For extensive wetlands, a change in the water
balance in favor of enhanced evaporation (due to
warmer and longer summer season than the present)
will not only lead to greater water loss from the
wetland patches themselves, but will also reduce the
water inputs from their catchments. Therefore, many
wetland patches will then be adversely affected.
Enhanced thawing of permafrost due to climatic
warming may lower the water table, which is
unfavorable to most existing wetlands, but increased
thermokarst activities can cause flooding in some
areas to create new wetlands, or to switch from bogs
to fens (Grossman and Taylor 1996; Woo and Young
2006).