Копытные млекопитающие как селективная сила по отношению к суркам (Marmota). [Ungulate animals as selective force for marmots. Ongulés comme force sélective en rapport pour les marmottes].

Résumé

UNGULATE ANIMALS AS SELECTIVE FORCE FOR MARMOTS E.A. Karpukhina, V.S. Orlova, A.A. Nikol’skii Russian Peoples’ Friendship University: nemorum@mail.ru; eagleson@mail.ru; bobak@list.ru Attachment of marmots to grazing places of ungulate animals has been discussed in literature many times (Tokarskii, 1997; Mashkin, 1997; Ronkin, Savchenko, 2000; Savchenko, 2002; Savchenko, Ronkin, 2006). We consider grazing to be a selective force, influencing the life of marmots. There are at least 6 reasons to think so: Grazing changes flora and species correlation in plant communities. New structure of flora better corresponds to food specialization of marmot. Changes in environment connected with grazing (increasing soil density, disappearance of litter layer, increasing role of xerophytes in plant communities, early beginning of vegetation, decreasing plant height) give some ad-vantages to marmots. Grazing prolongs the period of steppe plants growth and development. Young shoots contain more nutrition (proteins, etc.) Eating young parts of plants gives marmots an opportunity to create nutrition stock and use metabolic water. Grazing increases the spatial and temporal heterogeneity of steppe plant communities and steppe ecosystems. In different periods during activity season different steppe plots should be optimal for marmots. Grazing gives some plant species better possibilities to seed and/or vegetative reproduction and also fertilizes the soil. There is a possibility that marmots and ungulate animals have the same species of symbiotic microorganisms in digestive system and marmots became infected with symbionts on pasture.