The actual landscape of the Padana Plain is the outcome of the thousands of years of growth and change. The fertile land has been deforested, the rivers dammed up by their banks, the marsh area reclaimed. What was once a vast forest with its marsh land has become a grassed plain. The trees, once commanders absolute of the space, have thickened into woods in the few areas left to them. The remaining survive as secular trees in isolation, the last traces of the antique forests, or as cultivated trees on the confines of the land reinforcing ditches and canals and marking boundaries, supplying wood, leaves, fruit and precious goods for the farmer. Even the grass may seem a forest when observed close at hand.