Data from: Reconstructing long-term human impacts on plant communities: an ecological approach based on lake sediment DNA

Paleoenvironmental studies are essential to understand biodiversity changes over long timescales and to assess the relative importance of anthropogenic and environmental factors. Sedimentary ancient DNA (sedaDNA) is an emerging tool in the field of paleoecology and has proven to be a complementary approach to the use of pollen and macroremains for investigating past community changes. SedaDNA-based reconstructions of ancient environments often rely on indicator taxa or expert knowledge, but quantitative ecological analyses might provide more objective information. Here, we analysed sedaDNA to investigate plant community trajectories in the catchment of a high-elevation lake in the Alps over the last 6400 years. We combined data on past and present plant species assemblages along with sedimentological and geochemical records to assess the relative impact of human activities through pastoralism, and abiotic factors (temperature and soil evolution). Over the last 6400 years, we identified significant variation in plant communities, mostly related to soil evolution and pastoral activities. An abrupt vegetational change corresponding to the establishment of an agropastoral landscape was detected during the Late Holocene, approximately 4500 years ago, with the replacement of mountain forests and tall-herb communities by heathlands and grazed lands. Our results highlight the importance of anthropogenic activities in mountain areas for the long-term evolution of local plant assemblages. SedaDNA data, associated with other paleoenvironmental proxies and present plant assemblages, appear to be a relevant tool for reconstruction of plant cover history. Their integration, in conjunction with classical tools, offers interesting perspectives for a better understanding of long-term ecosystem dynamics under the influence of human-induced and environmental drivers.

古环境研究对于理解长时间尺度下的生物多样性变化，以及评估人类活动与环境因素的相对重要性至关重要。沉积古DNA（sedimentary ancient DNA, sedaDNA）是古生态学领域的新兴研究手段，已被证实可作为孢粉与大化石研究的互补方法，用于探究过去的群落变迁。基于沉积古DNA的古环境重建通常依赖指示类群或专家经验，但定量生态学分析可提供更为客观的研究结果。本研究通过沉积古DNA分析，探究了过去6400年间阿尔卑斯山区某高海拔湖泊流域内的植物群落演替轨迹。本研究整合了古今植物物种组合数据，以及沉积学与地球化学记录，以评估放牧等人类活动以及温度、土壤演化等非生物因素的相对影响。在过去6400年中，研究团队观测到植物群落发生了显著变化，其主导驱动因素为土壤演化与放牧活动。约4500年前的全新世晚期，研究团队检测到一次植被突变事件，对应农牧混合景观的形成：山地森林与高大草本群落被灌丛与放牧草地取代。本研究结果凸显了山地人类活动对当地植物群落长期演化的重要意义。沉积古DNA数据结合其他古环境代用指标与现代植物群落数据，可作为重建植被覆盖历史的有效工具。将其与传统研究手段相结合，可为深入理解人类活动与环境驱动因子影响下的长期生态系统动态提供极具价值的研究视角。