Edge, canopy and neighbourhood attributes as predictors of potential edge influence in boreal forests
(English)Manuscript (Other academic)
Forest edges play a key role in fragmented ecosystems and may strongly influence biodiversity. Edge influence is complex and site specific due to interactions among several local and regional factors. Data on these factors are crucial to predict potential edge influence. We assessed the variability in edge, canopy and neighbourhood attributes among 1008 sharp forest edges in northern Sweden. The edges represented three edge types: natural (wetland, water), maintained (e.g. roads, agriculture) and regenerating (clearcuts, young forest). Data was collected from 28 landscapes (each 1600 ha) using line intersect sampling and stereo interpretation of colour infrared aerial photographs in a digital photogrammetric system. Due to the topography, natural edges were predominantly oriented towards SW or NE while created edges had a more uniform pattern. Created edges had denser canopies and higher contrast in tree height than natural edges. Regenerating edges had the largest fetch, followed by natural and maintained edges. The regenerating edges thus experience the highest risk of wind damage. The majority of edges in mature productive conifer forest had high contrast and large fetch. Overall, edges showed high variability with respect to potential for microclimatic edge influence. This suggests that biodiversity in boreal forests may have a broad range of responses to edges. Our analysis shows that predictions of edge influence on biodiversity in forest ecosystems can be improved by combining edge, canopy and neighbourhood attributes.
aerial photographs, edge contrast, edge orientation, fetch size, forest fragmentation
Research subject Ecological Botany
IdentifiersURN: urn:nbn:se:umu:diva-21662OAI: oai:DiVA.org:umu-21662DiVA: diva2:211435