摘要：Noémie Boulanger-Lapointe ab* , Esther Lévesque ab , Claudia Baittinger c & Niels M. Schmidt dea Department of Environmental Sciences Université du Québec à Trois-Rivières, 3351 boul. des Forges, C.P. 500 , Trois-Rivières, Quebec G9A 5H7, Canada b Center for Northern Studies, Université Laval , 2405 rue de la Terrasse, Québec G1V 0A6, Canada c Environmental Archaeology and Materials Science National Museum of Denmark , Frederiksholms Kanal 12, DK-1220 Copenhagen, Denmark d Department of Bioscience Aarhus University , Frederiksborgvej 399, DK-4000 Roskilde, Denmark e Arctic Research Centre, Aarhus University , C.F. Møllers Allé 8, DK-8000 Aarhus C, Denmark Correspondence Noémie Boulanger-Lapointe, Department of Geography, University of British Columbia, 1984 West Mall, Vancouver, British Columbia V6T 1Z4, Canada. E-mail: noemie.boulanger-lapointe@geog.ubc.ca Arctic terrestrial ecosystems are heterogeneous because of the strong influences of microtopography, soil moisture and snow accumulation on vegetation distribution. The interaction between local biotic and abiotic factors and global climate patterns will influence species responses to climate change. Salix arctica (Arctic willow) is a structuring species, ubiquitous and widespread, and as such is one of the most important shrub species in the High Arctic. In this study, we measured S. arctica reproductive effort, early establishment, survival and growth in the Zackenberg valley, north-east Greenland. We sampled four plant communities that varied with respect to snow conditions, soil moisture, nutrient content and plant composition. We found large variability in reproductive effort and success with total catkin density ranging from 0.6 to 66 catkins/m2 and seedling density from <1 to 101 seedlings/m2. There were also major differences in crown area increment (4–23 cm2/year) and stem radial growth (40–74 µm/year). The snowbed community, which experienced a recent reduction in snow cover, supported young populations with high reproductive effort, establishment and growth. Soil nutrient content and herbivore activity apparently did not strongly constrain plant reproduction and growth, but competition by Cassiope tetragona and low soil moisture may inhibit performance. Our results show that local environmental factors, such as snow accumulation, have a significant impact on tundra plant response to climate change and will affect the understanding of regional vegetation response to climate change.
