Snowbed communities and soil C and N dynamics during a four-year investigation in the NW-Italian Alps

The snowbed habitats represent a relevant component of the alpine tundra biome, developing in areas characterized by long-lasting snow cover. Such are particularly sensitive to climate changes, because small variations air temperature, rain, and snowfall may considerably affect pedoclimate plant phenology, which control soil C N cycling. Therefore, it is fundamental identify most abiotic biotic variables affecting nutrient This work was performed at seven permanent sites belonging Salicetum herbaceae vegetation community northwestern Italian Alps, elevations between 2,686 2,840 m.a.s.l. During four-year study, we investigated climate, pedoclimate, floristic composition, dynamics. We found that lower water content earlier melt-out day decreased N-NH4+, N-NO3−, dissolved organic carbon (DOC), nitrogen (DON), total (TDN), microbial (Nmicr), (Cmicr), C:Nmicr ratio. progression phenological stages Salix herbacea reduced N-NH4+ increased DOC. Our results showed day, content, were important factors biogeochemical cycles, they should be taken into account when assessing effects change ecosystems, framework long-term ecological research.