Current Growth Conditions of Populus Diversifolia Schrenk and Populus Pruinosa Schrenk in the Syr-Darya Valley

Abstract

In the context of urbanization of territories and the intensification of agriculture, the biological diversity of animals and plants in their habitats is degrading. The purpose of the study is to determine the edaphic factors affecting the growth of Populus diversifolia Schrenk and Populus pruinosa Schrenk, as well as anthropogenic factors affecting their conservation in the Syr-Darya valley (Kazakhstan). For identifying the range of edaphic growing conditions, the analysis of soil samples gathered in different phytocenoses with the dominance or participation of Turanga was carried out. The following results were presented: Physical and chemical analyses of soil samples for the content of humus, mobile forms of easily hydrolyzable nitrogen, phosphorus, and potassium; pH aqueous solution; type, and degree of salinization. Among the 6 sections studied, 4 belong to alluvial-meadow tugai salt marsh soils, 1-to meadow salt marshes, and 1-to alluvial-meadow strongly salt marsh soils. Populus diversifolia has been found to prefer mild (sandy) and fewer saline conditions than Populus pruinosa. Among the negative anthropogenic impacts on the Turanga groves were: Regulation of the runoff of the Syr-Darya, felling of trees, fires, and grazing. The identified cenoflora was represented by 103 species of higher vascular plants. Among them, Chenopodiaceae (18), Asteraceae (18), and Brassicaceae (12) were leading. The indicative role of Turanga was based on its connection to the places of groundwater occurrence.

Influence of Climatic Changes on the Dendrochronological Features of Tugai Forests along the Syr Darya and Ili Rivers in the Territory of Kazakhstan

“…The weather variability of the width of the annual rings is associated with the inter-seasonal variability of the hydrological regime of the floodplain and the time when trees are in a submerged state [13]. It should be noted, however, that the influence of weather conditions on the growth of turanga variegated on the Ili River has increased in recent decades compared to the previous period [14].…”

Plant Diversity and Distribution Patterns of Populus pruinosa Schrenk (Salicaceae) Floodplain Forests in Kazakhstan

“…Floodplain meadow-forest soils developed on elevated areas of the riverine floodplain and the riverine ramparts of the Syr Darya River [16,49]. Fresh and slightly mineralized groundwater was found at depths from 1-3 to 2-5 m. The soil-forming rocks were alluvial deposits of a light granulometric composition.…”

“…Recent publications reflected the results of a study of the floristic composition of turanga woodlands and forests in key areas [14,15] and an evaluation of the soil conditions [16,17]. An assessment of the current state of turanga stands in the southeast of Kazakhstan (the Almaty region) was also conducted [18], which showed the dominance of low-priority, low-field stands that are mainly mature and over-mature in terms of age.…”

Anatomical Structure and Phytochemical Composition of a Rare Species Fraxinus sogdiana Bunge (Oleaceae) Growing in Different Soils in Kazakhstan

“…The results of studies [41,42] obtained by studying the soil cover and soils of the Syrdarya and Ili River Valleys, related to the presented regions, showed the formation of floodplain forest-meadow soils in uniform conditions, the uniformity of their genesis, their profile structure, and the limits of physical and chemical composition indicators. Five transects were laid on the floodplain terraces of the rivers.…”