here we considered East district of Sikkim state in the Eastern Himalaya to study plant richness pattern of vascular plants along an elevation gradient of 500–3300 m at 100, 200 and 300 m elevation steps. The study evaluates species area relationships along the elevation gradient, spread over four major forest types i.e., low (tropical to sub-tropical, up to 900 m), middle (subtropical, 750–1500 m), upper (wet temperate, 1500–2700 m) and Rhododendron-Conifer Zone (cold temperate/sub-alpine, 2700– 3600 m) with 664 species from 367 genera and 131 families. Pteridium aquilinum was found to be the most diverse species occurring in all 28-elevation steps along 500–3300 m, followed by Polystichum lentum, Polygonum runcinatum and Nephrolepis cordifolia those occured in 23 elevation steps. In general, a hump shaped pattern was observed for plant richness of all life forms along the elevation gradient. The peaks became prominent, with the increase in scale of extent from 100 m (R2=50%) to 300 m (R2=78%) through 200 m (R2=55%) elevation steps, using 2nd order polynomial ftting. The reduction in tree height and richness was noticed beyond 2300 m allowing dominance of herbs owing to climatic constraints. Using generalized additive model, temperature could explain the maximum deviance of>47%. Soil explained 36.4% deviance, followed by precipitation (21.6% deviance) in the plant richness. However, the ecotone efect of diferent forest types explained the mid-elevation peaks in plant richness more prominently than the geographic area availability. Further, inclusion of disturbance and biotic interactions may improve ecological understandings on the plant richness pattern along the elevation gradient.
Understanding the impact of climate change on species invasion is crucial for sustainable biodive... more Understanding the impact of climate change on species invasion is crucial for sustainable biodiversity conservation. Through this study, we try to answer how species differing in phenological cycles, specifically Cassia tora and Lantana camara, differ in the manner in which they invade new regions in India in the future climate. Since both species occupy identical niches, exploring their invasive potential in different climate change scenarios will offer critical insights into invasion and inform ecosystem management. We use three modelling protocols (i.e., maximum entropy, generalised linear model and generalised additive model) to predict the current distribution. Projections are made for both moderate (A1B) and extreme (A2) IPCC (Intergovernmental Panel on Climate Change) scenarios for the year 2050 and 2100. The study reveals that the distributions of C. tora (annual) and L. camara (perennial) would depend on the precipitation of the warmest quarter and moisture availability. C....
Understanding the patterns of biodiversity is central to species conservation planning. Here we i... more Understanding the patterns of biodiversity is central to species conservation planning. Here we illustrate chiropteran diversity and distribution pattern of the hill ranges of the Eastern Ghats of Odisha state, India using roost survey and mist net survey techniques. The present study recorded 23 bat species including two newly recorded species for the study site i.e., Hipposideros galeritus and Megaderma spasma. The bat capture rate was the highest in the moist deciduous forest describing higher bat populations compared with the places of human habitation. Utilities of 21 climate, three physiographic and two disturbance variables and species distribution modeling could reveal that the north-eastern part was more suitable for bat distributions than the southern part of the region. The climate, physiographic and disturbance variables were crucial in their distributions, where elevation and potential evapotranspiration were highly significant. Unlike other species, Taphozous melanopogon showed negative correlation with these variables. The mean diurnal temperature and precipitation seasonality have positive influence on bat distributions, indicating their resilience to seasonal precipitation changes and day time temperature fluctuations. The negative effect of temperature seasonality on the distribution of Pteropus giganteus could attribute to its vulnerability to climate change effects. The study provides inputs for monitoring the future spatio-temporal changes, suggesting long term conservation measures. It could generate basic information on the impacts of climate change on bat distribution in the future climate change scenario.
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