Prediction of change in wetland habitats by groundwater: case study in Northeast Lithuania

Abstract

The main aim of this article is to assess changes in important waterfowl habitats – protected wetlands situated in the impact zone of proposed dolomite mining. The changes in the waterfowl habitats are evaluated according to changes in the area of sub-wetlands that compose the principal basis of the waterfowl habitat. The sub-wetlands were selected according to vegetation structure of Lake Čedasas and its riparian zone (northern Lithuania). The open water, hydrophyte, helophyte, open grass and mire scrub sub-wetlands were distinguished. According to the simulation results, the decrease in groundwater level between 6 and 7 m in the dolomite quarry would not produce a decline of the water level of Lake Čedasas and groundwater level in the riparian zone, but the lowering of the ground­water level in the dolomite quarry and predicted climate change will produce a decline of groundwater level of as much as 10 cm in the surroundings of the investigated lake. The water level of Lake Čedasas would also decrease by about 10 cm. Even these minor water level changes will influence the ecosystems of Lake Čedasas. The following changes are predicted: open water territory will diminish by about 25%, the area covered by hydrophytes will increase by about 15% and the area covered by helophytes will decrease by about 17%, the area of the open grass sub-wetland will decline by about 5%, whereas the area of the mire scrub sub-wetland will increase even by as much as 28%. The research results showed that the selected mathematical model could be employed to produce a useful simulation of surface water resources and understand the wetland habitats response to disturbances in the water regime