Canadian Forest Service Publications
Prevalence of multiple forest disturbances and impact on vegetation regrowth from interannual Landsat time series (1985–2015). 2019. Hermosilla, T., Wulder, M.A., White, J.C., Coops, N.C. Remote Sensing of Environment, 233, 111403.
Issued by: Pacific Forestry Centre
Catalog ID: 40018
Availability: PDF (download)
Available from the Journal's Web site. †
† This site may require a fee
Given long time series of satellite imagery, multiple disturbances can be detected for a particular location at different points in time. We assessed multiple disturbances for the 650 Mha of Canada's forested ecosystems using annual change information derived from Landsat time series imagery (1985–2015). Changes were typed by agent (fire, harvest, and non-stand replacing). Spectral change rate and time between successive disturbances were used to characterize disturbance-type combination differences. Short-term spectral recovery following the last disturbance was compared to a reference sample of pixels disturbed only once. Results indicated that of the 97.6 Mha disturbed, 13.5 Mha have had two or more disturbances, with low magnitude non-stand replacing disturbances involved in the majority of occurrences (77.2%). The total area disturbed represents 18.27% of forest ecosystems, with 2.53% having multiple disturbances and 0.54% having multiple stand-replacing disturbances. Systematic time series-based investigation of multiple disturbance events and agents provides insights on forest disturbance dynamics and recovery processes.
Plain Language Summary
Multiple disturbances which overlap through time may alter the successional development pathways. The objective of this research is an improved understanding of the frequency and nature of multiple disturbance dynamics for Canada’s forested ecosystems. Using Landsat time series imagery and derived forest change products we analyzed the frequency, distribution and agents of multiple forest disturbances, and related short-term vegetation recovery, for the period 1985-2015. Both stand replacing and non-stand replacing disturbances are included in the analysis. Systematic analysis of multiple disturbances using dense time series of remotely sensed imagery informs on both forest disturbance dynamics and recovery processes. The results indicated that for the analyzed period, 18.27% of Canada’s forested ecosystems (excluding waterbodies) underwent disturbances, and 2.53% was impacted by multiple disturbances (two or more disturbance events). While wildfires are the principal stand-replacing disturbance agent by area in Canada’s forests, the majority of multiple disturbances involved non-stand replacing events. This information is valuable to advise planning activities for sustainable forest management and to inform expectations of future carbon stocks.