ABSTRACT
Tropical savanna is defined as having a discontinuous C3 woody perennial overstorey and a near-continuous herbaceous and grassy C4 understorey. Savannas are by definition distinct from grassland (absence of or limited woody plant cover) and forest ecosystems (absence of or limited grass cover). This ecosystem occurs on nearly all major land masses within the tropical and subtropical belt around 30° north and south of the equator (Hutley and Setterfield 2008). Savannas cover 20 per cent of Earth’s continental land mass and account for 30 per cent of global net primary productivity. Tropical savanna is the second largest tropical ecosystem after rainforests and occurs across the seasonal tropics of Australia, Africa and South America (Figure 21.1) with a distribution of greater than 27.6 million km2 (Hutley and Setterfield 2008). The two largest uninterrupted savanna landscapes are the Australian savanna and the South American cerrado/llanos of Brazil, Colombia and Venezuela.
