Nestedness • Species-Area Relationship • Site Species Overlap • Patch Occupancy • Local Richness • Latitudinal Gradient



Nestedness


Species found in small subsets in any locality are also found in large subsets in other localities.


Species-Area Relationship


Species diversity increases with area sampled.


Site Species Overlap


The sets of species found in any pair of sites increases with proximity (decreasing distance apart).


Patch Occupancy Frequency


There tend to be many species found in a single site (leftmost bin) and in all sites sampled (rightmost bin) and relatively fewer in intermediate occupancy classes.


Limitation of Local Richness


Local species richness cannot be greater than regional richness (gray line), is almost always limited by sampling (black solid line), and is usually partially limited by biological interactions (black dashed line)


Latitudinal Gradient in Richness


Species richness decreases with increasing distance from the equator. With the exception of Limitation of Local Richness (theoretical relationship), all figures contain data from real observations, as presented in Blake (1991, Patch Occupancy Frequency) and Gaston (1992; all others).