TESTS OF WILDLIFE HABITAT MODELS TO EVALUATE OAK-MAST PRODUCTION

We measured oak-mast production and forest structure and composition i n the Ozark Mountains of Missouri and tested the accuracy of oak-mast prediction variables from 5 Habitat Suitability Index (HSI) species mo dels. Acorn production was positively associated with several measures of abundance and canopy cover of oak trees, and with an index of mast production for all 5 HSI models. We developed 2 modified oak-mast mod els, based on inputs related to either oak tree density or oak canopy cover and diversity of oak tree species, The revised models accounted for 22-32% of the variance associated with acorn abundance. Future tes ts of HSI models should consider: (1) the concept of upper limits impo sed by habitat and the effects of nonhabitat factors; (2) the benefits of a top-down approach to model development; and (3) testing models a cross broad geographic regions.