Forest managers are sometimes "stressed" by having to measure the plant species diversity in forests. Nevertheless, it is necessary if this parameter is to be included later in management. From an applied point of view, two plot designs (square or circle) that we used to assess diversity in various types of managed chestnut ecosystems (grove, forest, coppice, and reafforestation) are discussed.
The results suggest that both designs were efficient. Moreover for each of these two designs we also report findings about changes in species richness: (i) species richness is considerably influenced by the management type in some cases (coppicing favours species richness for few years after the clear-cut, whereas abandonment induces a loss of species richness, etc.); (ii) biodiversity in previous chestnut stands modified by tree plantation is quite low and is not much influenced by the origin of the tree species used (native or introduced).