Shrub expansion in Alpine Tundra of the Kluane Region

We have conducted experimental manipulations of shrub canopies in the south-western Yukon. For the 12 shrub and 12 tundra plots, we have measured soil temperatures, snow depths, soil profiles, carbon dioxide effluxes, plant available nitrate and ammonia, tundra and shrub biomass, and percent carbon and nitrogen in soils and plant biomass. We have also collected shrub growth ring data and ages for willows from 20 sites in the Kluane Region and other sites in the Yukon.