Regionalizing aquatic ecosystems based on the river subbasin taxonomy concept and spatial clustering techniques

Area of Science:

• Ecology
• Environmental Science
• Geography

Background:

• Aquatic ecoregions are increasingly vital for watershed-scale ecosystem management.
• Effective spatial units are crucial for understanding and managing aquatic ecosystems.

Purpose of the Study:

• To delineate aquatic ecoregions within the Taihu Lake watershed.
• To identify and characterize distinct aquatic ecosystems at Level I and Level II scales.
• To assess spatial heterogeneities in aquatic ecosystems.

Main Methods:

• Utilized regionalizing principles: land area, comprehensiveness, dominance, conjugation, and hierarchy.
• Employed elevation and drainage density for Level I ecoregions.
• Used land use, soil type, and slope for Level II subecoregions.
• Applied Geographic Information System (GIS) technology for spatial data analysis.
• Incorporated river subbasin taxonomy, spatial clustering, and manual methods for regionalization.

Main Results:

• The Taihu Lake watershed was divided into two Level I aquatic ecoregions (I1, I2) and five Level II subecoregions (II11, II12, II13, II21, II22, II23).
• Significant differences were observed in topography, socio-economic factors, water quality, and aquatic ecology between delineated ecoregions.
• Quantitative analysis revealed spatial variability in fish species, benthic density, biomass, and diversity indices.

Conclusions:

• The delineation successfully identified distinct aquatic ecoregions within the Taihu Lake watershed.
• The study underscores the significant spatial heterogeneity and uneven distribution of aquatic ecosystem characteristics.
• Findings provide a foundation for targeted aquatic ecosystem management strategies in the region.