7. An Examination of the Use of Salix Arctica for Dendrochronological Studies in the Arctic

Abstract

Large scale land disturbances are occurring in sensitive Arctic regions as a result of climate change. These disturbances which are caused by permafrost melting and can damage fragile tundra ecosystems and have important impacts on downstream water quality. Determining the timeline of these disturbances will aid in the understanding of the effect of climate change in the Arctic. This can be performed through the analysis of environmental proxy records such as those found in the annual growth rings of trees, which express environmental stresses, such as those experienced during a land disturbance. Dendrochronology of the most northern occurring woody plant, Salix arctica (arctic willow) has been explored only a few times in the past, and its potential for paleoenvironmental studies in the Arctic have been largely over‐looked. We examined the thickness of annual growth rings from S. arctica from two areas of land disturbance on southern Melville Island, Nunavut. Common growth trends were found in both dead (snag) and living samples from the sites. Preliminary data show that a substantial disturbance in the growth of the samples is evident approximately 40 years ago and was likely due to land disturbance. These initial findings demonstrate the successful use of S. arctica as a paleoenvironmental indicator and provide useful tools to determine the timing of past permafrost disturbances and climate change in the Arctic. We are continuing to investigate additional samples from other sites to determine if the method can be used as a novel tool for understanding permafrost landscape dynamics.