SPECTRAL CHARACTERISTICS OF DESERTIFICATED PASTURES OF BLACK LANDS (KALMYK REPUBLIC)
UDC 631.1: 631.4:631.6:581.5: 528.7:528.8:574.46
Yuferev V.G., Tkachenko N.A., Sinel’nikova K.P. SPECTRAL CHARACTERISTICS OF DESERTIFICATED PASTURES OF BLACK LANDS (KALMYK REPUBLIC) // Arid ecosystems. 2022. V.28. № 1 (90). P. 65-72. | PDF
Geosystems of the desert territories of Kalmykia in modern conditions function in conditions of increasing anthropogenic impact and intensity of negative weather events, including the impact of dust storms, which often leads to a significant decrease in pasture productivity, a decrease in the feed base and a significant reduction in livestock. In this regard, it is relevant to determine the spectral characteristics of desert pastures by ground methods, which provides not only the detection of the reflected energy distribution over the spectrum frequencies, which in itself is important for subsequent verification of remote sensing data of pastures, but also the possibility of obtaining the values of normalized indicators, both for plant communities and for specific plants and soil types with the formation of a spatial data base. The objects of the study are the natural phytocenoses of desert pastures of the Black Lands at the landfills: «Smushkovo», «Molodezhny», «Privolny», «Dl. Sagi» and «Tavn-Gashun». Geobotanical and spectrometric studies were carried out at these polygons and spatially determined data on the spectral characteristics of plant communities were obtained. Spectrometric studies of phytocenoses are carried out to assess their condition on the basis of spectrosonal surveys, both ground-based and remote. To present the results of the assessment of the spectrometric characteristics of the vegetation cover of the downed pastures: the predominant communities at the landfill and «Tavn-Gashun» were selected: bluegrass with Descurania sofia (Poa bulbosa+Descurainia sophia) with a projective cover of 45%, grasshopper bluegrass (Poa bulbosa-Stipa capillata) – with a projective cover of 40% and open soil (slightly humus sand). The studies were carried out using the PSR-1100 field spectroradiometer. The results of studies of the spectrum of reflected radiation of plant communities and underlying soils allowed us to establish the characteristic features of the distribution of reflected and absorbed energy, to compile a catalog of individual spectra and normalized indicators for them. Individual spectral characteristics were established for the phytocenosis Poa bulbosa+Descurainia sophia, the average value of reflected energy in all spectral ranges is 20.2 MW/(m2×sr×nm), the standard deviation of reflected energy is 9.90, the vegetation index NDVI = 0.208, for Stipa capillata, the average value of reflected energy in all spectral ranges is 20.5 MW/(m2 sr nm), the standard deviation of reflected energy is 12.36, the vegetation index NDVI = 0.316, for Calligonum aphyllum, the average value of reflected energy-the reflected energy in all spectral ranges is 47.2 MW/(m2×sr×nm), the standard deviation of reflected energy is 9.81, the vegetation index NDVI = 0.354. For soil, the average value of reflected energy in all spectral ranges is 30.3 MW/(m2×sr×nm), the standard deviation of reflected energy is 9.28, the vegetation index NDVI = 0.106. The highest average value of NDVI was noted for Calligonum aphyllum.
Keywords: geosystem, analysis, desertification, degradation, spectrometry, satellite images, phytocenoses, verification, vegetation indices, albedo.
Financing. The work was carried out within the framework of the State Task of the Federal Research Center of Agroecology of the Russian Academy of Sciences No. 0713-2019-0001 “To conduct theoretical and geoinformation modeling, monitoring, forecasting of degradation processes of components of agroforestry landscapes based on aerospace research in forest-steppe, steppe and desert zones and to develop ways to manage anti-degradation agroforestry technologies to prevent desertification of lands, increase their fertility and form an ecological framework” (state registration No. AAAAAA-A-116122010038-9).