Thèse-EliseBuisson-Discussion

General Discussion The discussion is organized following the introduction outline. I answer the basic questions set in the introduction by summarizing A) the results of experiments in La Crau B) the results of experiments in California coastal prairies C) I then draw conclusions for both sites together and detail how these results contribute to ecological theory and/or to ecological restoration. 1. Impact What is the impact of strong exogenous disturbances on Mediterranean herbaceous plant communities that have evolved with regular endogenous disturbances for centuries? A) Exogenous disturbances have a great impact on both Mediterranean herbaceous plant communities studied. Cultivation has a great impact on the steppe of La Crau which varies depending on cultivation intensity. Cereal cultivation represents a moderate degree of disturbance compared to melon on, and this is still observable decades after cultivation abandonment. Both types of cultivation changed a) the physical and chemical soil parameters; b) the vegetation composition, richness and structure; and c) the species composition of the actual seed bank (Fig. 41). a) changes in physical and chemical soil parameters: Cereal cultivation involved surface plowing, fertilization and some stone removal, and has had a moderate impact on soil parameters: it has increased pH, potassium, and clay. Melon cultivation involved deep plowing, fertilization, irrigation, treatments and stone removal, ...