Ecological assessment and environmental niche modelling of Himalayan rhubarb (Rheum webbianum Royle) in northwest Himalaya

Abstract

In an era of anthropocene, threatened and endemic species with small population sizes and habitat specialists experience a greater global conservation concern in view of being at higher risk of extinction. Predicting and plotting appropriate potential habitats for such species is a rational method for monitoring and restoring their dwindling populations in expected territories. Ecological niche modelling (ENM) coalesces species existence sites with environmental raster layers to construct models that describe possible distributions of plant species. The present study is aimed to study the potential distribution and cultivation hotspots for reintroducing the high value, vulnerable medicinal herb (Rheum webbianum) in the Union territories of Jammu and Kashmir and Ladakh using population attributes and ecological niche modelling approach. Sixty-three populations inventoried from twenty-eight areas display a significant change in the phytosociological attributes on account of various anthropogenic threats. The current potential habitats coincide with actual distribution records and the mean value of Area Under Curve (AUC) was 0.98 and the line of predicted omission was almost adjacent to omission in training samples, thus validating a robustness of the model. The potential habitat suitability map based on the current climatic conditions predicted a total of 103760 km2 as suitable area for the growth of Rheum webbianum. Under the future climatic conditions, there is a significant reduction in the habitat suitability ranging from -78531.34 Km2 (RCP 4.5 for 2050) to -77325.81 (RCP 8.5 for 2070). Furthermore, there is a slight increase in the suitable habitats under future climatic conditions, ranging from +21.99 Km2 under RCP 8.5 (2050) to +3.14 Km2 under RCP 4.5 (2070). The Jackknife tests indicated Precipitation of Driest Month (BIO14) as the most contributing climatic variable in governing the distribution of R. webbianum. Therefore, scientifically sound management strategies are urgently needed to save whatever populations are left in-situ to protect this species from getting extinct. Present results can be used by conservationists for mitigating the biodiversity decline and exploring undocumented populations of R. webbianum on one hand and by policymakers in implementing the policy of conservation of species with specific habitat requirements by launching species recovery programmes in future on the other.

Modelling ecological niches of Sclerocarya birrea subspecies in Tanzania under the current and future climates

“…multifoliata occurs, where there are unimodal rains. Our study findings on contraction of ecological niches of S. birrea subspecies under future climates are in accordance with other studies (Djotan et al 2018;Bogawski et al 2019;Gebrewahid et al 2020) and Wani et al (2021). Despite having physiological traits that make them drought-tolerant according to Hall et al (2002) and Jinga et al (2021), the current ecological niches of the S. birrea subspecies will probably shift but are unlikely to expand under future warming climates.…”

Modeling potential distribution of newly recorded ant, Brachyponera nigrita using Maxent under climate change in Pothwar region, Pakistan

“…Our calculated AUC value shows that the results are significant (0.930) ( Fig 4A ). AUC value was considered as best and significant on the basis of knowledge based on previous studies [ 55 , 56 ]…”

Anthropogenic impacts drive habitat suitability in South Asian bats

“…Hence, a combined appraisal of both types of ecological predictors is necessary. However, the large impacts that climate factors have on bats (Festa et al, 2022) may outweigh the speci c impact patterns of ecogeographic factors (Wani et al, 2021), motivating an approach that models climate and ecogeography separately and combines the outputs of these models into summary models using boolean comparisons. Separate-then-compare niche modelling analyses could also provide insight into species-level and consensus spatial patterns in ecogeographic and climatic suitability -species are likely to respond differently to ecogeographic and climatic conditions.…”