Strzalowo is a Polish demo area with the aim to show beaver management.
Strzałowo upstream dam 53.688N, 21.3557E
Strzałowo middle dam 53.6892N, 21.3691E
Strzałowo downstream dam 53.6884N, 21.3785E
Mean annual temperature: 7,6°C (1981-2010)
Growing season days: 180-190 days
Annual precipitation: 590 millimetres
Middle boreal forest vegetation zone: forest of temperate zone
Demo area Strzałowo 1 is located on the Nawiadka River, which connects two lakes. The length of the river is 2480 meters, and the difference in the water level between the lakes is 5,05 meters. At the turn of the 19th and 20th centuries the river was regulated at a length of about 2000 meters.
In 2007, in the frame of the project "Recreation of wetland ecosystems in the area of the Forest District of Strzałowo", a few hydraulic structures were built on the river. After their execution, beavers lived on the river by building three dams. Forest occupies about 70 percent of the area on this site.
The remaining 30 percent is occupied by meadows, arable lands, water reservoirs, pastures and recreational facilities. The occurring forest habitat types are:
- fresh forest (3,9 percent),
- mixed fresh forest (89 percent) and
- riparian forest (7,1 percent).
Tree species that dominate the area are: Scots pine and black alder. Both species come from plantings, and only to a small extent from natural regeneration. There are five classes of stand age. The most numerous is the third class (41-60 years), which covers almost 60 percent of the area. Another class-significant class is class IV (61-80 years), which covers almost 30 percent of the area. Historically, the area currently covered with forest was used as arable land, meadows and pastures.
Conducted work and time plan for future activities
In order to assess the impact of beavers there are collected three times a year of water samples from seven points marked in the below scheme. In addition, various organisms (biota) are taken by the team from the University of Uppsala to determine the content of mercury and methyl mercury in them. At the beginning of 2018, the middle tame was removed for experimental purposes. In the future, observations are planned regarding changes in the settlement of beavers on the river and control tests of water quality.