PERCEPTION OF SCALE IN FOREST MANAGEMENT PLANNING - CHALLENGES AND IMPLICATIONS

Forest management practices imposed at one spatial scale may affect th e patterns and processes of ecosystems at other scales. These impacts and feedbacks on the functioning of ecosystems across spatial scales a re not well understood. We examined the effects of silvicultural manip ulations simulated at two spatial scales of management planning on lan dscape pattern and assessed the implications for forest-interior bird species. Landscape context was taken into consideration in determining harvest locations in the landscape-base management planning scenario but not in the stand-base planning scenario (where the focus of planni ng activities was at the level of individual stands and the context in which stands were located was not considered). We also compared ecolo gical implications of patterns created at the stand and landscape leve ls by even-and uneven-age silvicultural systems. We used a harvest sim ulator (HARVEST) to simulate even-age, uneven-age and a combination of even-and uneven-age management systems for a period of 5 decades in t he two forest management planning scenarios. Clearcuts of 5 to 16 ha w ere simulated to represent even-age management and small openings of 0 .09 to 0.22 ha scattered throughout a stand were simulated to represen t uneven-age management. Forest management that considered landscape c ontext generated greater landscape total core area compared to that of the stand-base planning. There was a difference in landscape mean pat ch size, interspersion index, Simpson's diversity index and total core area for patches defined by stand age between stand-and landscape-bas e management planning. These results indicate that different landscape patterns can be produced by management planning conducted at differen t spatial scales. The scale of focus should depend on the management g oals. Silvicultural manipulations at the stand level can cause the cre ation of different patterns at the stand and landscape levels. Such di fferences can lead to different ecological implications at each of tho se levels, thereby making it difficult to simply aggregate stand-level responses to the landscape-level. Furthermore, the ecological effects of landscape patterns on processes can be highly variable as the effe cts depend on how patches are defined. (C) 1997 Elsevier Science B.V.