Abstract
Peat bogs are important ecosystems in relation to climatic change. By forming peat, bogs serve as significant long-term sinks for atmospheric carbon dioxide. Climatic change could bring about changes in the biodiversity and species composition of these ecosystems that could have important repercussions for global carbon cycling. Experiments that have been carried out so far were too short to study the response of these ecosystems to global change. Virtually nothing is known about how climate change and changes in atmospheric N deposition would affect bog ecosystems at longer time scales. On the other hand bogs provide some unique opportunities to analyse changes in species composition during longer time periods, since the peat forms a natural archive of the history of the vegetation and carbon sequestration. Based on the sequence of plant remains (macrofossils) and precise 14C-datings in peat cores, a reconstruction of the historic plant species composition of the bog vegetation can be made. We propose to study the effects of changes in temperature, precipitation and N deposition on species composition and carbon sequestration in bogs by combining an analysis of peat cores along a North-South transect in Western Europe with a study using transplantations of peat monoliths (including the living vegetation) and experiments under controlled conditions. More specifically we will attempt:· to reconstruct the historic changes in Sphagnum and vascular plant species composition and carbon sequestration in bogs;· to determine the long-term effects of changes in temperature, precipitation, N deposition and fluctuating solar activity on species composition and carbon accumulation;· to analyse the relation between the morphological characteristics of Sphagnum species and their success at different climatic conditions; · to analyse the relation between species composition and carbon sequestration;· to investigate the long-term effects of climate change on plant species composition and carbon sequestration in bogs using a simulation model.
Netherlands