Vegetation dynamics of Algerian’s steppe ecosystem. Case of the region of Tiaret

Abstract

The Algerian steppe routes cover an area of ​​20 million hectares. Their geographical location gives them a buffer zone between the North with a Sub humid climate and the large arid Sahara in the South. The steppe ecosystem is now facing a serious problem of degradation - desertification. The characterization of steppe vegetation and its use as a biological indicator makes it possible to define the evolution of the steppe ecosystem and to identify the changes that have occurred. The objective of the study is to study the evolution of steppe vegetation in the Tiaret region, by using remote sensing data. An approach based on the combination of various studied parameters, by the establishment of a geographical system is adopted. A series of LANDSAT satellite images, covering the period 1987-2016, with seven images is used to produce land use maps. Data from salinity indices SI and NDWI, as well as climatic data are acquired from the google earth engine platform. The results obtained demonstrate a variability of the spatio-temporal distribution of the steppe vegetation of the study area with a tendency to degradation. The canonical correspondence analysis reveals associations between the steppe vegetation cover and the precipitation and salinity parameters, demonstrating a strong sensitivity of steppe vegetation to external hazards.

DOI: http://dx.doi.org/10.5755/j01.erem.74.1.20095