Arctic soil water chemistry in dry and wet tundra subject to snow addition, summer warming and herbivory simulation

Publication date: Available online 19 November 2019Source: Soil Biology and BiochemistryAuthor(s): Laura H. Rasmussen, Anders Michelsen, Pernille Ladegaard-Pedersen, Cecilie S. Nielsen, Bo ElberlingAbstractMultiple and rapid environmental changes in the Arctic have major consequences for the entire ecosystem. Soil water chemistry is one component with important implications for understanding climate feedbacks, plant growth, microbial turnover and net greenhouse gas emissions. Here we assess the contrasting growing season soil water chemistry in a Low arctic Greenlandic mesic tundra heath and a fen, which have been subjected to factorial treatments of summer warming using open top chambers (OTCs), snow addition using snow fences, which increase soil temperature in late winter, and shrub removal mimicking herbivory attack. Dissolved Organic Carbon (DOC) and plant nutrients, including NO3−, NH4+, PO42+ and total dissolved N were measured during multiple growing seasons (2013–2016) to quantify the treatment effects on nutrient availability at two dominating, but contrasting, vegetation types.Ambient nutrient concentrations at the mesic tundra heath decreased throughout the growing season and increased during senescence, while concentrations were highest during peak growing season in the fen. The content of NH4+ and DOC were highest in the fen, whereas NO3− was highest in the mesic tundra heath. The fen had no seasonal pattern.Summer warming in the mesic tundra heath did not...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research