Egyptian Journal of Aquatic Biology & Fisheries Zoology Department, Faculty of Science, Ain Shams University, Cairo, Egypt. ISSN 1110 – 6131 Vol. 23(3): 385 –399 (2019) www.ejabf.journals.ekb.eg Physical and chemical characteristics of mangrove soil under marine influence. A case study on the Mangrove Forests at Egyptian-African Red Sea Coast. Abdelwahab A. Afefe¹*, Mohamed S. Abbas², Amira Sh. Soliman², Abdel-Hamid A. Khedr³ and El-Bialy E. Hatab¹ 1- Nature Conservation Sector, Egyptian Environmental Affairs Agency (EEAA), Egypt. 2- Natural Resources Department, Faculty of African Postgraduate Studies, Cairo University, Egypt. 3-Botany and Microbiology Department, Faculty of Science, Damietta University, Egypt *Corresponding author: abdoafefe@hotmail.com ARTICLE INFO ABSTRACT Article History: Received: July 7, 2019 Accepted: Sept. 6 ,2019 Online: Sept. 9, 2019 _______________ Keywords: Mangrove Red Sea Soil Protected Area Avicennia marina Rhizophora mucronata. The present study provides an analysis the growth performance of mangrove forests (Avicennia marina and Rhizophora mucronata) and the concentrates on the environmental factors (soil) that affect on the mangroves along Egyptian-African Red Sea coast. The growth performance of R. mucronata was higher in association with A. marina than in pure stands. Moreover, A. marina trees growing in association with R. mucronata were taller than plants growing in pure community. Plants growing (size index) at high tide attained the highest values of growth attributes. In comparison, A. marina growth attributes differed between the three locations of the three tide levels. The highest values of the growth parameters were recorded for A. marina growing at the medium tide in pure stands. However, the growth values of A. marina growing in mixture with R. mucronata were higher at low tide than those at either high or medium tides. The total mean of Soil Bulk Density (SBD) of the A. marina (1.24 g cm³) was higher than that of the R. mucronata (1.16 g cm³) and mixed stands (1.12 g cm³). The results shows that both ordination techniques clearly indicated that electric conductivity, CaCO3, K+, Ca++, Cl-, Na+ and Mg++ were the most important parameters determining the current distribution of mangrove pattern in the Egyptian Red Sea coast. The results showed that there is a similarity between the soil samples in different of the study locations as whole area is a coastal. In the current study the variability of ecosystem structure and function is generally a product of interactions between its different components. In the extreme arid environmental conditions of arid lands these interactions are of high significance, so that slight irregularities in one component of the ecosystem are likely to lead to substantial variations in others, so creating distinct micro habitats. INTRODUCTION Mangrove forests are tropical trees and woody shrubsgrowing at the intertidal zone of highly productive ecosystem of the tropical and subtropical regions (Kathiresan and Bingham, 2001; Giri et al., 2011). Mangrove forests cover approximately 137,760 km 2 worldwide (Giriet al. 2011) and are more productive in terms of net primary production than most other types of forests.