Unraveling Spatial Patterns and Drivers of Fish Ecological Uniqueness in Subtropical Streams

Area of Science:

• Ecology
• Conservation Biology
• Freshwater Ecology

Background:

• Beta-diversity (β-diversity) measures community compositional variation and can be split into local (LCBD) and species (SCBD) contributions.
• Most β-diversity studies focus on taxonomy, with limited research on functional diversity, hindering conservation applications.
• Anthropogenic disturbances introduce uncertainties in stream fish β-diversity.

Purpose of the Study:

• To explore drivers of multidimensional β-diversity in fish communities.
• To investigate relationships between β-diversity and landscape factors, local environments, community metrics, and functional traits.
• To understand factors influencing taxonomic and functional β-diversity in headwater streams.

Main Methods:

• Calculated local (LCBD) and species (SCBD) contributions to taxonomic (TLCBD, TSCBD) and functional (FLCBD, FSCBD) β-diversity.
• Analyzed relationships between β-diversity components and biological/environmental factors using fish abundance and functional traits.
• Assessed impacts of water temperature, substrate, and land use on fish community uniqueness.

Main Results:

• LCBD and SCBD were influenced by biological and environmental factors.
• Higher species abundance correlated positively with TLCBD and FLCBD.
• Anthropogenic land use and environmental changes negatively impacted TLCBD and FLCBD, reducing ecological uniqueness.

Conclusions:

• Ecological uniqueness at the taxonomic level corresponds to uniqueness at the functional level.
• Conservation efforts for SCBD should integrate species abundance and occupancy data.
• Prioritizing conservation and restoration requires understanding drivers of fish community β-diversity.