Abstract
Studying long-term dynamic of critically endangered species, such as quillworts (Isoëtes lacustris, Isoëtes echinospora) is crucial for maintaining biodiversity and developing management strategies that preserves their natural habitat. Local quillwort populations have slowly diminished since the Last Ice Age and are thus considered endangered in many European countries.
Based on direct observation and field experiments, many recent ecological studies have proposed several hypothetical causes of the decline in quillwort populations across Europe. Unfortunately, long-term studies investigating quillwort dynamics from the Holocene are rare.
The aim of this study is to reconstruct postglacial dynamics of quillwort populations using a multi-proxy approach including plant macrofossils, pollen, diatoms, and geochemistry to investigate the long-term occurrence of, and drivers related to their recent extinction in Prášilské lake, Bohemian Forest. Our preliminary results show that quillwort have persisted but with high variation in Prášilské lake since 10400 cal yr BP.
Around 4000 cal yr BP, there was a substantial decline in quillwort microspore and macrospore concentrations. This trend seems to be connected with a shift to more eutrophic status of water chemistry as supported by changes in diatom assemblages.
Unfortunately, in 1969 the species became extinct locally. While these results are preliminary, the results of this long-term record could serve as a useful template for management towards implementing strategies that will preserve their natural habitat.