Siemianówka - Impact of the water reservoir on forest communities

The original assumption of the project was to assess the rate of disturbances in the structure and dynamics of forest communities under the influence of the Narew – Siemianówka water reservoir. The reservoir was established in 1977 and its filling was completed in 1990. The maximum area of the reservoir counts 32 km2 and its capacity is about 80 million m3 of water. Prof. Faliński assumed that the constant accumulation of water in the basin under different environmental conditions may result in at least three types of hydrological changes, leading to far-reaching changes in the forests in the vicinity. Possible changes include: halting of flowing water, activation of still water and permanent raising or lowering of the groundwater table.

The research is conducted in the Siemianówka Reserve (225 ha), established on the initiative of prof. Janusz B. Faliński in 1995, especially for monitoring changes taking place in marshy forest communities: alder carr and boreal spruce forests. Eleven permanent plots were established in the reserve, with additional 7 plots in its vicinity, each of 400 m2. Plant species survey with estimation of the coverage of each species are conducted every two years within each plot.