Accession Number : ADP007198

Title :   Spatial Patterns of Trees Attacked by Beetles: Pseudolikelihood Estimation and Iterative Simulations,

Corporate Author : PACIFIC SOUTHWEST FOREST AND RANGE EXPERIMENT STATION BERKELEY CA

Personal Author(s) : Preisler, Haiganoush K.

Report Date : 1992

Pagination or Media Count : 4

Abstract : In this preliminary study a generalized linear model is used to describe the conditional probability of a tree being attacked by mountain pine beetles in a given year, given the characteristics of the tree (e.g., size) and the location of other attacked trees in the stand. The model is used to analyze mountain pine beetle attack data in two lodgepole pine stands in Oregon over a period of 10 years (see Fig. 1 and 2). The data may be viewed as a realization of a spatial point process with the probability of a tree being attacked dependent on the status of other trees in the stand. Although full maximum likelihood estimation is apparently not feasible, maximum pseudolikelihood estimates of the parameters can be readily calculated with standard statistical packages such as GLIM.

Descriptors :   *MAXIMUM LIKELIHOOD ESTIMATION, ATTACK, COLEOPTERA, ESTIMATES, MODELS, MOUNTAINS, OREGON, PARAMETERS, PROBABILITY, STANDARDS, TREES.

Subject Categories : Statistics and Probability

Distribution Statement : APPROVED FOR PUBLIC RELEASE