Data from: Invasive fish reshape biodiversity patterns in China’s freshwater lakes

Globalization has dramatically accelerated the spread of non-native
species, intensifying threats to freshwater ecosystems. While China ranks
among the most heavily invaded countries, the role of non-native species
as key drivers of biodiversity changes is often overlooked in research on
anthropogenic impacts. This oversight hampers the development of effective
conservation and management strategies by limiting a full understanding of
what shapes biodiversity patterns. To bridge this gap, an extensive
dataset from 131 lakes across China was compiled and analyzed using a
novel composite diversity index that integrates species richness with
functional and phylogenetic uniqueness, allowing for a more precise
identification of fish multidimensional diversity hotspots. Additionally,
gradient forest models were employed to elucidate the impacts of
non-native species, geography, climate, and physicochemical factors on
these patterns. Our findings revealed significant taxonomic and functional
homogenization in non-native hotspots within the overall fish community,
coupled with phylogenetic diversification. Notably, non-native fish
diversity emerged as the primary factor shaping overall and native fish
multidimensional diversity patterns. While the establishment of non-native
species may provide an immediate enhancement to overall diversity, it
often leads to the extirpation/extinction of native species, ultimately
resulting in biodiversity loss at local and potentially the regional
scale. This study highlights the importance of examining multiple
dimensions to characterise the intricate dynamics between native and
non-native species, which is essential for understanding their true impact
on biodiversity and for achieving global conservation goals.