Trophic specialisation levels of geese, lemmings and ruminants with regard to transformation of Arctic herbivore communities
I. S. Sheremetev
Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS, Russian Academy of Sciences, Vladivostok, Russia
Keywords: Arctic, geese, global change, lemmings, ruminants, selectivity, specialization
Abstract
Despite more and more data on the Arctic biotic communities even the principal course of their transformation remains unclear. In this concern the profound interest is related to differences in population dynamics of geese, lemmings and ruminants covering more than 98 percent of the Arctic terrestrial ecosystem recycling and competing on the specialization ground for the same food resources. Comparing 15 species of the taxa we showed that grades of their morphophysiological adaptation to phytophagy are matched to empirical estimates of their food selectivity, thereby describing their trophic specialization distribution. Thus in the Arctic herbivore communities the selectivity distribution is so stable as specialization. The trophic specialists include muskox and snow goose in the first place, while the generalists are lemmings and smallest black geese. The specialist populations have mainly higher size and/or growth rate than the generalist populations have. It may be concluded that interspecific competition influence contemporary transformation of the Arctic herbivore communities much stronger than such environmental factor as global warming and human activity do.
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