Ecological intercomponent relationships in the natural solonetzic soil complex of the Northern Sarpinskaya Plain (Kalmykia Republic)

Abstract

Thorough soil–geobotanical studies have been performed on a key plot located in the deserted steppe subzone of the light-chestnut–soil zone within the physicogeographical region of the Northern Sarpinskaya Lowland, Kalmykia, along a 64-m-long profile with coupled analysis of microrelief, vegetation, soils, and remote data (detailed Quickbird image). Geobotanical plots, soil trenches, and holes 1–2 m deep have been established along the profile at 1-m intervals. Analysis of the data has showed a close correlation of soils with plants communities (r = 0.72) and loose correlations of these parameters with microrelief (r = 0.42 and r = 0.36, respectively). Some species―Falcaria vulgaris, Limonium caspium, Agropyron desertorum, Stipa lessingiana, Artemisia lerchiana, Festuca valesiaca, and Tanacetum achilleifolium―are never seen on crust solonetzes; the first four species are also never found on shallow solonetzes, and the first two species are never encountered on solonetzic soils. Other species―Kochia prostrata, Artemisia pauciflora, Anabasis aphylla, and Bassia sedoides―are mainly confined to shallow and crust solonetzes and are rarely found on other soil types. The mowing data are well correlated with the normalized difference vegetation index (NDVI) (r = 0.77). The status of vegetation reflected by the NDVI value on the image is clearly determined by edaphic conditions, primarily the soil variety.