Ground vegetation cover at 47 lake sites in Central and Eastern Yakutia, Siberia, in summer 2021 (RU-Land_2021_Yakutia)

The vegetation surveys were carried out in four different study areas in the Sakha Republic, Russia: in the mountainous region of the Verkhoyansk Range within the Oymyakonsky and Tomponsky District (Event EN21402 - EN21415), and in three lowland regions of Central Yakutia within the Churapchinsky, Tattinsky and the Megino-Kangalassky District (Event EN21416 - EN21464). The study area is located within the boreal forest biome that is underlain by permafrost soils. The aim was to record the projective ground vegetation in the shore area of the lakes studied during the RU-Land_2021_Yakutia summer field campaign in August and September 2021. Baisheva et al. (2022) gives an overview of the lakes studied and the corresponding hydrochemistry.
The ground vegetation was estimated as a percentage within 2 x 2 m plots. The location of the plots was selected on site at the lake to represent the typical ground cover. Some of the vegetation plots were located directly on the shore in the transition to the water, others were chosen nearby the lakeshore. The elevation corresponds to the lake level, as the plots were in the immediate vicinity.
The number of plots per lake depended on the different land cover classes, with more plots selected if the vegetation cover was more heterogeneous. The vegetation cover was estimated for each taxon within the plot. If only a few specimens of a species were represented within the plot (less than 1%), they are marked with '< 1'. If many specimens of a species were represented in a plot (up to 5%), they are designated as '< 5'. Mainly the ground vegetation was recorded. In case of clear height difference of the plants in a plot, the cover was divided into shrubs (approx. > 1.70 m) and trees (> 3-5 m).
In total, 92 plots at 47 lakes were investigated. All data were collected by scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) Germany, the University of Potsdam Germany, and the North-Eastern Federal University of Yakutsk (NEFU) Russia.

本植被调查于俄罗斯萨哈共和国（Sakha Republic）的四个不同研究区域开展：分别位于奥伊米亚康区和托姆蓬斯基区境内的维尔霍扬斯克山脉山地（对应事件编号EN21402 - EN21415），以及楚拉普钦斯基区、塔京斯基区与梅吉诺-坎加拉西基区境内的雅库特中部三大低地区域（对应事件编号EN21416 - EN21464）。
研究区域处于寒温带针叶林生物群区（boreal forest biome），其下分布永久冻土土壤（permafrost soils）。本次调查的目标是记录2021年8月至9月RU-Land_2021_Yakutia夏季野外考察期间，所研究湖泊岸带的投影植被盖度。Baisheva等人（2022）对本次研究涉及的湖泊及其对应的水化学特征进行了综述。
地表植被盖度以2×2米样方内的百分比进行估算。样方点位于湖泊现场选取，以代表典型的地表覆被状况。部分植被样方直接设置于与水体过渡的湖岸带，其余则布设于湖岸附近。由于样方紧邻湖泊，其海拔与湖面高程基本一致。
每个湖泊的样方数量取决于土地覆被类型的多样性，植被盖度异质性越强则布设的样方数量越多。需对样方内每个分类单元（taxon）的植被盖度进行估算。若样方内某物种仅存在少量个体（盖度<1%），则标记为“< 1”；若个体数量较多但盖度不超过5%，则标记为“< 5”。本次调查主要记录地表植被，若样方内植物存在明显高度分层，则将植被划分为灌木（约>1.70米）和乔木（>3-5米）两类分别估算盖度。
本次研究共对47个湖泊的92个样方进行了调查。所有数据由德国阿尔弗雷德·魏格纳研究所、亥姆霍兹极地与海洋研究中心（Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, AWI）、德国波茨坦大学，以及俄罗斯雅库茨克东北联邦大学（North-Eastern Federal University of Yakutsk, NEFU）的科研人员采集完成。