Beavers, the masters of retention in the Białowieża Forest

Once again, a small animal proves it can outshine even experienced hydrotechnicians. A project conducted by researchers from the Polish Academy of Sciences shows that beavers in the Białowieża Forest store nearly 1 million m³ of water in their ingenious ecological infrastructure. In a time of intensifying hydrological drought, this fact certainly deserves recognition!

Counted and measured – the results are surprising

Dr. Tom Diserens from the Mammal Research Institute of the Polish Academy of Sciences in Białowieża is leading a three-year project entitled How do wolves and humans shape the spatial use and environmental impact of the beaver? As part of fieldwork, his team covered many kilometers of the Białowieża Forest in search of signs of beaver activity. The results were impressive.

In the Polish part of the forest, researchers found 140 active beaver sites and 20 abandoned ones – with a total estimated at around 200. Between them, thousands of channels, burrows, and lodges were discovered, clearly indicating who the forest’s hardest-working resident is.

To estimate the impact of beaver activity on water retention in the Białowieża Forest, Dr. Diserens assumed that one dam retains about 3,000 m³ of surface water and an additional 1,250 m³ of groundwater (due to raised water levels). These are very conservative estimates, so the actual efficiency of beaver families may be even higher.

After summing up the numbers, it turned out that beavers in the Białowieża Forest store as much as 850,000 m³ of water in natural reservoirs. This is an extraordinary potential in the face of increasingly dry winters and springs. According to representatives of the Regional Directorate for Environmental Protection in Białystok, some of these reservoirs were dry at the beginning of summer, but recent rainfall helped refill them, creating a valuable water reserve for the forest ecosystem.

The forest lives thanks to water

Just a week ago, many of the beaver ponds in the Białowieża Forest were empty. Tom Diserens noted on his Facebook profile that the entrances to the lodges, which are normally underwater, were dangerously exposed. For beavers, diving into the water is the only way to escape predators.

“Beavers can’t survive long in an environment without water. They have to move to better habitats or risk being eaten by wolves,” adds the scientist. In his view, the current water crisis in Poland threatens both forests and beavers. During this year’s drought, it became clearly visible that the animals began to retreat from smaller streams and wetlands.

Beavers in the Białowieża Forest keep things in order

The current beaver population in the Białowieża Forest is around 40 families – revealed Tom Diserens in an interview with PAP. This is a major ecological success, as in the 1980s they were practically nonexistent here. Each family consists of two parents and several young – both from the current and previous year. All members work hard to maintain the lodges and dams, which play such a crucial role in the forest’s life.

Retention is not the only positive effect of the beavers’ presence in the Białowieża Forest. According to Dr. Diserens, just a few decades ago, riverbeds were completely covered by large trees, making them invisible in satellite images. The activity of these small engineers has opened up the landscape and increased light access, benefiting many plant species.

These facts are an important voice in the discussion about the future of beavers in Poland – praised by ecologists on the one hand, criticized by farmers on the other. Can the culling of animals that may be the saviors of our drying forests truly be justified in a rational way?