AN APPROACH FOR MANAGING VERTEBRATE DIVERSITY ACROSS MULTIPLE-USE LANDSCAPES

Land managers face the difficult challenge of maintaining biodiversity on lands also used for commodity production. We present an approach f or managing the habitats of terrestrial vertebrates at the landscape s cale on multiple-use lands. The approach is based on the hypothesis th at animal community response to landscape change is a function of spec ies life histories and local patterns of landscape change. Key steps a re: (1) set clear objectives; (2) associate target species with specif ic habitat configurations; (3) assess the potential sensitivity of spe cies by mapping habitat suitability and examining species life histori es; (4) evaluate alternative management prescriptions using simulation models; and (5) implement preferred or experimental strategies and mo nitor the responses of habitats and species. The approach was demonstr ated for a watershed in western Oregon. Management objectives were to maximize habitat diversity for early- and late-successional bird speci es and to produce saw timber at levels compatible with the habitat goa ls. Habitat associations of 51 bird species were described by four var iables that encompass three spatial scales. An analysis of species sen sitivity to landscape change revealed several species that may merit s pecial attention. The landscape model LSPA and the gap model ZELIG.PNW were used to simulate four disturbance/management scenarios over a 14 0-yr period: natural fire, wood production, multiple use, and no actio n. The results indicated that 65% more saw timber would be produced un der the wood production run than the multiple-use run, but the former would maintain habitats for many fewer bird species than the latter. T he multiple-use scenario was selected as the preferred alternative. We suggest carrying out management experiments and rigorous monitoring d uring the implementation phase. While this approach has various limita tions, it is an incremental step towards the effective management of s pecies diversity on multiple-use lands.