Appendix B. A figure demonstrating Whittaker's topographic moisture gradient (TMG).
FIG. B1. Examples of species distributions along Whittaker’s topographic moisture gradient (TMG), from mesic (cool north-facing) to xeric (warm south-facing) sites. The relationship between the TMG and the number of individuals per plot for representative tree species in 1950 is shown. Port Orford cedar (Cupressus lawsoniana) is a mesic (cool-site-associated) tree species on both soils. Tanoak (Lithocarpus densiflorus) and whiteleaf manzanita (Arctostaphylos viscida) are xeric (warm-site-associated) species found on diorite and serpentine soils, respectively. |