Since the early 1980s, I have spent much time in Naliboki Forest. Mostly doing the study on vertebrate predators, I always snatched an opportunity to visit the remains of the primeval forest, where trees saw axe and saw rarely and where some of the trees still remembered the Middle Age time. Such pristine forest magnetized so much.
In this terrain broad-leaved deciduous forest older than 100 years (i.e. real broad-leaved deciduous oldgrowth) survived on a very small part of Naliboki Forest only – 0.3% (it is about 6 km2). Nevertheless, in Belarus and other neighbouring regions there are actually a few forest massive, where such centuries-old forest plots still exist, and, so, Naliboki Forest is one of them. In these oldgrowth patches the oldest oak trees, which grow on the distance of 15-60 meters apart, have an age of 200-400 years. In the oldest tree stands the mean oak age constituted 326 years old according to 14 estimates. Also, in the deciduous broad-leaved oldgrowth there are old maples, limes and ashes (but ashes die in numbers nowadays).
Also it worthwhile to notice that in Naliboki Forest there are some more than 30 km2 of broad-leaved deciduous forest, which is not so old of about 100 years old, but where centuries-old trees are more or less common in the tree stands.
Once in the early 2000s, I decided to get know what is the main part of the vertebrate predator-prey community in the primeval broadleaved deciduous oldgrowth of Naliboki Forest. The answer appeared quite ordinary. By doing the census of vertebrate predators and their prey as well as dietary studies of the main predators, there were found the two basic predator-prey relationships. First, lynxes consume roe deer and mountain hare that are common in the oldgrowth. Second, weasels, pine marten and tawny owls rely on yellow-necked mice and bank voles, whereas these rodents depend on acorn crop, but not strongly because of the stable presence of maple and lime seeds each autumn as well as herb food abundance.
Let’s say there were two main key species such as the yellow-necked mouse and weasel that were so plentiful in the oldgrowth. On each one km2 there were censused 7 to 31, mean about 17 weasels. Concerning yellow-necked mice, there were approximately found (by means of census and calculations) 60-200 individuals per a hectare. Interestingly, that both these predator and prey spend a lot of time in huge trunks of centuries-old trees. Concerning weasels, more than a half of radiofixes of the radiotagged weasel were registered in such a trunk having many cavities and hollows. Quite often the weasel was on a height inside the trunks.
Zoology by Vadim Sidorovich 