sentences:  In the limestone mountains of Andalusia a detectable role is played by thickets "pluvilunares" and hummocks of common buckthorn ("Rhamnus cathartica").From an ecological point of view, shrubby borders are fundamental in forest ecosystems to guarantee the natural regeneration of the woods, as well as to provide food and refuge for the associated fauna.They are made up of spiny shrubs, depending on the forest and climate, such as gorse, box, thyme, and so on.