Perception of scale in forest management planning: Challenges and implications

Abstract

Forest management practices imposed at one spatial scale may affect the patterns and processes of ecosystems at other scales. These impacts and feedbacks on the functioning of ecosystems across spatial scales are not well understood. We examined the effects of silvicultural manipulations simulated at two spatial scales of management planning on landscape 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 planning activities was at the level of individual stands and the context in which stands were located was not considered). We also compared ecological implications of patterns created at the stand and landscape levels by even- and uneven-age silvicultural systems. We used a harvest simulator (HARVEST) to simulate even-age, uneven-age and a combination of even- and uneven-age management systems for a period of 5 decades in the two forest management planning scenarios. Clearcuts of 5 to 16 ha were simulated to represent even-age management and small openings of 0.09 to 0.22 ha scattered throughout a stand were simulated to represent uneven-age management. Forest management that considered landscape context generated greater landscape total core area compared to that of the stand-base planning. There was a difference in landscape mean patch size, interspersion index, Simpson's diversity index and total core area for patches defined by stand age between stand- and landscape-base management planning. These results indicate that different landscape patterns can be produced by management planning conducted at different spatial scales. The scale of focus should depend on the management goals. Silvicultural manipulations at the stand level can cause the creation of different patterns at the stand and landscape levels. Such differences can lead to different ecological implications at each of those 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 effects depend on how patches are defined.