Temporal transformation some of high-mountain plant communities in Aktru valley (Altai Republic) as a result of climate change

The analysis of long-term dynamics of two high-mountain phytocoenoses of Aktru valley (Altai Republic) growing in different landscapes shows that the species compositions, horizontal and vertical structure as well as ecological features of communities have undergone various modifications. The most perceptible changes for the period of2000-2011 have been revealed for the community occupying the lateral side of moraine near the glacier body; this fact is connected to the intensifying glacier melting at the ablation zone and decreasing environmental influence of the glacier to the adjacent territory. The changes in periglacial zone were reflected at considerable increase in substrate humidification; that was ascertained by the method of ecological scales. Microclimate change caused disappearance of ultra-oreophytes and mountain-steppe plant species. Biomorphological transformation of the community is proceeding from predominance of small cushion life forms, to prevalence of prostrate life forms under essential growth of the ground coverage. Pinus sibirica turned from procumbent (elfin wood) to arboraceous life form. Transformation of the alpine meadow situated out of the zone of influence ofglacier body for the period of 1993-2010 has extended over the gradual modification of the plant community structure, increase in species quantity and herbaceous layer height, with relatively constant optimums of plants on such ecological factors as moisture, nutrient richness and salinity of substrate. These changes reflect the gradual shift of the mountain belts as a result of annual temperature growth. The results of our research have revealed that the most significant transformation of the vegetation connected with climate features change can be observed in the vegetation of the moraines at the ablation zone of glaciers.

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