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Background: Large-scale changes in habitat conditions due to human modifications and climate change require management practices to consider how species communities can alter amidst these changes. Understanding species interactions across the gradient of space, anthropogenic pressure, and season provide the opportunity to anticipate possible dynamics in the changing scenarios. We studied the interspecific interactions of carnivore species in a high-altitude ecosystem over seasonal (summer and winter) and resource gradients (livestock grazing) to assess the impact of changing abiotic and biotic settings on coexistence. Methods: The study was conducted in the Upper Bhagirathi basin, Western Himalaya, India. We analyzed around 4 years of camera trap monitoring data to understand seasonal spatial and temporal interactions of the snow leopard with common leopard and woolly wolf were assessed in the greater and trans-Himalayan habitats, respectively. We used two species occupancy models to assess spatial interactions, and circadian activity patterns were used to assess seasonal temporal overlap amongst carnivores. In addition, we examined scats to understand the commonalities in prey selection. Results: The result showed that although snow leopard and wolves depend on the same limited prey species and show high temporal overlap, habitat heterogeneity and differential habitat use facilitate co-occurrence between these two predators. Snow leopard and common leopard were spatially independent in the summer. Conversely, the common leopard negatively influences the space use of snow leopard in the winter. Limited prey resources (lack of livestock), restricted space (due to snow cover), and similar activity patterns in winter might result in strong competition, causing these species to avoid each other on a spatial scale. The study showed that in addition to species traits and size, ecological settings also play a significant role in deciding the intensity of competition between large carnivores. Climate change and habitat shifts are predicted to increase the spatial overlap between snow leopard and co-predators in the future. In such scenarios, wolves and snow leopards may coexist in a topographically diverse environment, provided sufficient prey are available. However, shifts in tree line might lead to severe competition between common leopards and snow leopards, which could be detrimental to the latter. Further monitoring of resource use across abiotic and biotic environments may improve our understanding of how changing ecological conditions can affect resource partitioning between snow leopards and predators. [ABSTRACT FROM AUTHOR]

Contamination of soil and water with explosive compounds like octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX or commonly known as high melting explosives) is increasing day by day due to their extensive use all over the world. High level of contamination has been found near military sites, explosive manufacturing facilities, war-lands, mines and exercise ranges. Remediation of such contaminants is necessary as they may have adverse impact on biotic as well as on abiotic environment. Present study was carried out with an objective to optimize the variable process parameters for the degradation of HMX in aqueous phase by indigenously isolated bacterial strain, Bacillus toyonensis from an actual HMX contaminated site in North India using response surface methodology. The relationship among varying initial concentrations of HMX, microbial inoculum size and degradation time was revealed in the current study. Results showed that 87.7% degradation was achieved at 2 mg/L initial HMX concentration with inoculum size of 4% on 15th day. High regression coefficient value (0.9878) further supported predictability of experimental data. Nitrite and nitrate concentrations estimated during the experiment indicate breakdown and degradation process of HMX. Findings of this study concluded that Bacillus toyonensis can be a potential microorganism to degrade HMX and can be used for microbial remediation of HMX contaminated sites. [ABSTRACT FROM AUTHOR]

The fish productivity from the reservoir in its all naturalness depends on various abiotic and biotic factors. The abiotic factors include mostly all physico-chemical parameters of water body, which have immense influence on biogenic factors and existence of flora and fauna in the reservoir. The first and foremost impact of physico-chemical parameters are experienced by the biotic community existing at the base of trophic level, which include the autotrophs like phytoplankton, which forms the very basic source of food material for the first order consumers like fishes who thrive on the pasture of phytoplankton. The physical factors like insolation, temperature, transparency had the direct impact on the existence of phytoplankton. The results obtained clearly indicates the existence of high bloom of plankton in the summer months owing to increased availability of radiant sun's energy (insolation), rise in temperature and high level of transparency accounting for the enhanced photosynthetic activity. The astonishingly high bloom phytoplankton at all the stations of the recording in the summer ensured the ample availability of food material for pelagic fishes. The length-weight measurement conducted for all the fishes from the reservoir evidently indicated the maximum gain of the growth of fishes during the summer months. The community, which derived the maximum advantage of high intensity of feeding on phytoplankton during the summer months resulting into enhanced growth, was mostly the carps (Indian major carps and minor carps) from the reservoir. The correlation of finding of fish fecundity in the reservoir to the conversion eggs into spawns at the rate of minimum 50%, it was estimated that there was addition of average number of over 20.0 Lakh from Catla catla; over 30.0 Lakh from Labeo rohita, over 20.0 Lakh of Cirrhinus mrigala, over 15.0 Lakh from Heteropneustes fossilis and Channa striatus, over 35.0 Lakh Labeo gonius. [ABSTRACT FROM AUTHOR]

Water quality analysis involves analysis of physio-chemical, biological and microbiological parameters that reflect the abiotic and biotic status of ecosystems. This assessment facilitates planning for the utilization, antipollution and conservation strategies for sustainable use of aquatic ecosystem. Many mathematical models are available for predicting water quality. They have complex structures and require detailed information about sources and receptors, which are difficult and non-economical. Difficulties in applying mathematical models promote the application of alternative approaches for data-driven techniques for analysis of the results. The present study focuses on water quality predictions for the Gangapur Reservoir for a 30 days in advance scenario, using genetic programming ( GP) and least square support vector machines ( LS- SVMs). A data period of 11 years (2000-2011) of Gangapur Reservoir temporal water quality was evaluated. The data were taken from a single sampling point representing climatological, hydrological and surface water quality measurements. One of the most important steps in application of data-driven technique is selection of significant input parameters. Genetic programming equations were used for selecting significant input parameters. These significant input parameters are used for 30 days advance predictions of faecal coliform. A performance analysis of GP and LS- SVM models was carried out with the help of coefficient of determination, root-mean-square error and correlation coefficient. In the absence of availability of data, a typical situation for Indian case studies, the model runs were conducted with the use of available parameters. The developed models, along with their performance indicators, also are discussed. [ABSTRACT FROM AUTHOR]

The rapid growth of cities—along with the increasing connectedness of the world's social, economic, and political systems—has been hypothesized to generate a homogenization of urban form and associated environmental impacts. These hypotheses, however, have rarely been tested. Employing satellite imagery of 150 of the most populous cities in China, India, and the United States, we examine how the area and configuration of built-up land within cities has changed between 1995 and 2015 and assess impacts on the urban heat island effect. We find similar urban form trends across the three countries. The strongest evidence of homogenization is in the connectivity of urban form, while the shape of cities is linked to higher daytime surface urban heat island (SUHI) intensity. In the context of this and other research, we postulate that the identified urban form trends may lead to the homogenization of the biotic and abiotic environment of cities. Homogenization presents an opportunity for cities to learn from each other as they encounter similar ecological outcomes driven, in part, by their increasingly similar urban form. • Populous cities in China, India, and the U.S. have similar trends in urban form. • Urban form exhibits a homogenizing trend for connectivity. • Increasing shape compactness and complexity are linked with increasing SUHI intensity. • If urban form homogenizes, cities can expect similar SUHI consequences. [ABSTRACT FROM AUTHOR]

Over the last five decades, inter-tidal ecology has evolved from being a purely descriptive science to using quantitative and experimental approaches to understand community structure. However, this has sometimes come at the cost of understanding generality since many studies have focused on local spatial scales and patch dynamics. This study aimed to assess the generality of co-occurrence patterns at a large spatial scale, covering over 1000 km, by comparing empirical association patterns with random patterns generated by simulations. Species co-occurrence patterns are useful to examine the role of abiotic and biotic factors in community assembly. Our results show non-random patterns of species association at large spatial scales, mainly reflecting increasing community similarity with decreasing geographical distance, although random patterns of species association were found at the smallest spatial scales. Negative associations between species dominated the association pattern when all species pairs were considered, but most of the significant associations were positive. There was low congruence of association strengths of the same species-pairs in different clusters, indicating that associations are likely to be contingent on local conditions. Finally, association strength of con-familial species pairs was found to be higher than species belonging to different families, probably reflecting habitat filtering. This study emphasizes the role and importance of examining general patterns and of using a combination of experimental and observational studies to gain insights at multiple scales. [ABSTRACT FROM AUTHOR]

Partitioning beta diversity into its two components of spatial turnover and nestedness is a more robust method for checking spatial variability in biological communities than calculating the total beta diversity alone. The relative contribution of spatial turnover and nestedness has been used to test the effects of climatic, environmental, spatial and temporal variables on community composition. In this study, we tested the effects of environmental factors and microhabitat features on total beta diversity and its spatial turnover and nestedness components using a comprehensive dataset of aquatic Heteroptera collected from four types of permanent freshwater habitats (i.e. streams, ponds, rock tanks and reservoirs) in the Western Ghats of India. We observed that communities in all four types of habitats were predominantly shaped by dissimilarity caused due to spatial turnover (>85 %). Each type of habitat showed the presence of one or more species uniquely associated with it, which might contribute to the turnover between communities. The abiotic environment (climatic factors, topological factors, soil characteristics and microhabitat features) as well as assemblage structure differed significantly between habitat types. Communities in each type of habitat were affected by different environmental factors, such as precipitation and temperature patterns for streams, altitude and rocky substrate for rock tanks, and soil characteristics and the presence of aquatic macrophytes for ponds and reservoirs. Assemblages observed in the four types of permanent habitats are thus compositionally distinct due to species replacements between local communities, which in turn are strongly influenced by environmental variables. Similar to previous studies, our results show that spatial turnover largely measures the same phenomenon as total beta diversity on a regional scale. [ABSTRACT FROM AUTHOR]