Developing a European aquatic macrophyte transfer function for reconstructing past lake-water chemistry.

Area of Science:

• Paleolimnology
• Aquatic Ecology
• Paleoenvironmental Reconstruction

Background:

• Biological proxies like diatoms have advanced paleolimnology, but macrophytes are underutilized for reconstructing past lake-water chemistry.
• Understanding past environmental changes is crucial for effective nature conservation and ecological restoration.

Purpose of the Study:

• To identify the key environmental variable explaining aquatic plant community composition in Northern European lakes.
• To develop quantitative methods for reconstructing past lake-water conductivity and alkalinity using macrophyte assemblages.

Main Methods:

• Created a modern macrophyte-environment calibration dataset across Finnish, Polish, and Swedish lakes.
• Calculated modern calibration functions using simple averaging regression.
• Reconstructed past environmental conditions in Lake Linówek using weighted averaging calibration on fossil assemblages.

Main Results:

• Conductivity and alkalinity were the strongest predictors of macrophyte community composition.
• Species' carbon concentrating mechanisms influenced their alkalinity optima.
• Paleoenvironmental reconstructions revealed fluctuations in conductivity and alkalinity throughout the Late Glacial and Holocene periods.

Conclusions:

• Macrophytes are effective indicators for reconstructing past lake-water chemistry, particularly conductivity and alkalinity.
• Developed calibration functions can support nature conservation by defining habitat requirements for endangered macrophyte species.
• This method provides a valuable tool for understanding long-term lake dynamics and informing conservation strategies.