Rangeland restoration in Jordan: Restoring vegetation cover by water harvesting measures

Abstract

Restoration of the degraded rangelands in Jordan using mechanized water harvesting and native species planting has become key to enhancing and maintaining the productivity and resilience of fragile ecosystems. A balanced interaction between the rangeland's hydrology and vegetation states is vital for achieving long-term sustainability. To gain a better insight into the impact of restoration on surface runoff and erosion and its role in recovering the ecosystem functions, we used the Rangeland Hydrological and Erosion Model (RHEM) to simulate various vegetation scenarios. Our research aims to understand the rangelands' water and sediment dynamics and the vegetation transition states of the ecosystem through evaluating the current (degraded) situation, assess the restoration approach on improving the degraded status (restored), and investigate the long-term sustainability of the restoration approach compared with historical rangeland conditions (baseline). Several scenarios were developed with rangeland experts, local community representatives, and measurements at protected and restored areas to represent the rangeland conditions. We found that restoration of the degraded Badia areas will decrease annual surface runoff from an average of 23.5 to 19.1 mm/year and soil erosion rate from 3.3 to 1.3 tons/ha. With time, restoration can bring back rangeland water and sediment dynamics closer towards the baseline conditions, which were 16.9 mm/year runoff rates and 0.85 ton/ha/year soil loss. The results indicate that restoration is a promising methodology to restore the degraded ecosystem and approximate the environment's historical hydrological regime.