Abstract
This research was conducted on the protected area of El-Mergueb at M’sila province. The zone of El-Mergueb is located about 180 km south of the capital Algiers, at an altitude from 550 to 800 m, and is characterised by arid climate. The zone of El-Mergueb has a landscape from the steppe to Alfa that lies just as well in the flat ridges hills that in their slopes and in the top part of the ravines. Alfa tenacissima dominates the most geographical space of El-Mergueb. This study is based on the analysis of the homogenous and heterogeneous facies by the determination of the content of calcium carbonate (CaCO3), active calcium carbonate (ACCE) and gypsum through monitoring these chemical parameters during 3 years: 2017, 2018, 2019. Six soil profiles of 15 soil samples collected in the site of study were studied and several chemical soil properties were considered. These factors included: soil pH, calcium carbonate (CaCO3), active total carbonate (CA), gypsum (CaSO4) and electrical conductivity (EC). Principal component analysis (PCA) was used to identify the variations in soil properties. Results showed that there are significant relationships between some soil factors and two PCA axes. The results thus obtained showed that the content of CaCO3 and CA analysed ranged from average to high. The average of gypsum and salinity was low. Floristic diversity defined 284 species. The data on the chemical characteristics of the soil studied have been the subject of a detailed statistical analysis (PCA). Our database consisted of quantitative variables. The implementation of the PCA to the soils studied showed a major dominance of the limestone in the two stations, which explains the alkaline pH and the low concentration of gypsum. Finally, these types of high total limestone are the most observed in the majority of steppe and arid soils.