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No. 2: Herbivore influences on ecosystem functioning

Schmidt, N.M., Krogh, P.H. & Forchhammer, M.C. 2011. Herbivore influences on ecosystem functioning. Establishment of musk ox exclosures at Zakenberg. Aarhus University, DCE - Danish Centre for Environment and Energy. 20 pp. - Technical Report from DCE - Danish Centre for Environment and Energy No. 2. www2.dmu.dk/Pub/TR2.pdf

Summary

In July 2010 we established permanent musk ox exclosures in the large fen area Rylekærene at Zackenberg, Northeast Greenland. The set-up consists of two treatments, exclosure (EX) and snow-control (SC), and one control (C). The EX plots inhibit musk ox grazing, while the SC plots serve as controls for the potential effects of the fence itself, whilst still allowing musk oxen to graze the plot. The C plots are unmanipulated controls. A randomized complete blocks design (RCBD) was established with three plots per each of 5 blocks, including the treatments EX, SC and C. Each plot measures 10x10m, and are positioned facing NNW, which is the dominating wind direction during winter. The EX plots are fenced on all four sides, while SC has a fence towards NNW only, thereby making the potential snowfence-effect in SC and EX plots comparable. The C plots are marked by iron posts only.

In connection with the establishment of the exclosures, a suite of baseline data were collected. These include data on plant diversity and species composition (frequency analysis), estimates of plant biomass, leaf area index and NDVI. Soil fauna species biodiversity and species composition, as well as their food web structure derived from natural abundances of 13C and 15N, were examined treatment-wise across plot replicates. In all plots we also placed soil temperature loggers to allow for detection of changes sin soil temperature, nutrient probes to examine the level of nutrients, and litter-bags to examine decomposition rates in the various treatments. Additional data collected were soil characteristics and depth of the active layer.