Snow Cover

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Every ten days the staff of the reserve make an observation of the main seasonal phenomena, then to write them down in the annual Nature Chronicle. Today in the website’s special we publish the notes about the snow cover by the researcher and intern at the Research Department, Galina Veniaminovna Sokolova. The notes are based on above-mentioned observation.

 

At the Prioksko-Terrasny Reserve, the snow lies for more than four months in a year, and this fact leaves an important mark on the life of local flora and fauna. To answer the question why the snow cover is so important for nature, it is important to say first that it serves as a kind of a blanket for the earth’s surface. The air that gets inside the tiniest gaps between snowflakes rapidly reduces thermal conductivity, thus managing the freezing of soil and bogs. In spring the snow melts and enriches the soil with water, so much needed for plants.

A great number of plants and animals hibernate under the snow «blanket». For this, they develop special tools. A lot of  herbaceous and aquatic plants, such as water lilies or white water lilies, save their underground stems – root stalks, bulbs and knots. Some perennial herbaceous plants also make their leaves hibernate in a form of rosettes pushed to the ground. Such a way of hibernation can be also observed with the dandelion, barbarea, pulmonaria, common lady’s mantle and other plants of our latitude.

The snow cover also helps myomorphic rodents, which in their turn lead an active life under the snow moving around in tunnels. It is easy to spot the system of such tunnels in the spring when the upper layer of snow becomes crumbly and transparent. Under the snow, the rodents can enjoy the unfinished seeds and other «leftovers»  left by crossbills and woodpeckers. To the fortune of rodents, crossbills often leave seeds in the cones the drop down, the number of which can be up to 150 seeds. These “supplies” help the little animals to survive the winter.

An abundant snow cover sometimes can cause difficulties. For example, it creates obstacles for deer, roes and other when they need to move or find food. But the real catastrophe for the animals is the snow or ice crust. It cannot endure the weight of ungulates, especially on the run. The animals fall down deep in the snow and hurt legs, which makes them spend more time in the winter to find feed. Roes suffer from the ice crust the most, they often cannot recover from the wounds and die.

The accumulation and melting of snow cover in the Moscow region vary in different years. The years of observation in the reserve predict the average time of snow melting as April 11. The earliest date was March 24 and the latest was April 29. Such a fluctuation is also true for the snow accumulation. The average date is November 24, the earliest is October 25 and the latest is January 20. The data for observation until 2014 is provided by the station of background monitoring in the reserve.