2000

Brian David Purcell, A comparitive Study of the Biases and Efficiencies of Tree Density Estimators Using Variable Plot Fixed Plot Sampling in Uneven Aged Stands

Abstract: This thesis examines the biases and efficiencies of tree density estimators using two types of forest sampling, variable and fixed plot sampling. This was accomplished by simulating a forest and sampling it using both methods. The forest was simulated to be uneven aged, with both random and clustered spacing. The program was written by the author using Microsoft Visual Basic 6.0. To evaluate the accuracy of the forest sampling estimators, the author first examined the biases and efficiencies of basal area per acre estimators using variable and fixed plot sampling. Because it is well established that variable plot sampling is more efficient in estimating basal area than fixed plot sampling, the program should and did show results that are consistent with comparisons made on actual forests. For density estimation, however, the results demonstrated that variable plot sampling in not as efficient as fixed plot sampling.