One of the phenomena of the park is the high extent of its degree of purification which in average exceeds 40%. Mires make an integral part of the park's landscapes. Abundant dampings, flat-country relief, surface deposition of waterproof rocks have called forth such a high extent of paludification.
Types of mires. According to regimen of water- mineral nutrition and cover mires of the park are divided into 10 types. High peat moss hummock-ridge bogs and transitory hummock-ridge aapa bogs predominate. Rare and unique are lowland grass- moss bogs where grow numerous species of grasses, sphagnous and green mosses.