Correlating Vegetation Cover and Biomass of a Managed Range Reserve with NDVI of SPOT-5 HRV

This study investigates the relationship between the Normalized Difference Vegetation Index (NDVI), derived from a high-resolution satellite imagery of SPOT-5 HRV, and vegetation biomass and cover of a protected range reserve in the Jordanian Steppe. Eighty locations inside a range reserve were sampled to determine the cover and biomass of herbaceous and shrubby species. The percent cover of herbs was visually estimated while the linetransect method was used to measure the canopy cover of shrubs. The above-ground biomass of herbs was determined by clipping, whereas the biomass production of shrubs was estimated using the reference unit technique. All sampling points were recorded by a Global Positioning System (GPS), and the corresponding NDVI values of these locations were extracted form the HRV imagery then correlated with estimates of above-ground biomass and vegetation cover. Significant correlations were found between NDVI on one hand and both vegetation cover and total above-ground biomass on the other with R2 values of 0.79 and 0.77, respectively. For prediction purposes and potential application of productivity estimates, thirty locations were sampled to validate the output relationships between above-ground biomass and vegetation cover and the remotely sensed NDVI. Significant correlations occurred between predicted and estimated parameters with R2 values of 0.71 and 0.57 for above-ground biomass and cover, respectively. Results also showed good productivity levels after protecting the rangeland for four consecutive years, indicating a good potential of rangeland recovery under proper management