Reconstruction of Piñon-Juniper Forest Structure to Examine Historic Wildlife Habitat Characteristics in the Davis Mountains, USA

Abstract

Changes in pinon-juniper (Pinus spp., Juniperusspp.) communities across the southwestern United States have often decreased ecological diversity of the understory and increases of exotic species. Reconstructing age and establishment patterns provides essential understanding to guide treatments and management for anthropogenically-altered forests. The goal of this study was to determine how patterns of pinon and juniper growth in the Davis Mountains, Texas, varied over time and how this pattern influenced wildlife habitat of several indicator species. Establishment patterns and basal area growth progression were identified, canopy cover estimates regressed from pre-developed canopy regression equations to re-construct historic forest stand structure and canopy characteristics in twenty-year intervals and applied to known wildlife habitat requirements of Montezuma quail (Cyrtonyx montezumae), black bear (Ursus americanus) and White-tailed deer/Mule deer (Odocoileus virginianus/O. hemionus). The sites provided habitat for these wildlife species, but the specific habitat provided changed over time. Prescribed burning could promote better forage for black bear while fire exclusion could improve dense cover for escape and denning cover. Montezuma quail would use thinner, less-dense habitats for forage, loafing and escape cover and the denser stand dynamics for cover and shelter. If forage habitat for Montezuma quail is required, the more open habitats found in the early 1900’s could be re-established by prescribed burning and tree removal. Habitat for White-tailed deer transitioned from more open forage, loafing, fawning cover in the early 1900’s to denser thermal, and escape cover in the later 1900’s. Mule deer habitat transitioned from a preferred open habitat to a more dense cover habitat that would be utilized primarily for bedding. Prescribed burning and tree removal to open up the current habitat would benefit Mule deer and white-tailed deer to a lesser degree.