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.