Holarctic Marmots as a factor of Biodiversity.
Rumiantsev V.Yu;, Nikol'skii A.A. & Brandler O.V. eds.,
Abstracts, 3d Conference on Marmots (Cheboksary, Russia, 25-30 August 1997),
Moscow ABF 1997, 216p., 30-31 (Russian), 150 (English).



THE FLORA OF MARMOTS (MARMOTA SIBIRICA PALL.) BURROWS ON EASTERN KHANGAI (MONGOLIA)


N.P. Guricheva, P.P. Dmitriev

Botanical Institute, Russian Academy of Sciences, St.Peterburg, Department of Biology Moscow State University, Russia


The fauna of marmots mounds consists of 129 species, 26 families, 85 genuses of higher vascular plants. The most numerous families are Asteraceae (21), Poaceae (17), Fabaceae (12), Rosaceae (5), Chenopodiaceae (4), Ranunculaceae (4).and the most numerous genuses were Artemisia (11 species) , Stipa (4), Potentilla (4). The majority of species is xerophytes and mesoxerophytes . With respect to abundence index the species of plants may be obligate (100-80% frequency), semi-obligate (50-70%), rare and occasional (1-2%). The group of character consists of species from first three groups, the character species are absent in the communities of background. The category of asonal species, which are present on all types of steppes, was picket out too. There are 23 such asonal species: Rheum undulatus, Agropyron cristatum, Artemisia changaica, Potentilla bifurca, Leymus chinensis, Galium verum and other. There are no asonal species among 28 obligate one. The greatest number of obligate species (20) was noted in dry steppes with Caragana microphylla and Stipa krylovii. The numbers of obligate species decrese and the numbers of rare species increse with slope upgrade. Almost all of obligate and semi-obligate species seemed to be dominant on the background, or on the neighbouring zone (it is noted by Zimina, Zlotin, 1980).

The partial floras of burrows on different zones are similar. A high similarity Jaccard coefficient is shared by two partial floras in the neighbouring zones (0,45 - 0,50). But the compositions of obligate and semi-obligate species differ significantly. Every partial flora ot the definite zone has character species, but there are only two species that are absent on the background everywhere.

The most character species for marmot burrows (for fresh mounds first of all) are the steppe explerents such as Dontostemon integrifolius, Artemisia palustris and the ruderal species from the families Chenopodiaceae (Axyris amaranthoides, A. hybrida, Salsola australis, Chenopodium album), Brassicaceae (Lepidium densiflorum), Boraginaceae (Lappula echinata). These species of plants are character not only for marmots burrows, but for burrows of other species, they are character for zoophytophtora (Guritceva, Dmitriev, 1983). The presence of these species indicates the late disturbance of steppe cover by animals.

The character perrennial plants are the following species: Urtica canabina, Panzeria lanata, Saussurea salicifolia, etc. But these species are rare.



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