Temperature transfer functions based on freshwater testate amoebae from China

Area of Science:

• Ecology
• Environmental Science
• Microbiology

Background:

• Global warming impacts lake and reservoir ecosystems, particularly in the Northern Hemisphere.
• Testate amoebae are sensitive indicators of environmental change in aquatic systems.

Purpose of the Study:

• To investigate the relationship between testate amoebae communities and environmental variables in Chinese lakes and reservoirs.
• To develop transfer functions for reconstructing past water temperatures using testate amoebae data.

Main Methods:

• Analysis of testate amoebae communities and 10 environmental variables from 51 lakes and reservoirs.
• Development of abundance- and biomass-based transfer functions for temperature using Weighted Averaging-Partial Least Squares (WA-PLS) and Modern Analog Technique (MAT).
• Partial Canonical Correspondence Analysis (CCA) to determine the influence of water temperature on testate amoebae communities.

Main Results:

• 169 testate amoebae taxa were identified.
• Water temperature explained a significant portion of the variance in testate amoebae abundance (5.15%) and biomass (5.57%).
• WA-PLS and MAT models showed good performance for abundance-based (RMSEP = 2.87°C, R² = 0.60) and biomass-based (RMSEP = 3.34°C, R² = 0.67) temperature reconstructions, respectively.

Conclusions:

• Freshwater testate amoebae are valuable bioindicators for assessing the ecological integrity and vulnerability of inland aquatic environments.
• Transfer functions developed in this study can aid in reconstructing past thermal conditions in lakes and reservoirs.
• Further research is needed to refine the application of these models for accurate paleoclimate reconstructions.