DOI: 10.5061/dryad.0k6djhb2j
title: Effects of disturbance on plant regrowth along snow pack gradients in alpine habitats

description: Human disturbance in alpine habitats is expected to increase, and improved
 knowledge of short-term recovery  after disturbance events is
 necessary to interpret vegetation responses and formulate planning and
 mitigation efforts. The ability of a plant community to return to its
 original state after a disturbance (community resilience) depends on
 species composition and environmental conditions. The aim of this study is
 to analyze initial short-term effects of disturbance in alpine plant
 communities in contrasting climates (oceanic vs. continental; central
 Norway). We used a nested block-design to examine vegetative regrowth and
 seedling recruitment after experimental perturbation. Three plant
 community types along the snow pack gradient were exposed to (1) no
 disturbance, (2) clipping, and (3) clipping and uprooting. Slow vegetative
 regrowth and low seedling establishment rates were found in dry alpine
 ridges and late-melting oceanic snowbed communities. Leeside habitats with
 intermediate snow conditions were found more resilient. The difference was
 related to growth form and species diversity. Woody species, which
 dominated in ridges and oceanic snowbeds, showed the most negative
 response to disturbance. Species-rich plant communities dominated by
 graminoids and herbs showed higher rates of regrowth. Species richness
 seems to cause resilience to the plant communities through higher response
 diversity. Plant communities at the extreme ends of abiotic gradients,
 ridges and late-melting snowbeds, will be most sensitive to both
 disturbance and environmental change. In an up-scaled human-used landscape
 disturbance effects will be amplified and further limit recovery to a
 pre-disturbance state.
description: The data consists of floristic composition in
 216 plots pre-disturbance and after disturbance, in three habitat types in
 two alpine sites. The experiment was performed using a nested design. In
 each site (1 km<sup>2</sup>), three transects were selected
 subjectively. All transects included three vegetation communities
 (habitats) along the snow pack gradient; ridge, leeside, and snowbed.
 Within the habitat, 12 permanent plots (0.5 x 0.5
 m<sup>2</sup>) were randomly located, giving totally 36 plots
 per transect and 108 plots per site. The distance between plots was
 minimum 2 m. Within each habitat, plots were randomly allocated to one of
 three disturbance types: no disturbance (control), moderate disturbance
 (clipping and removing of field layer vegetation; simulating summer
 grazing by sheep and reindeer), or severe disturbance (removing of field
 layer and bottom layer vegetation, and roots that could be removed/pulled
 without digging; simulating anthropogenic disturbance such as trampling
 and motorized summer activities). Prior to
 disturbance treatments (late 2007/early 2008), total vegetation cover and
 bare soil was recorded as % cover. Abundance of vascular plants was
 recorded as the presence/absence of each species in 16 subplots (12.5 x
 12.5 cm<sup>2</sup>) per plot. Plots were reanalyzed at the
 end of the growing season in 2009. Additionally, a detailed post-growing
 season search for seedlings was performed in all plots in
 2009.