Changes in the field-layer of Wytham Woods - assessment of the impacts of a range of environmental factors controlling change.

Uppsala

2008

S. 307-320

8 Abb., 1 Tab., zahlr. Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200150149

What are the long-term effects of climate change on the plant species composition and carbon sequestration in peat bogs? We developed a bog ecosystem model that includes vegetation, carbon, nitrogen and water dynamics. Two groups of vascular plant species and three groups of Sphagnum species compete with each other for light and nitrogen. The model was tested by comparing the outcome with long-term historic vegetation changes in peat cores from Denmark and England. A climate scenario was used to analyse the future effects of atmospheric CO2, temperature and precipitation. The main changes in the species composition since 1766 were simulated by the model. Simulations for a future warmer, and slightly wetter, climate with doubling CO2 concentration suggest that little will change in species composition, due to the contrasting effects of increasing temperatures (favouring vascular plants) and CO2 (favouring Sphagnum). Further analysis of the effects of temperature showed that simulated carbon sequestration is negatively related to vascular plant expansion. Model results show that increasing temperatures may still increase carbon accumulation at cool, low N deposition sites, but decrease carbon accumulation at high N deposition sites.