Classification and ordination of lime trees in the south of the Tyumen Region

The paper contains a classification of lime trees according to the method of Brown-Blanke and ordination based on isolated syntaxonomic units in the southern part of the Tyumen Region. The material for this study was 115 geobotanical descriptions of the lime trees in the southern part of the Tyumen Region. Syntaxonomic diversity of lime trees on the territory of three regions in the south of the Tyumen Region in the system of ecological and floral classification includes 8 associations and 6 variants belonging to 3 orders, 3 unions and 2 classes: Asaro europaei - Abietetea sibiriacae and Brachypodio pinnate - Betuletea pendulae . Forests of the selected associations and variants are distributed by various relationships to humidification conditions from the more humid to the steppe forests. To study the syntaxonomic diversity of lime trees, a multifactorial gradient analysis was used, where a combination of several environmental factors was simultaneously considered. Average values for four soil scales of D.N. Tsyganov and two scales of A.Yu. Korolyuk discovered 12 patterns of syntaxonomic units that revealed a certain pattern of distribution on the ordinate axis with concentration from dry forests to moist forests. The main gradient factor of location in the ecological area of lime trees associations is the presence of moisture in the soil.