Projectdetails

Especially in the higher latitudes temperature has risen markedly, because of global change and it is assumed that this trend will continue in the coming decades. This change in temperature is causing a change in moisture availability in the polar regions as well. Temperature and moisture availability play an important role in the functioning of terrestrial ecosystems in the polar regions. However, a proper understanding of the effects of the changes in temperature and moisture availability on the functioning of the terrestrial ecosystems in both polar regions is lacking at present. Because the changes in ecosystems structure and functioning are slow in the natural situation, an experimental approach has been developed, using Open-Top Chambers, which increase the temperature and moisture availability. These experiments are performed by various research groups in both the Arctic and the Antarctic. It is the aim of the endorsed IPY project TARANTELLA to compare the effects of experimentally induced climate change and enhanced UV-B radiation on the structure and processes of the various components of Antarctic and Arctic terrestrial ecosystems to determine similarities and differences in response between the Arctic and the Antarctic biome.

NIOO and VUA have been using Open-Top Chambers in both Arctic and Antarctic terrestrial ecosystems. The aim of the present proposal is to focus on a number of novel studies in both polar regions, using the already existing infrastructure. The Dutch involvement in the TARANTELLA project comprises three projects:

In project I we will focus on temperature-induced changes in water availability and water sequestration, using experimental studies with deuterium-labeled water in combination with studies of the natural abundances of deuterium in several water sources (rain, snow, soil water) to track possible changes in the type of water sequestration. This will be the first field study in which this integrated approach will be used to study the effects of climate change on water use of vascular plant species.

In project II we correlatively and experimentally study the transfer of 18O and 2H from rainwater and spring melt water to segments of the tundra plants. The Annual Growth Increment of and values of 18O and 2H therein represents a new climate proxy by which past temperature and variation of the Arctic oscillation is reconstructed.

In project III we will study the effects temperature change and changes in water availability on carbon and nitrogen fluxes, focusing on the rates of decomposition and on the role of the invertebrate community in the decomposition process. This proposal is the first in Antarctica to study the consequences of warming on the role of invertebrates in the decomposition process while no overall comparison has previously been attempted between Arctic and Antarctic situations.