Comparative Assessment Of Protected Grazing Areas And Reforestation On Pastoral Quality (Pastoral Value Index, IVP) And Carbon Sequestration In The Steppes Of Djelfa, Algeria

Abstract

Desertification threatens food security in semi-arid regions, particularly in Djelfa (Algeria), exacerbated by climate change and overgrazing. This study aims to comparatively evaluate the long-term effectiveness of two major restoration strategies—Reforestation (R) and Protected Grazing Areas relative to a Control zone (Natural forest). Field measurements were conducted in 2023 on 45 plots (N=15 per treatment), quantifying Overall Coverage (OC), Total Biomass (Phytomass), Annual Forage Production (UF/ha/year), and the Pastoral Value Index (PVI), an indicator of pasture quality. Kruskal-Wallis non-parametric analyses revealed highly significant differences between treatments for all indicators (p < 0.001). Notably, Mise en Défens recorded a significantly higher IVP than Reforestation (p < 0.001), indicating greater resilience and forage quality through natural regeneration. Conversely, Reforestation demonstrated the highest Total Biomass (p < 0.001), underscoring its crucial role in carbon sequestration. These results support an integrated approach in which Mise en Défens is prioritized for pastoral enhancement, and Reforestation for soil stabilization and woody biomass sequestration.