The influence of natural and anthropogenic factors on the floristic features of the northern coast Nile Delta in Egypt

The Egyptian Mediterranean sand dunes are being lost due to recent excessive unplanned anthropogenic interventions that caused a modification in floristic composition. The present study provides a description of the floristic inventory and plant clusters in coastal dunes in relation to natural and human factors. Floristic sampling was carried out in nine transects along Nile Delta coast, a total of 55 plots were randomly placed and data on natural and anthropogenic factors were measured for each plot. Agglomerative Hierarchical Cluster allowed to identify four plant clusters: (A) Elymus farctus-Silene succulenta, (B) Echinops spinosus-Moltkiopsis ciliata, (C): Stipagrostis lanata-Echium angustifolium and (D): Lycium schweinfurthii-Asparagus stipularis. Fish farming, ceramic industry, trampling, agriculture, urbanization, magnesium, total nitrogen, potassium, calcium and organic matter were identified as the most significant key factors for the definition of plant clusters by Canonical Correspondence Analysis. Variance partitioning confirmed that 40% of the variance was explained by both natural and anthropogenic factors. In particular, anthropogenic factors explained only 9% while natural variables 2% of the total variance, whereas the combined shared effect was 29%. The information in this study enables us to establish an effective conservation strategy to prevent further declines in plant diversity along coastal dunes.