Images of ground vegetation at 58 sites in Central and Eastern Yakutia, in Summer 2021 (RU-Land_2021_Yakutia)

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 EN21-201 - EN21-219), and in three lowland regions of Central Yakutia within the Churapchinsky, Tattinsky and the Megino-Kangalassky District (Event EN21220 - EN21264). 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 different boreal forest types studied during the RU-Land_2021_Yakutia summer field campaign in August and September 2021. Ground vegetation was photographed for different vegetation types within a circular forest plot of 15m radius. Depending on the heterogeneity of the forest plot, multiple vegetation types (VA, VB, or VC) were chosen for the survey. Up to four quadrats (2mx2m) were surveyed and photographed for each vegetation type. The centre of the circular plot was surveyed additionally. Up to four photos in landscape orientation were taken of each quadrat. In total, 328 quadrats or plot centres at 58 forest plots were photographed. All data were collected by scientists form the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) Germany, the University of Potsdam Germany, and the North-Easter Federal University of Yakutsk (NEFU) Russia.本研究于俄罗斯萨哈共和国（Sakha Republic）的4个不同研究区域开展植被调查：分别位于奥伊米亚康区（Oymyakonsky District）与通波西区（Tomponsky District）境内的维尔霍扬斯克山脉（Verkhoyansk Range）山地（对应事件编号EN21-201至EN21-219），以及丘拉普钦斯基区、塔廷斯基区与梅吉诺-坎加拉斯基区境内的雅库特中部3处低地（对应事件编号EN21220至EN21264）。上述研究区域均处于以永久冻土为基底的北方森林生物群区（boreal forest biome）内。本次调查的目标为记录2021年8-9月开展的RU-Land_2021_Yakutia夏季野外考察中涉及的各类北方森林类型的地面植被投影盖度。 针对半径15米的圆形森林样地内的不同植被类型，科研人员对其地面植被进行拍摄。根据森林样地的异质性特征，本次调查选取了VA、VB或VC等多种植被类型开展工作；每种植被类型最多设置4个2米×2米的样方（quadrat）并完成拍摄与调查，此外还对圆形样地的中心区域进行了额外调查。 每个样方最多拍摄4张横向构图的照片。 总计对58个森林样地内的328个样方或样地中心区域完成了拍摄工作。 所有数据均由德国亥姆霍兹极地与海洋研究中心阿尔弗雷德·魏格纳研究所（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。