Effects of disturbance on plant regrowth along snow pack gradients in alpine habitats

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.