Impact du feu sur la stratégie de régénération d’espèces végétales forestières méditerranéennes

Abstract

Impact of fire on the regeneration strategy of Mediterranean forest plant species. The present study was carried out in the Chrea National Park (Algeria). The main objectives were : understanding forest fire risks, appreciation of the ecological dynamics of the park’s forest ecosystems and evaluation of their resistance to frequent fires. Two species groups, characteristic of the Mediterranean ecosystems and representative of the two main post-fire regeneration strategies : the resprouting strategy, designated by R+ (Quercus suber and Calycotome spinosa) and the non-resprouting strategy, designated by R-(Genista tricuspidata, Cistus salviifolius, Pinus halepensis and Cedrus atlantica), were analysed in two different sites (burned and not burned). The following elements (C, N, P, Ca, Mg, K and Na), present in the soil and the studied plant leaves, were measured and compared with one way-ANOVA analysis. Results showed that the two species groups (R+ vs R-) adopted a different behaviour in respect to fire effect. In the R+ group, four of the seven considered elements (N, K, P and Na) showed significant differences between the two sites. In the R-group, a single element (P) showed a significant difference. These results suggest that the species nutrition behaviour in the post-fire succession process aims to an optimal utilization of soil nutrients, and the vegetation recovery in the early years after fire has an important ecological role in the mobilization of nutrients and their storage in the biomass.