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No. 87: Effects of large herbivores on biodiversity of vegetation and soil microarthropods in low Arctic Greenland - Akia, West Greenland and Southern Greenland

Aastrup, P., Raundrup, K., Feilberg, J., Krogh, P.H., Schmidt, N.M. & Nabe-Nielsen, J. 2014. Effects of large herbivores on biodiversity of vegetation and soil microarthropods in low Arctic Greenland - Akia, West Greenland and Southern Greenland. Aarhus University, DCE – Danish Centre for Environment and Energy, 40 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 87 http://dce2.au.dk/pub/SR87.pdf 

Summary

This report summarizes the results of a project that aims at documenting long term effects of grazing by comparing baseline data inside and outside exclosures. We collected data on vascular plants, mosses, lichens, microarthropod abundance and food-web structure, soil nutrients, decomposition, and soil temperature. Data provide a significant basis for understanding the interaction between large herbivores and vegetation in Greenland.

The report contains documentation of data collected in 2009 and 2012 as well as documentation of data from 1984-2004 made available by Jon Feilberg.

The study took place in South Greenland, and in Akia north of Nuuk in West Greenland.  The southern Greenland localities are grazed by domestic sheep (Ovis aries), whereas Akia is grazed by caribou (Rangifer tarandus groenlandicus).

Generally there was a high similarity in plant species composition in grazed and un-grazed plots – even after more than 25 years. Few species only appearing inside or outside the exclosures, might indicate that grazing could have effects on the species composition. The cover of shrubs, herbs, and litter appeared to be favoured by not being grazed.

The nutrient content in soil was similar in grazed and un-grazed plots and generally, soil nutrients were at the same level in Akia and Kiattuut.

Generally temperatures were highest outside the exclosures and the cold season with temperatures below 0°C was longer in Akia than in Kiattuut.

The rate of decomposition was much higher in south Greenland than in West Greenland. The differences in decomposition rate between grazed and un-grazed plots were not significant in both Akia and Kiattuut.

The average diversity of microarthropods was highest in plots not being grazed.

Our dataset offers unique possibilities for analysing the relations between grazing, climate change and biodiversity in the low Arctic. Further in-depth analysis of the data collected will shed more light on the future effects of the large herbivores in the Arctic.