Research Sites

Figure 1         Distribution map of the semi-arid savanna sites (dashed red rings) and humid savanna sites (solid blue rings) in tropical, sub-tropical and warm temperate regions, that we are using for GEST. Sites were chosen using recent updates of the Köppen-Geiger Climate Classification (see Kottek et al. 2006, Peel et al. 2007). Note that there is an additional arid site in North America (stippled orange ring), and that the dashed red circle in North America represents an intermediate site on the cusp of the humid and semi-arid savannas. The sites in North America were chosen to consider how savanna tree species’ seedling growth traits change along an increasing rainfall gradient that moves from west to east across the continent. The North American sites are also the only sites situated outside the 30^o parallels (dashed lines) and therefore more typically warm temperate than the other sites, but all field sites share hot summers and their grass flora are dominated by C4 species.