Seasonally Dry Tropical Forests: Savannas, woodlands and dry forests in Africa

摘要: Introduction In Africa, the term dry forest covers vegetation types dominated by a more or less continuous tree cover (70%), experiencing pronounced drought during than three months per year, and occurring within savanna biome. They may be called (open) woodlands (dense) forests according to density understory structure (Menaut 1983). The Yangambi classification establishes following (Boughey, 1957a, b; Monod, 1963; Aubreville, 1965). A woodland has an upper stratum of deciduous trees small medium size, with their crowns touching above sparse woody understory. Tree is high enough affect herbaceous which differs floristically from adjacent savanna. ground layer consists grasses, herbs suffrutescent plants in sufficient allow for annual burnings. canopy tends one very few species. forest, strictly speaking, defined as closed stand several strata. grass layer, when present, weak discontinuous, only allowing episodic fires. most cases, are whereas composed evergreen and/or shrubs differ floristically. multispecific often devoid dominants. both woodland, species make up present but never dominant surrounding Some authors have considered tropophilous extension rain adaptations xeric conditions characteristics stems not leaves (Schnell, 1976–7).