PHYTOCENOTIC CHARACTERISTICS OF THE ESTUARY MEADOWS – THE BASIS FOR THE DEVELOPMENT OF SUSTAINABLE REGULATION FOR THEIR USE

Abstract

The aim of the research is to determine the phytocenotic features of estuary meadows of the northwestern part of the Caspian lowland for rational regulations development of their use. Material and Method: the materials on the state of natural estuaries of Volgograd region, accumulated as a result of their regular observation in the system of monitoring conducted by scientists of VNIIOZ since 1972 were used. The method of landscape-ecological profiling of estuary areas within the geographical borders of the north-west of the Caspian lowland was applied. On large deeply cut estuaries with a difference of marks between the contact zone of meadow and steppe vegetation to the lower ones in the central tiers within 1.0–1.6 m, the transect-catenary method with cenoses phytoindication, the boundaries between them was used and the yield of grass stands in the phase of bluegrass hay ripening was determined. Results: according to the flooding parameter, three categories of meadows are distinguished – flood-free and meadows with short-term, medium-term, long-term period of flooding. In turn, meadows with mid-term flooding period are divided into four groups: meadows with signs of xerophytization, greening, hydrophytization, and halophytization. Meadows with long-term flooding period were divided into waterlogged and boggy meadows. The direction of changes in the soil-reclamation state of estuaries was determined by the presence and composition of indicator plant species. In accordance with the accepted evaluation criteria estuary meadows are divided into four categories by the degree of degradation and suitability for further exploitation: the first one includes meadows retaining the potential of coenopopulations, the second one includes meadows of medium degree of phytocenoses degradation, the third one includes meadows with deep deformation of phytocenoses, and the fourth one includes meadows totally degraded in the state of the irrigation network, the degree of soil salinization and the deformation of the indigenous phytocenoses. Conclusion: the ecological and reclamative state of estuaries determines the forms (intensive, semi-intensive, extensive) and the modes of their use taking into account the response of phytocenoses to various species and the degree of anthropogenic load.

Keywords

• meadow irrigable estuaries
• phytocenoses degradation processes
• meadow categories in the system of economic use
• meadows with long period of flooding
• agricultural land
• irrigation
• monitoring