Energy balance dynamics in two stands of a Siberian larch forest located in the continuous permafrost zone near the Northeastern Science Station. Data are related to measures of radiative forcing, above- and below-ground micro-meteorological variables, ground heat flux, and sap flow measurements of tree transpiration. The dominant and only tree species is Larix cajanderi. The stands represent a high and low density forest and are located in the same fire scar and burned approximately 75 years ago. Mean tree age is 48 years old in both stands. Additional data includes root density measurements across two years, permafrost thaw depth, and soil characteristics. Tree allometry data is also included to facilitate scaling of sap flux measurements. The data is collected in association with the ViPER (Vegetation Impacts on Permafrost) project. The objective of this project is to examine the impacts of vegetation and ecosystem properties on active layer and permafrost thermal dynamics in order to better understand the vulnerability of permafrost to climate change.