Group Summary Report: Wetlands

Abstract

Wetlands include ecosystems on predominantly inorganic sediments and those that accumulate organic peat. Peat-accumulating ecosystems cover about 460 Mha — approximately 3% of the Earth’s land surface — and contain about 150 Gt of carbon — a value that may be compared with an estimate of 560 Gt of carbon in the Earth’s non-marine biomass. On the whole, these ecosystems are not of great economic importance, although they are locally exploited for agriculture (drained fens, cranberry bogs), forestry, and mining of peat. They do, however, have substantial effects on the chemistry of the water that runs from them to streams and lakes. Damage to peat-forming ecosystems is likely to be quickly reflected in water quality and possibly in the ability to act as absorbents of aerial pollutants. In spite of the actual and potential importance of peat-accumulating ecosystems, the money spent on assessing the consequences of damaging them by aerial pollution is probably less than 1% of that spent for a similar purpose on forests or on agriculture. This is short-sighted.