Fig. 5. Landscape structural dynamics in long-term historical simulations of the pastures Bullatonne, Rionde, Pré aux Veaux, and Planets-Cluds. Simulations start from clearings in 1100 AD and follow historical time series of grazing and climate. The four phytocoenosis types used for display are defined in Table 3. The landscape aggregation index AIL is computed after He et al. (2000) as the weighted mean of aggregation indexes AI computed for each phytocoenosis type. AI assumes that a class with the highest level of aggregation is comprised of pixels sharing the most possible edges (simple clumped pattern). A class whose pixels share no edges (completely disaggregated complex pattern) has the lowest level of aggregation.