Does forest stand structure impact the dynamics of snow on winter grazing grounds of reindeer (Rangifer t. tarandus)?

The landscape in boreal Sweden is dominated by even-aged, single-layered forest monocultures and clear cuts. Few forest stands with a more complex, multi-layered structure remain as landscape elements. We studied the impact that different forest management regimes have on snow conditions and the metamorphosis of snow, and discuss how these factors may affect suitability for reindeer grazing.Over two winters, we recorded the development of snow depth and hardness in clear cuts and two different forest types, and their changes with weather events. In the forests, the dynamics of snow characteristics were analyzed in relation to stand structure and at the level of individual trees.There were no clear differences in snow characteristics between single-layered and multi-layered stands, although snow hardness was more variable in the latter. In single-layered stands, snow depth and hardness were spatially uniformly distributed in relation to stand characteristics. Contrastingly, the complex structure of multi-layered stands did influence snow depth significantly. However, hardness was highly heterogeneous in these stands. Due to the absence of tree effects, clear cuts had deeper but softer snow than forested stands, although hardness increased towards spring.Weather affected the metamorphosis of the snow blanket. The magnitude of the effects depended on both timing and severity of discrete weather events and forest structure, but generally weather had a greater influence on snow cover characteristics than forest structure per se. In their interaction with weather, different forest structures affect the snow and thus suitability as winter grazing area for reindeer. Reindeer herders, therefore, require diversity in the landscape in order to respond to such weather variations and their impact on grazing conditions.