Evolution of Mediterranean Forest Ecosystems and Impact of Natural and Anthropogenic Disturbances: Case of the Cork Oak Forest- Tlemcen- Algeria

Abstract

Background: Forest cover change continues to be one of the most important topics in global environment discussions and negotiations. In North Africa, there is a broad consensus on forest decline but available information on the extent and rate of degradation has been far lower than needed. The present study uses the example of the cork oak forest of Tlemcen (Hafir-Zariffet forest), North West Algeria, to provide spatially explicit and up-to-date information on forest cover changes. The goal was to fill a knowledge gap in a poorly studied area by determining the extent of changes in forest cover. Methods: Land use land cover maps of 1989, 1999, 2009 and 2019 were classified using Random Forest Algorithm in R software and change assessed via intensity analysis. Results: The results revealed that sparse vegetation was the dominant land cover at the end of the study period, although it decreased from 71.25% in 1989 to 65.24% in 2019. The lowest coverage was water body from 0.47% in 1989 to 0.18% in 2019. Sparse vegetation and dense forest experienced a major decline of 6.01% and 3.22% respectively. On the other hand, open forest (+6.96%), bare areas (+0.37%), settlements (+1.99%) and agricultural (+0.21%) increased. In the LULC transitions analysis, dense forest recorded loss for two consecutive periods (1989-1999 and 1999-2009). The path of conversion was mainly from dense forest to open forest, an evidence of anthropogenic activities. Conclusion: The findings show that the cork oak forest of Hafir-Zariffet suffered multiple pressures, which cause degradation of this natural heritage. These pressures continue to increase the fragility of forest ecosystem and can affect the rehabilitation or even its resilience. In order to conserve the dwindling cork oak forest, a sustainable and effective management which ensures ecological, economic and social balance should be adopted.