Abstract Forested wetlands are one of the most sensitive ecosystem types in regard to shifts in climatic regimes. It is commonly acknowledged that hydroperiod is the dominant influence on all ecological processes in wetlands. Wetland dynamics are a function of the balance between inflows and outflows of water.
Flooding changes the physical, chemical and microbiological properties of a soil.
It leads to the differentiation between macro and microenvironments in redox state, physical properties and chemistry which causes major changes in soil chemical and microbial function. One of the earliest plant responses to flooding is stomatal closure. However, the rate of closure, degree of closure, and recovery of stomates varies with species. Therefore, even small differences in flooding frequency and duration can cause major differences in plant species composition. Hydroperiod may be one of the wetland characteristics that is most sensitive to anthropogenic impacts.