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

Latitudinal diversity gradients (LDGs) reflect the interplay of
historical, ecological, and evolutionary processes, but these drivers may
vary across landforms. Mountains, with steep elevational and climatic
gradients, may sustain different diversity dynamics than adjacent
lowlands, where human activities are often more intense. Using
distributional and phylogenetic data for 732 Odonata species across
eastern China, we compared taxonomic and phylogenetic LDGs between
mountains and lowlands and identified their environmental determinants.
Phylogenetic diversity was quantified using two complementary metrics:
mean pairwise distance (MPD), capturing basal-level phylogenetic
divergence, and mean nearest taxon distance (MNTD), reflecting tip-level
divergence. Odonata species richness and phylogenetic diversity both
declined significantly with latitude in mountains and lowlands. The
magnitude of these gradients was similar for species richness and tip
phylogenetic diversity, but basal phylogenetic diversity declined more
steeply in mountains, suggesting stronger constraints on ancient Odonata
lineages in montane environments. Random forest analysis revealed that
mean annual temperature is the consistent key driver of LDGs in mountains
and lowlands, whereas historical climate change had little effect on
either. Moreover, temperature seasonality plays a particularly important
role in shaping mountain LDGs, while human modification exerts a
disproportionate negative effect in lowlands, especially reducing basal
phylogenetic diversity. Our results show that Odonata display both
taxonomic and phylogenetic LDGs, which are largely similar in mountains
and lowlands of eastern China, yet the key factors driving these patterns
vary. Montane LDGs primarily reflects temperature seasonality, while
lowland LDGs are increasingly shaped by human disturbance superimposed on
climatic gradients. Overall, this study highlights the importance of
considering landform context when interpreting broad-scale biodiversity
patterns, and they emphasize the dual conservation challenge of
safeguarding climate-sensitive montane lineages while mitigating the
erosion of evolutionary heritage in heavily modified lowland ecosystems.