Maharaj Krishan Pandit

Aim: Energy availability is often assumed to be a primary driver of variation in biodiversity across large‐scale environmental gradients such as elevation, but support for the role of energetic constraints is far from universal. Here, we assume that these variations in energy–richness relationships might arise from the degree of match between the scale of the response of organisms to energy (response scale) and the scale of the observation made (observation scale). Location: 41 mountain ecosystems worldwide, with detailed case studies on Dongling Mountain, China. Time Period: Contemporary. Major Taxa Studied: Trees, shrubs, herbs, ferns, birds, ants, bees, Lepidoptera, Coleoptera, Orthoptera, soil fauna, litter‐layer fauna, bacteria, fungi. Methods: First, we quantify the response scale on the basis of energy requirements, and then, we develop a general scaling model that explicitly describes how the scale matching between response and observation scale influences the predictive power of energy in determining elevational richness patterns; this model holds across taxonomic groups, trophic guilds, and ecosystems across mountains globally. Results: Global analyses strongly supported the model's prediction that scale matching determines the detectability of energy‐richness relationships. On Dongling Mountain, energy availability best explained richness patterns at the predicted response scales for trees, herbs, and litter fauna. Main Conclusions: Our model advances the understanding of montane biodiversity distributions by demonstrating the critical role of scale matching in energy–richness relationships. Our findings strongly support the existing mechanistic foundation for predicting biodiversity changes across spatial scales in montane ecosystems. The scale‐matching principle we identified is likely to be applicable to a wide range of taxa and other ecosystems where energy availability varies across scales.

Biochar utilisation as a soil enhancer has gathered considerable interest owing to its notable capacity to boost soil productivity, enhance carbon sequestration, and improve agricultural sustainability. Nonetheless, how biochar affects the soil microbiome, a key to soil health and ecological functioning, remains a contested subject. Given the critical role microbial communities play in maintaining soil health and functioning, variations in soil microbiota may have a substantial impact on soil fertility and stability. Despite a wealth of studies on the effects of biochar on soil microbial communities, the results demonstrate that the reaction of the microbiome to biochar varies greatly depending on the edaphic and biochar properties and other factors such as the experimental conditions and agricultural practices. Notably, different components of the soil microbiome may respond to soil/biochar properties in a unique way, which makes generalising the impacts of biochar on the soil microbiome a difficult task. In this review, we comprehensively examine the factors governing the impacts of biochar on the soil microbiome, especially in terms of its repercussions on microbial diversity, community structure, and functional dynamics, and the potential ramifications for agricultural productivity and environmental sustainability.

Mountains, which constitute the majority of global biodiversity hotspots, are most vulnerable to ecosystem collapse due to various natural and anthropogenic stressors. Notably, over 90% of geopolitical conflicts have unfolded in the regions with global biodiversity hotspots. The Himalaya, Tibet and Hengduan (HTH) mountains are apt examples where climate change meets geopolitical conflict and militarization. Here, I advance a fresh proposal and hope that the neighbouring nations could bring to bear the neutrality of transboundary conservation areas, as part of their diplomatic tools, to broker a lasting peace. The proposal advocates establishing a Greater Himalayan Peace Reserve (GHPR) for posterity and regional ecological and economic security. The proposed reserve embraces the HTH mountains embodying some of the most biodiverse regions of the earth. These mountains also play a central role in controlling regional climate, water security and agricultural productivity of South and Southeast Asia. The GHPR is envisaged to be a potential regional platform for conservation diplomacy, and a model foundational framework for global sustainability and peace.

Background: Soil microbial communities affect above-ground plant diversity and community composition by influencing plant growth performance. Several studies have tested the effect of soil bacterial microbiome on growth performance of native and invasive plants, but the influence of specific bacterial isolates has not been investigated. Here, we investigated the effects of soil bacterial exclusion by soil sterilization and by inoculation ofStreptomycesrhizobacterial isolates on the growth performance of native and invasiveProsopiscongeners.Results: Plant growth performance of invasiveP. juliflorawas significantly reduced when grown in sterilized soils, whereas nativeP. cinerariashowed enhanced growth performance in the sterilized soils. When grown in the soil inoculated with the specificStreptomycesisolate fromP. juliflora(PJ1), the growth performance of invasiveP. juliflorawas significantly enhanced while that of nativeP. cinerariaseedlings was significantly reduced. However, inoculation ofP. cinerariaandP. julifloraseedlings withStreptomycesisolate from the rhizosphere of nativeP. cineraria(PC1) had no significant effect on the growth performances either ofP. julifloraorP. cineraria.Conclusion: Our study reveals that invasive P. juliflora experiences positive feedback from the non-native soil bacterial community, while the native P. cineraria experiences negative feedback from its soil bacterial community. Our results provide fresh experimental evidence for the enemy release hypothesis, and further our understanding of the contrasting growth-promoting effects of differentially recruited microbial species belonging to the same genus (Streptomyces) in the rhizospheres of alien invasive and native plants.

As the two largest countries by population, China and India have pervasive effects on the ecosphere. Because of their human population size and long international boundary, they share biodiversity and the threats to it, as well as crops, pests and diseases. We ranked the two countries on a variety of environmental challenges and solutions, illustrating quantitatively their environmental footprint and the parallels between them regarding the threats to their human populations and biodiversity. Yet we show that China and India continue to have few co-authorships in environmental publications, even as their major funding for scientific research has expanded. An agenda for collaboration between China and India can start with the shared Himalaya, linking the countries’ scientists and institutions. A broader agenda can then be framed around environmental challenges that have regional patterns. Coordinated and collaborative research has the potential to improve the two countries’ environmental performance, with implications for global sustainability.

Invasive plants are known to alter the soil microbial communities; however, the effects of co-occurring native and invasive congeners on the soil bacterial diversity and their predictive metabolic profiles are not known. Here, we compared the rhizosphere bacterial communities of invasive Prosopis juliflora and its native congener Prosopis cineraria using high-throughput sequencing of the 16S rRNA gene. Unweighted Pair Group Method with Arithmetic mean (UPGMA) based dendrogram revealed significant variation in the communities of these co-occurring Prosopis species. Additionally, Canonical Correspondence Analysis (CCA) based on microbial communities in addition to the soil physiochemical parameters viz. soil pH, electrical conductivity, moisture content and sampling depth showed ~ 80% of the variation in bacterial communities of the rhizosphere and control soil. We observed that Proteobacteria was the predominant phylum of P. juliflora rhizosphere and the control soil, while P. cineraria rhizosphere was dominated by Cyanobacteria. Notably, the invasive P. juliflora rhizosphere showed an enhanced abundance of bacterial phyla like Actinobacteria, Chloroflexi, Firmicutes and Acidobacteria compared to the native P. cineraria as well as the control soil. Predictive metagenomics revealed that the bacterial communities of the P. juliflora rhizosphere had a higher abundance of pathways involved in antimicrobial biosynthesis and degradation, suggesting probable exposure to enemy attack and an active response mechanism to counter it as compared to native P. cineraria. Interestingly, the higher antimicrobial biosynthesis predicted in the invasive rhizosphere microbiome is further corroborated by the fact that the bacterial isolates purified from the rhizosphere of P. juliflora belonged to genera like Streptomyces, Isoptericola and Brevibacterium from the phylum Actinobacteria, which are widely reported for their antibiotic production ability. In conclusion, our results demonstrate that the co-occurring native and invasive Prosopis species have significantly different rhizosphere bacterial communities in terms of composition, diversity and their predictive metabolic potentials. In addition, the rhizosphere microbiome of invasive Prosopis proffers it a fitness advantage and influences invasion success of the species.