Identifying vegetation indices as the rational spectral indicators of vegetation state under conditions of laboratory experiment

Abstract

For the vegetation classes, which cover the ground surface with a rather small area and studied by means of the ground-based remote sensors it’s necessary to select the suitable spectral indices, which cloud responded in a fast and effective way to dynamic environmental conditions induced by the different stress factors. The vegetation indices (VIs) can be such indicators calculated by the mathematical operations using reflectances in the different spectral ranges measured by the field remote sensors, i.e. spectroradiometers. Application of VIs allows identifying these changes of vegetation state, which aren’t visible at the visual observation. In order to select these VIs we have conducted the laboratory experiment with the cultivation of durum spring wheat variety “Diana” at the different higher seeding rates to provide by this way, first, the fast 100% plant cover, and, second, establish the stressed conditions for the plants. During this experiment the gasometric and spectrometric observation of the constantly growing phytomass carried out, when the measurements of intensity of СО2 absorption and release by the plants in process of photosynthesis/respiration and spectrometric ones have been performed practically simultaneously that allowed further calculation of VIs. Three vegetation indices such as MTCI, Clrededge and Clgreen were identified as the most sensitive to the changes of vegetation state and, thus, they can serve as the proper spectral indicators of vegetation condition, which are extremely necessary to develop the technique of estimating the variables of carbon cycle in the different ecosystems using satellite data and field measurements, improve of assessment for the climatic effects at the regional and local levels and estimating the IAEG-SDGs indicators of sustainable development.