CENPERM project
Investigating soil dynamics in a permafrost environment under climate change.
Center for Permafrost (http://cenperm.ku.dk) was started in 2012 as a Center of Excellence. The long-term research initiative is a collaboration based at the University of Copenhagen, with several national and international collaborators such as the Geological Survey of Denmark (GEUS), University of Aarhus, the Danish Meteorological Institute, including other permafrost research initiatives such as the International Network for Terrestrial Research and Monitoring in the Arctic (INTERACT), DEFROST and PAGE21. The research strategy combines ecosystem investigations on climate responses, physical landscape dynamics, terrestrial ecology and soil science, in field sites in Greenland, Svalbard, Sweden and Canada.
CENPERM has among other things established two large-scale snow fence field experiments in a dry shrub heath and a wetland area at Disko Island, West Greenland. These experiments are designed to study the impact of summer and winter warming on the ecosystem functioning of Arctic tundra vegetation, microbes, soil animals and permafrost. We study interacting processes between microorganisms, plants, soil animals and soils in soil profiles at contrasting landscape and vegetation types. We integrate depth-specific processes and study the net effects on a plot scale. The field experiments involve snow accumulation (=higher winter temperature), warming chambers (=higher summer temperature) and shrub removal (=lower summer temperature) in a full-factorial experimental design. We also include the use of existing long-term ecosystem field manipulations of soil temperature, solar radiation, snow depth and water availability at Zackenberg, northeast Greenland, and Nuuk, western Greenland. We do this in order to understand key processes controlling permafrost formation and decay.
Zackenberg project
Effects of climate change on soil microarthropod diversity and ecological function.
The aim of this study is to investigate long-term environmental change responses of soil microarthropods and the impact on their community structure, in Zackenberg, Greenland. The project is in collaboration with the University of Copenhagen, and Zackenberg Ecological Research Operations (http://www.zackenberg.dk). In 1996, an experiment with water application to the soil weekly during the growing season, as well as two years of N or P addition, was established in a semi desert on a dry gravel terrace adjacent to the river delta banks of the Zackenberg River. Another experiment was started in 2004 in a Cassiope tetragona and a Salix arctica heath with treatments of warming (plastic greenhouses), increased cloud cover (shading nets) and changed growing season length (snow cover removal or addition). Plants and soil are sampled from these three experiment sites for soil fauna identification and counting, and for measurements of nutrient content and microbial biomass.
Abisko project
Linking microarthropod contribution to N turnover to overall ecosystem function
The project aims to investigate soil biodiversity, microarthropod species and population densities, life cycles, population dynamics and turnover, to understand the effects of climate change on the decomposition processes. Experimental sites for investigation of effects of environmental changes on biological and physiological processes were set up in 2007 close to Abisko, northern Swedish Lapland (68°21’N, 18°40’E). Climate records (1989–2002) from the nearby Abisko Scientific Research Station at 385 m elevation showed an annual mean temperature of 1.7 °C at 5 cm soil depth, with minimum and maximum temperatures of -9.3 and 12.5 °C, respectively. The field is an open, hydric glade in a birch forest at 385 m elevation. Plant cover consists mainly of dwarf shrubs, graminoids and mosses, in a wet, peaty environment. The experiments consisted of manipulations of temperature and fertilisation, as well as marking with labelled 15N. The stable isotope 15N is used as a marker for multi-annual and seasonal changes of distribution and transfers of N in the plant-microbe-soil systems and interfaces. The project investigates the changes of distribution of N in the ecosystem pools, and transfer of N from the microarthropods. The distribution and transportation of N in the soil system has already been investigated for several of the different plant and soil parameters at this site, which make the inclusion of new results regarding soil microarthropods possible.