Publications des agents du Cirad


Temporal changes of the botanical and functional composition of Algerian steppes of the Hadj Mechri commune (Wilaya de Laghouat). P2.016

Hammouda R.F., Huguenin J., Taugourdeau S., Nedjraoui D.. 2016. In : EcoSummit 2016 - Ecological Sustainability: Engineering Change. Montpellier : INRA, 1 p.. International EcoSummit Congress 2016. 5, 2016-08-29/2016-09-01, Montpellier (France).

The Algerian steppe that covers 20 millions of hectare is one of the biggest livestock production zone in North Africa. The steppe is impacted by several global changes (climatic change, land-use changes, increase in demography, overgrazing...). The knowledge and the dynamic of this vegetation of this steppe are essential for the different actors involved in the management of this resource. All the actors agree on the fact that the steppe productivity and area decreases. The goal of our study was to understand the dynamic of the rangeland vegetation and its resilience. Our study site was in the Hadj Mechri commune (65.270 ha) in the Laghouat Wilaya (Algeria). The climate is semiarid (average rainfall 315mm per year, CV =31%). We made phytoecological surveys between 2007 and 2013 in the different vegetal formation defined in the beginning of the study (Stipa tenacissima, Lygeum spartum et Stipagrostis pungens). We assessed the botanical composition using a NMDS based on the Bray Curtis distances between the surveys. We used the two first axes the NDMS as indicators of botanical composition. We also used the Raunkier, Noy-Meir and Grime classification to describe the vegetation. We compared these variables between the different years for each formation and all the survey together. We notice a shift in vegetation between 2011 and 2012 on the botanical composition. This shift was also in the functional strategies of the vegetation. Between 2007 and 2011, the species were more geophytes, competitor and arido-active species than the species in 2012-2013. The species in these years were more ruderal, therophyte and arido-passive species. These shifts were more important for Lygeum spartum. We think that this shift were related to decrease in sand and increase in organic matter. This change was correlated with an increase of the vegetation cover and the pastoral value.

Documents associés

Communication de congrès

Agents Cirad, auteurs de cette publication :