Functional Dimension Reveal Impacts of Non-Native Fishes on Native Fishes and Ecosystem Functionality

Area of Science:

• Ecology
• Invasive Species Biology
• Conservation Science

Background:

• Anthropogenic activities drive non-native species invasions, causing biodiversity loss and impacting ecosystem functions.
• Long-term effects of non-native species on native biodiversity and ecosystem multifunctionality remain poorly understood, especially concerning functional and phylogenetic diversity.

Purpose of the Study:

• To assess the long-term impact of non-native fishes on the multidimensional diversity of native fishes in Lake Erhai, China.
• To investigate the cascading effects of these invasions on ecosystem multifunctionality, including productivity and decomposition.

Main Methods:

• Utilized an 80-year dataset from Lake Erhai, China, to analyze fish community structure, functional diversity, and phylogenetic diversity.
• Correlated changes in non-native and native fish diversity with trends in ecosystem multifunctionality metrics.
• Examined trait spaces and community patterns using a convergence-divergence-convergence framework.

Main Results:

• Non-native fish diversity increased significantly over time, while native fish diversity declined markedly.
• Ecosystem productivity and average multifunctionality showed significant upward trends, correlating positively with non-native fish functional diversity.
• Native fish functional diversity and environmental factors were negatively associated with ecosystem multifunctionality.

Conclusions:

• Long-term non-native fish invasions negatively impact native fish multidimensional diversity.
• While non-native species can initially increase ecosystem multifunctionality, this effect may diminish at higher invasion levels.
• Integrating functional perspectives into biodiversity monitoring is crucial for managing invasive species impacts on native ecosystems.