Biomass estimation of rangelands in the Eastern Highlands by remote sensing indices

The rangelands of the High plateau of eastern Morocco constitute an important supplement to the feeding of sheep and goats. Estimating phytomass production from these rangelands during the growing season is useful for managers of pastoral areas. The objective of this study is to test several vegetation indices resulting from remote sensing to propose the most appropriate vegetation indices for phytomass estimation of Moroccan rangelands. In this study, field data collected during April 2018 and eight vegetation indices (ARVI, DVI, IPVI, MSAVI, NDVI, RVI, SAVI and TSAVI) from the Sentinel-2 satellite images taken in April 2018 are used. Correlations between phytomass and each of these vegetation indices were performed to identify the best estimator. The results showed that rangeland phytomass ranged from 0.02 to 4.71 with an average of 0.84 tons per hectare in the studied sites. Vegetation indices highly correlated with phytomass are ARVI, IPVI, NDVI, RVI and SAVI. Polynomial models were better than linear models. The best model of phytomass estimation was RVI followed by, IPVI, NDVI, ARVI and SAVI with R2 of 0.84; 0.82; 0.82; 0.81 and 0.80 respectively.