This study of the Kanna calcareous spring fen on Saaremaa, the largest island of Estonia, elucidates its history of fen development and vegetation diversity over the last 9,200 years. Pollen, spores, non-pollen palynomorphs, macrofossils, loss-on-ignition and humification index analyses were carried out to reconstruct fen succession, vegetation development, environmental changes and human impact. Hierarchical clustering, ordination analysis and linear regression were applied to examine the vegetation composition and richness patterns through time and to identify the potential environmental drivers underlying these patterns. Our results suggest reverse mire development from bog to fen, a rare occurrence and contrary to typical mire autogenic succession from groundwater fed to rainwater fed. Kanna developed as a small bog for the first 2,000 years from 9,200 to 7,200 cal yrs bp. Changes to the hydrological regime around 7,200 cal yrs bp, due to a warmer and drier climate and land uplift, caused a change from an ombrotrophic to a minerotrophic environment. Typical spring fen characteristics developed ca. 5,000 cal yrs bp and continued until ca. 400 cal yrs bp, when the fen was fed by calcareous mineral-rich groundwater and reached very high floristic diversity with various calciphilous and relict plant taxa. We conclude that general changes in the Kanna fen succession, vegetation community and diversity are associated with climatic changes. The present high diversity of the fen is a result of a long-term stable fen environment, which may have been even higher in the past. However, the pollen richness has decreased during the last 400 years, possibly due to human or natural factors.

中文翻译：

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从沼泽到芬：爱沙尼亚萨列马岛钙质春季芬发育的古生态重建

这项对爱沙尼亚最大岛屿萨勒马岛的卡纳钙质春季spring的研究阐明了近9200年以来其发展和植被多样性的历史。进行了花粉，孢子，非花粉状单孢粉，大型化石，点火损失和增湿指数分析，以重建reconstruct的演替，植被发育，环境变化和人类影响。应用层次聚类，排序分析和线性回归来检查植被组成和丰富度模式随时间的变化，并确定这些模式背后的潜在环境驱动因素。我们的研究结果表明泥潭从沼泽到reverse的逆向发展，这种情况很少见，这与从地下水到雨水的典型泥潭自生演替相反。卡纳（Kanna）在最初的2年发展成小沼泽bp。由于气候变暖和干燥以及土地隆升，大约7200 cal yrs bp的水文状况发生了变化，从而导致了从营养营养环境到矿物营养环境的变化。约有典型的春芬特性。5,000 cal yrs bp，一直持续到大约 400 CAL年BP，当the由富含钙质矿物质的地下水喂养时，由于各种钙质和遗留植物类群而达到很高的植物多样性。我们得出结论，卡纳芬演替，植被群落和多样性的总体变化与气候变化有关。芬的当前高度多样性是长期稳定的芬环境的结果，过去这种环境可能更高。但是，花粉丰富度在过去400年中有所下降，这可能是由于人为因素或自然因素造成的。