Cajander larch fine root, soil organic layer, and active layer depths across a tree density gradient in northeastern Siberia. 2017.

Greater tree density and forest productivity at the tundra-taiga ecotone (TTE) are expected with climate warming, with potential feedbacks to the climate system. Yet, competition for nitrogen (N) may impact TTE dynamics. Greater tree density will likely increase N demand, while reducing N supply through soil shading and slower decomposition rates. We explored whether root characteristics important to N acquisition and soil characteristics indicative of soil N availability responded to changes in density at the TTE. In this dataset, we characterized the depth of fine roots of Cajander larch (Larix cajanderi), the soil organic layer, and the active layer in 10 stands arrayed across a tree density gradient at the taiga-tundra ecotone in far northeastern Siberia in September, 2017.