Change in vegetation patterns over a large forested landscape based on historical and contemporary aerial photographyAuthor(s): Jamie M. Lydersen; Brandon M. Collins
Publication Series: Scientific Journal (JRNL)
Station: Pacific Southwest Research Station
Download Publication (2.0 MB)
Changes to vegetation structure and composition in forests adapted to frequent fire have been well documented. However, little is known about changes to the spatial characteristics of vegetation in these forests. Specifically, patch sizes and detailed information linking vegetation type to specific locations and growing conditions on the landscape are lacking. We used historical and recent aerial imagery to characterize historical vegetation patterns and assess contemporary change from those patterns. We created an orthorectified mosaic of aerial photographs from 1941 covering approximately 100,000 ha in the northern Sierra Nevada. The historical imagery, along with contemporary aerial imagery from 2005, was segmented into homogenous vegetation patches and classified into four relative cover classes using random forests analysis. A generalized linear mixed model was used to compare topographic associations of dense forest cover on the historical and contemporary landscapes. The amount of dense forest cover increased from 30 to 43% from 1941 to 2005, replacing moderate forest cover as the most dominant class. Concurrent with the increase in extent, the area-weighted mean patch size of dense forest cover increased tenfold, indicating greater continuity of dense forest cover and more homogenous vegetation patterns across the contemporary landscape. Historically, dense forest cover was rare on southwesterly aspects, but in the contemporary forest, it was common across a broad range of aspects. Despite the challenges of processing historical air photographs, the unique information they provide on landscape vegetation patterns makes them a valuable source of reference information for forests impacted by past management practices.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
CitationLydersen, Jamie M.; Collins, Brandon M. 2018. Change in vegetation patterns over a large forested landscape based on historical and contemporary aerial photography. Ecosystems. 348: 196. https://doi.org/10.1007/s10021-018-0225-5.
Keywordsimage object analysis, historical aerial photography, landscape restoration, vegetation change, landscape vegetation pattern, Sierra Nevada
- Historical and current forest landscapes of eastern Oregon and Washington Part I: Vegetation pattern and insect and disease hazards.
- Modeling change in potential landscape vulnerability to forest insect and pathogen disturbances: methods for forested subwatersheds sampled in the midscale interior Columbia River basin assessment.
- Change in extent of meadows and shrub fields in the central western cascade Range, Oregon
XML: View XML