Plant species composition and aboveground biomass data for Saddle snowfence, 1996 - ongoing.

Bowman et al. (1993) have demonstrated that alpine tundra is sensitive to nitrogen and phosphorus additions. Changes in productivity and species composition (belatedly) follow chronic fertilization. Exactly how this response is mediated by changes in precipitation is unknown but can be addressed using the snowfence experiment. Moreover, replication of the experiment will allow for additional sampling of biotic and abiotic components and processes not possible with the size of the Bowman plots. In 1993, 64 2x2m plots were placed in dry and mesic sites both within and outside of the snowfence area, so that 4 replicates of each treatment (nitrogen addition, phosphorus addition, nitrogen and phosphorus addition, and control) could be established in each meadow type with and without snowpack augmentation. 16 additional plots were established on a wet meadow site, but since a corresponding type site did not exist in the snowfence area, there was no snowpack manipulation for the wet meadow plots. In 2016, 9 existing plots were selected and 6 control plots added for assessing recovery from augmented snowpack treatment. Aboveground biomass, species richness, and species composition have been collected periodically since 1996.