ABSTRACT
Whereas Chapter 8 examined patterns of life form (biomes) throughout the Earth, Chapter 9 examines patterns of species diversity, which includes species richness and endemism. The species gradient with latitude is the first pattern identified. A map showing “global hotspots of biodiversity” is presented, with the hottest of the hotspots identified as Tropical Andes, judging by the number of vascular plant endemic specie. A “constraint hierarchy” is presented, which outlines the factors constraining plant or animal distribution at global, regional, and local levels. Within the constraint hierarchy at the global level, Liebig’s Law of the Minimum and Shelford’s Law of Tolerance are prominent. At the regional level dispersal, vicariance, and speciation are highlighted as important processes. It is only at the local level that processes like competition, predation, and symbiosis come to prominence in determining why species are where they are. This is interesting because most of the focus in ecology has been on competition and predation and other local level effects, often to the exclusion of macroecological patterns.
