ИСТИНА

Plants that are typical of fertile soils tend to have relatively thin leaves with a large specific leaf area. On the other hand, at the intraspecific level, leaves increase in size upon the enrichment of soils with mineral nutrients, which may lead to a reduction of specific leaf area. The question of how an increase in soil fertility influences the increase in the size of leaves without changing other traits remains open. In order to evaluate the consistency of the intraspecific response of plants to changes in the nutrient enrichment of soil with the general tendencies of change in leaf traits in plant communities that differ in production, an experiment was conducted in alpine plant communities in the northwest Caucasus. Changes in the properties of alpine plant leaves in plant communities of four types after longterm application of mineral nutrients (NP and lime) were studied. It was shown that, under the nutrient enrichment of soil, the size properties of leaves (area, wet and dry mass) increase in all species except the legume Hedysarum caucasicum. Specific leaf area (SLA) decreases in plants from alpine heathlands and increases in Geranium gymnocaulon, which is the dominant species of Geranium–Hedysarum meadows and plants of snowbed community. After the correction of SLA, taking into account changes in leaf sizes, it was noted that an increase in leaf area decreases SLA in the majority of plant species, and a change in leaf structure under the influence of application of mineral nutrients leads to an increase in SLA. Species which increase SLA greatly increase their biomass under addition of the nutrients.