2018,    N 3 (33)    

ECOLOGY

Svintsov I., Semenyutina V.

The influence of edaphic and climatic factors on the ecological plasticity of plants Zizyphus jujuba Mill.

In connection with climate change, the perspectives of cultivation of various economically valuable plants in the southern regions of Russia are actual. To expand the existing concept of the distribution area and ecological plasticity of plant organisms of Zizyphus jujuba to stress factors, an ecological test of the small-fruited form of plants was conducted in different edaphic conditions of the Volgograd Region (light chestnut, chestnut soils). The site of ecological testing of Zizyphus jujuba with light chestnut soils (Volgograd) is characterized by medium-thick loamy soils formed on deluvial sediment. The humus content in the root layer is small (0.67-1.15%). The site (Kamyshin, Volgograd Region) is represented by chestnut (homogeneous, buried) light loamy slightly solonetzic soils with a humus content of 1.5-2.5%. Analysis of the influence of climatic parameters of experimental sites revealed their role in the adaptation of plant organisms. The dendrogram of the similarity of distribution areas of Zizyphus jujuba according to climatic characteristics has shown that the climate of the dry steppe areas of the Volgograd region is closer to the climate of some areas of southwest Asia and the Crimea, where the boundaries of the distribution range pass. The interrelation between plants and edaphic factors in the agroecological conditions of the dry steppe reveals an analysis of the differences in climatic characteristics between the distribution points. Materials were obtained that testify to tolerance to low temperatures in the field and during the freezing of plant samples in the climate chamber KHTV-0.22. The northern boundary of cultivation of Zizyphus jujuba, located between 50 ° 4'and 50 ° 5'of latitude and 45 ° 22' and 45 ° 23'E, is established (Kamyshin, Volgograd region). The limits of ecological plasticity of unabi plants have been determined based on the range of factors - extremely low (-37 ° C) and maximum temperatures (+ 40.1 ° C). It is proved that the studied plants under conditions of light chestnut and chestnut soils have a relatively stable water content of the leaves during the growing season, despite high summer temperatures (30-38° C) and a drop in air humidity (up to 25%). Plants of Zizyphus jujuba have a sufficient degree of drought resistance (0.88-0.97) and show the ability to regulate water exchange in the dry-steppe conditions of the Volgograd region in the arid vegetation. The limits of tolerance of Zizyphus jujuba plants to chloride salinity have been experimentally established, which makes it possible to predict their successful growth on soils containing 0.1% chlorine ions.

Keywords: ZIZYPHUS JUJUBA MILL., FORM WITH SMALL FRUITS, EDAPHIC FACTORS, CLIMATIC FACTORS, DISTRIBUTION AREA, ECOLOGICAL PLASTICITY, TOLERANCE, CHLORIDE SALINIZATION, MORPHOLOGICAL STRUCTURE, SOIL SEGMENT