Effect of altered snow conditions on decomposition in three subalpine plant communities

Abstract

Snow cover and its spatio-temporal changes play a crucial role in the ecological functioning of mountains. Some human activities affecting snow properties may cause shifts in the biotic components of ecosystems, including decomposition. However, these activities remain poorly understood in subalpine environments. We explored the effect of human-modified snow conditions on cellulose decomposition in three vegetation types. Snow density, soil temperature, and the decomposition of cellulose were studied in Athyrium, Calamagrostis, and Vaccinium vegetation types, comparing stands intersected by groomed ski slope and natural (outside the ski slope) stands. Increased snow density caused the deterioration of snow insulation and decreased the soil temperature inside the ski slope only slightly in comparison with that outside the ski slope in all vegetation types studied. The decomposition was apparently lower in Athyrium vegetation relative to the other vegetation types and strongly (Athyrium vegetation) to weakly lower (other vegetation types) in groomed than in ungroomed stands. Wintertime, including the melting period, was decisive for overall decomposition. Our results suggest that differences in decomposition are influenced by ski slope operations and vegetation type. Alterations in snow conditions appeared to be subtle and long-term but with important consequences for conservation management.

How alpine heathlands response to the snow cover change on the ski slope? Long-lasting ski slope impact case study from the Hrubý Jeseník Mts (Central Europe)

“…This result is in line with other studies from various alpine sites [7,9] and with studies from other vegetation types at the study area [17,22,23]. The changes in the snow quality were mirrored by SWE that increased during winter both inside and outside the ski slope, but were even faster inside the slope due to snow fences functioning.…”

“…Similar values were found under groomed snow at alpine grasslands in the Alps [31] and the inside stands of some other vegetation types at the ski slope in the Hrubý Jeseník Mts [17,23]. Despite higher snow compaction, the relatively slight temperature drops inside the ski slope are a consequence of the increased thickness of the snow cover inside ski slope due to snow interception by snow fences installed along studied ski slope [17,23]. The same effect can be achieved by huge amounts of artificial snow that counteract the reduced insulating properties of the snowpack in some parts of the Alps [12].…”

“…Our observations confirmed lower average daily temperatures of approximately 0.3°C in bilberry stands inside compared to outside the ski slope. Similar values were found under groomed snow at alpine grasslands in the Alps [31] and the inside stands of some other vegetation types at the ski slope in the Hrubý Jeseník Mts [17,23]. Despite higher snow compaction, the relatively slight temperature drops inside the ski slope are a consequence of the increased thickness of the snow cover inside ski slope due to snow interception by snow fences installed along studied ski slope [17,23].…”

“…The study was performed at the NW slope of Petrovy kameny Mt (1448 m a.s.l., 50°04' N, 17°14' E, mean inclination 24°) in the alpine belt above timberline [20]. The composition of the alpine vegetation, soil, and several other abiotic and biotic conditions, including the geomorphology of the site, are described in detail by Křížek et al [21], Treml and Banaš [20], Zeidler et al [22], Banaš et al [17], Hédl et al [14], and Zeidler et al [23]. One part of the slope is established as the investigated ski slope and an adjacent one left as a natural area under protection.…”

“…Essential differences in the temperature course between the ski slope and natural plots appeared during the spring and snowmelting period. Because the prepared compacted snow cover remains longer than the natural snow [7,9,23,31], the soil warming and beginning of the snow-free season inside ski slope under consideration is delayed approximately 3 weeks compared with the outside, which is the prevalent interval at ski slopes in general [7,12,17]. Consequently, the ground soil of the ski slope receives less solar radiation in spring when it is still covered with snow, while the outside areas are already snow free.…”