Plant Indicator Species
Many site properties such as available water and nutrient concentrations are not easily measured, so an alternative is to measure indicative variables such as composition of ground vegetation. No causal relationship is implied, but it is assumed that both ground vegetation and timber production are influenced by the same properties (Vanclay, 1992). The accuracy of any attempt to model forest systems depends largely upon the precision with which the site can be classified into homogeneous units (Gertner and Dzialowy, 1984; Smith and Burkhart, 1984).