Ten-Year Risk-Rating Systems for California Red Fir and White Fir: Development and Use

摘要

Logistic regression equations predicting the probability that a tree will die from natural causes--insects, diseases, intertree competition--within 10 years have been developed for California red fir (Abies magnifica) and white fir (A.concolor). The resulting Risk Point Total is related to the percentage of a hypothetical population of identical trees expected to die within 10 years. Three risk classes (low, medium, and high) are defined and depicted for rapid visual estimation of risk in application where a more precise estimate is not required.