MIKORIZA ON THE DIFFERENT-AGED DUMPS OF ACCERMANOVSKY IRON-SOLID DEPOSIT (STEPPE ZONE)
Mycorrhiza is the most important symbiosis in which plants and fungi are involved. When environmental conditions change, the equilibrium in natural complexes shifts, including mycorrhizal disturbances. Such violations lead to serious consequences, such as degradation of plant communities, reduced availability of elements necessary for plants. One example of such territories is industrial dumps. The restoration of vegetation on heaps is extremely slow. In this connection, a great interest is the study of mycorrhizas in plant communities that are formed on disturbed lands. The features of mycorrhiza formation of herbaceous species in plant communities formed in the process of self-growth at different-aged (3-36-year-old) sections of the Ackerman iron ore deposit dumps located in the Orenburg region (steppe zone) are studied. The rocks of the dumps are characterized by a very low content of elements of mineral nutrition available for plants: nitrogen, carbon, phosphorus. Studies have shown that in the roots of most herbaceous plants there is arbuscular mycorrhiza. In plant communities of 3-20-year-old dumps mycorrhizal species constitute 35.3-44.0%, by the age of 27 their proportion increases to 90.9%. All the studied mycotrophic species belong to weakly-microtrophic species. The low proportion of mycorrhizal plants and the poor development of mycorrhizas in plants growing on dumps in the steppe zone is due to the inadequate content of elements of mineral nutrition in rocks forming dumps, high rockiness of rocks, and insufficient moisture. It has been established that mycorrhizal parameters depend on edaphic conditions and on the degree of formation of plant communities.