Summary Recent, rapid and often underestimated landscape changes have occurred over large areas in Mediterranean Europe. They are the result of major rural depopulation. Old photographs of landscapes taken at the beginning of the twentieth century (i.e. old postcards) and present‐day photographs taken at the same places were compared in a 2500‐km2 area of southern France. Vegetation changes were analysed using transition matrices. During the 80‐year study period, land uses and vegetation changed dramatically. Woodland cover and tree height increased; but in contrast, the extent of cropped lands and rangelands decreased. Forest spread was heterogeneous, depending on initial composition of the vegetation, and locally dominant ecological and socio‐economic conditions. Our data show that a Mediterranean forest can re‐establish under humid climatic conditions and spread within a century, despite severe prior exploitation over several decades. These dramatic changes are liable to have biological and ecological consequences (e.g. spread of woodland species, threat against open habitat species, fire regime modification, deterioration in water resources), some of them being already perceptible.

High variation in laying date and clutch size of the blue tit between a Mediterranean mixed habitat on the mainland, southern France, and a sclerophyllous habitat on the island of Corsica is hypothesized to be related to differences in the food supply. The diet of the nestlings and feeding frequencies were studied using camera nestboxes and electronic chronographs. Food items brought to the nestlings were much more diverse on Corsica than on the mainland, including many fewer caterpillars and a wider range of taxa. However, when expressed as a volume index, prey items were on average larger on Corsica than on the mainland. Feeding frequencies were significantly lower on Corsica. A good correlation was found in both habitats between laying date and the caterpillar peak date, although both the leafing development of oaks and the peak of abundance of caterpillars occurred 3 weeks later in the Corsican sclerophyllous trees than in the mainland deciduous ones. Differences in the feeding ecology of tits between the two habitats are discussed in the light of the evergreen habit, which means that only 30% of leaves are available for phyllophagous insects instead of 100% in deciduous trees. the combination of a late and low food supply in evergreen trees is the best explanation for the differences in breeding traits betwen the two populations.

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In the context of steady CFD computations, some numerical experiments point out that only a global mesh convergence order of one is numerically reached on a sequence of uniformly refined meshes although the considered numerical scheme is second order. This is due to the presence of genuine discontinuities or sharp gradients in the modelled flow. In order to address this issue, a continuous mesh adaptation framework is proposed based on the metric notion. It relies on a L p control of the interpolation error for twice differentiable functions. This theory provides an optimal bound of the interpolation error involving the Hessian of the solution. From this estimate, an optimal metric is exhibited to govern the adapted mesh generation. As regards steady flow computations with discontinuities, a global second order mesh convergence should be obtained. To this end, a higher order smooth approximation of the solution is reconstructed providing an accurate and reliable Hessian evaluation. Several numerical examples in two and three dimensions illustrate that the global convergence order is recovered using this mesh adaptation strategy.

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