Figure 4.

Examples of spatial, temporal and spatio-temporal variation. The different shades of grey represent different densities of a population or values of an environmental variable. (a) Under pure spatial variation, factors vary across a spatial transect but are constant from one time period to another. (b) Under pure temporal variation, factors vary from one time to another but are constant across space. (c) Spatial and temporal variation can occur together; in this case, the factors change from one time to another but remain constant across space. (d) Under pure spatio-temporal variation, changes in factors with both space and time create a shifting mosaic.