Spatio-Temporal Assessment of Vegetation Dynamics in the Zouagha Forest, Northeastern Algeria (2000-2020)

Abstract This study aims to assess the spatio-temporal dynamics of vegetation in the Zouagha Forest, located in northeastern Algeria, over the period 2000-2020, taking into account the degradation induced by the complex interactions between biotic, abiotic, and anthropogenic factors. The analysis of vegetation indices, notably the NDVI (Normalized Difference Vegetation Index), EVI (Enhanced Vegetation Index), and SAVI (Soil-Adjusted Vegetation Index), for the years 2000, 2010, and 2020 reveals divergent trends. The NDVI shows a slight increase, rising from 0.20 in 2000 to 0.33 in 2020, suggesting a moderate regeneration of the vegetation cover. In contrast, the EVI records a notable decline, dropping from 0.38 in 2000 to 0.30 in 2020, indicating a continuous degradation in vegetation quality. Additionally, the SAVI shifts from −0.10 to 0.07, reflecting a modest improvement, yet the vegetation remains weak in terms of density and quality. This divergence between the indices suggests a spatial variation in vegetation conditions, indicating a growing heterogeneity in vegetation distribution across the forest. This phenomenon is exacerbated by unfavorable climatic conditions, such as reduced rainfall and rising temperatures. These changes, combined with anthropogenic pressures such as deforestation, greatly limit the forest’s natural regeneration capacity. Moreover, pest attacks, particularly by ( Lymantria dispar ) and ( Tortrix viridana ), contribute to uneven degradation of the forest ecosystem. These findings highlight the urgency of developing sustainable management strategies, incorporating soil restoration and water resource management, to strengthen the ecological resilience of the Zouagha Forest in the face of growing challenges posed by climate change and human pressures.