Rangelands in a changing climate: Impacts, Adaptations, and Mitigation
- F. S. Chapin, S. Diaz, M. Howden, J. Fuigdefábregas, M. Stafford Smith.
- Pages 134-158 in Watson et al., eds. Climate…
Global climate change, induced by increase in the concentration of greenhouse gases in the atmosphere, can affect the growth and community structure of grassland ecosystems in two ways. The first is directly through changes in atmospheric concentration of CO 2 and the second is indirectly through changes in temperature and rainfall. At higher latitudes, where growth is largely temperature limited, it is probable that the direct effects of enhanced CO2 will be less than at low latitudes. However, interactions with increasing temperature and water stress are complex. Grasslands range from intensively managed monocultures of sown species to species-rich natural and semi-natural communities whose regional distributions are controlled by variations in soil type and seasonal patterns of temperature and rainfall. The different species can show marked differences in their responses to increasing CO 2 concentrations, rising temperatures and water stress. This will probably result in major alterations in the community structure of grasslands in the future and possible shifts in ecosystem boundaries. In addition to impacts on primary productivity and community structure, a long-term effect of elevated CO2 on grasslands is likely to be a significant increase in soil carbon storage. However, this may be counteracted by increases in temperature.