Circular Survey of Forest and Shrub Layer Vegetation Cover in Northwestern Canadian Boreal Forests in Summer 2022

Vegetation surveys were carried out in Northwest Territories, Yukon and British Columbia in Canada. The study area is within the boreal forest biome and is partially underlain by permafrost soils. The aim was to record the projective ground vegetation in different boreal forest types studied during the CA-Land_2022_NWCanada field campaign in July and August 2022. Projective cover of tall shrubs and trees was estimated on 15-m radius circular plots directly, with "tall" referring to plants which are mainly >40 cm in height and do not belong to the group of typical ground-cover plants like grasses or dwarf shrubs. Vegetation cover was assessed using a modified Braun–Blanquet approach. The categories r and + were converted to 0.05% and 0.1% cover, respectively, whereas cover values of 0.5–100% were recorded directly as estimated percentages rather than as categorical Braun–Blanquet score. In total 32 forest plots were investigated. All data were collected by scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) Germany, and the University of Potsdam Germany.