 Trees here have adapted to the warm arid climate by shedding leaves in the dry season to reduce evapotranspiration, and some species such as the baobab store large amounts of water in their bulbous trunks.There is a very high rate of species endemicity in all the western dry deciduous forests of Madagascar, for both flora and fauna; this rate is thought to be higher than for the eastern rainforests, although the biodiversity, while extremely high, is slightly less than the eastern counterparts.Geologically the tsingy formations have numerous caverns (used by early tribesmen) and karst formations, which provide underground water storage.