The rate of afforestation is increasing worldwide and has represented a common land use and a very important resource for centuries. The use of exotic species in the afforestation process may have a negative impact on ecosystem function and structure, including changes in shading, microclimate, nutrient cycles, and water balance, which may, in turn, affect biodiversity.  The objective of this paper was to document and investigate the impact of forest plantations that use alien plants on the native ground-dwelling fauna, specifically using spiders as bioindicators. Spider species showed a great difference in both univariate measurements (diversity indices, richness and evenness) and multivariate analysis (species composition and indicator species). Five spider species were newly recorded in Egypt during this study; four of them were found in the forest habitat (Micaria dives, Odontodrassus aravaensis, Pholcus opilionoides and Scytodes univittata) while Halodromus patellidens was recorded in the control area. The experimental nature of this study confirmed that assessing the risks of forest plantation activities is urgently needed before introducing any species. It highlights the fact that the use of endemic trees is preferred in order to avoid altering native diversity.