Dealing with disjunct populations of vascular plants: implications for assessing the effect of climate change

Abstract

Species distribution models are the most widely used tool to predict species distributions for species conservation and assessment of climate change impact. However, they usually do not consider intraspecific ecological variation exhibited by many species. Overlooking the potential differentiation among groups of populations may lead to misplacing any conservation actions. This issue may be particularly relevant in species in which few populations with potential local adaptation occur, as in species with disjunct populations. Here, we used ecological niche modeling to analyze how the projections of current and future climatically suitable areas of 12 plant species can be affected using the whole taxa occurrences compared to occurrences from geographically disjunct populations. Niche analyses suggest that usually the disjunct group of populations selects the climatic conditions as similar as possible to the other according to climate availability. Integrating intraspecific variability only slightly increases models’ ability to predict species occurrences. However, it results in different predictions of the magnitude of range change. In some species, integrating or not integrating intraspecific variability may lead to opposite trend in projected range change. Our results suggest that integrating intraspecific variability does not strongly improve overall models’ accuracy, but it can result in considerably different conclusions about future range change. Consequently, accounting for intraspecific differentiation may enable the detection of potential local adaptations to new climate and so to design targeted conservation strategies.

Possible extinction of Eversmannia subspinosa in Eastern Alborz by 2060 due to climate change: A MaxEnt study

“…Chardon et al (2023) found that microhabitat variables weakly predict recruitment and seedling survival, with varied responses to environmental factors across species and life stages (Chardon et al, 2023). Adding to this complexity, a recent research has highlighted the importance of considering intraspeci c ecological variation when predicting species distributions for conservation and climate change impact assessment (Varaldo et al, 2023).…”