Work

Climatic drivers prevail in montane and lowland Odonata latitudinal diversity gradients, but human modification erodes lowland patterns

Year: 2026

Type: article

Abstract: Latitudinal diversity gradients (LDGs) arise from the interplay of historical, ecological, and evolutionary processes, yet these drivers may differ across landforms. Mountains, with steep elevational and climatic gradients, often sustain distinct diversity dynamics compared with adjacent lowlands, where vertical climatic gradients are weak and human pressures stronger. However, how the patterns and underlying drivers of LDGs differ between mountains and lowlands remains poorly understood. We used distributional and phylogenetic data for 732 Odonata species across eastern China to compare taxonomic and phylogenetic LDGs between mountains and lowlands, and to identify the environmental drivers underlying these patterns. Phylogenetic diversity was quantified using mean pairwise distance (MPD) and mean nearest taxon distance (MNTD), which reflect lineage relatedness at basal and tip levels, respectively. Our results revealed that Odonata species richness and phylogenetic diversity declined significantly with latitude in mountains and lowlands. The slopes of LDGs were similar for species richness and tip phylogenetic diversity, whereas basal phylogenetic diversity showed a steeper decline in mountains than in lowlands. Random forest analysis revealed that current climatic conditions, such as mean annual temperature, are the key driver of LDGs in both mountains and lowlands, whereas historical climate change had little effect on either landform. Moreover, temperature seasonality played a particularly important role in shaping mountain LDGs, while human pressure exerted a significant negative effect in lowlands, particularly by reducing basal phylogenetic diversity. Overall, our results highlight the dual conservation challenge of safeguarding climate‐sensitive montane lineages while mitigating the loss of evolutionary heritage in heavily modified lowland ecosystems, and underscore the role of topography in shaping large‐scale biodiversity patterns.

Source: Ecography

DOI: 10.1002/ecog.08479

Authors: Zhenyuan Liu, Bo‐Ping Han, Haomiao Zhang, Ramiro Martín‐Devasa, Jens‐Christian Svenning, Janne Soininen