Growth and Ecology of Rhizocarpon Section Rhizocarpon on Mount Kenya, East Africa

Abstract

Environmental factors that may influence colonization, establishment, and growth of Rhizocarpon section Rhizocarpon species were studied in the Tyndall Cirque on Mount Kenya, East Africa. Analysis of variance and pairwise t-tests indicate that neither substrate orientation (aspect) nor inclination (slope angle) appear to influence lichen performance during the first 100 yr of colonization and growth. Growth during this (great-growth) period appears to increase in a linear fashion. After an initial period of variability, the ratio of mean thallus to largest thallus increases to a stable value. The suggestion is made that the early variability is the result of intermittent colonization and establishment events.