The effect of Stipa tenacissima tussocks on some soil surface propertiesunder arid bioclimate in the southern Tunisia

摘要

In arid and semi-arid areas of the Mediterranean basin, opensteppes are dominated by alfa grass (Stipa tenacissima L.) tussocks which playa crucial role in maintaining ecological ecosystem integrity. In this study, we ana-lyze the effects of S. tenacissima tussocks on soil properties in an arid S. tena-cissima steppe in Southern Tunisia. Our main objective is to test whether S.tenacissima microsite is able to ameliorate soil surface properties in semiariddegraded steppes. Soils under S. tenacissima tussocks have higher organicmatter, nitrogen content, phosphorus and CO2 efflux than those from openareas. S. tenacissima tussocks improve also physical soil features by increasingsoil water content and infiltration capacities underneath the canopy. This studyreinforces the idea that fertile patches and particularly S. tenacissima tussocks,by their positive effect on the soil, can be of particular importance for successfulrestoration in degraded arid and semiarid steppes.