Anthropogenic-mediated invasions of non-native species are leading to biodiversity loss in many trophic groups However, the impacts of non-native species on native species and ecosystem multifunctionality are not well understood, particularly due to the lack of studies focusing on the analysis of functional and phylogenetic diversities.

In a study published in Global Change Biology, researchers from the Institute of Hydrobiology of the Chinese Academy of Sciences conducted analyses in Lake Erhai as a case study of non-native fish invasion, elucidated temporal relationships between lake fish multidimensional diversity and ecosystem multifunctionality, and revealed the key role of non-native fishes.

Researchers found a persistent increase in non-native fish diversity alongside a marked decline in native fish diversity, indicating an observed significant negative correlation between non-native and native fish. 

Then, they found that non-native fish functional diversity exhibited a nonlinear relationship with ecosystem multifunctionality, which showed positive effects at low levels and negative effects at high levels, and that native fish functional diversity and environmental factors such as water level, transparency, and precipitation were negatively correlated with multifunctionality.

Using null models, researchers obtained standardized effect sizes for each decade to infer mechanisms underlying community assembly. They found that the functional space of fish assemblages, and their functional and phylogenetic structures, exhibited a dynamic convergence-divergence-convergence pattern, reflecting long-term impacts of non-native fish invasions on lake ecosystem structure and functioning.

The findings of this study underscore the importance of integrating functional perspective in biodiversity monitoring and management to enhance our understanding of long-term impacts of non-native species on native species and ecosystem multifunctionality.