Skip to main content
Advanced Search

Filters: Types: Shapefile (X) > Types: OGC WFS Layer (X) > Extensions: Citation (X) > Categories: Publication (X) > partyWithName: Wulder, Michael A. (X)

27 results (10ms)   

View Results as: JSON ATOM CSV
thumbnail
The recovery of forests following stand-replacing disturbance is of widespread interest; however, there is both a lack of definitional clarity for the term “recovery” and a dearth of empirical data on the rates of forest recovery associated with different disturbance types. We conducted a quantitative review of literature to determine recovery times following wildfire and timber harvest and to evaluate variation in recovery rates across Canada’s diverse forest ecosystems. Recovery was assessed according to the rate of change associated with certain forest structural attributes that have traditionally been used as indicators of forest growth and productivity. The recovery of forest canopy cover, tree height, and...
thumbnail
Post-fire regrowth is an important component of carbon dynamics in Canada's boreal forests, yet observations of structural development following fire are lacking across this remote and expansive region. Here, we used Landsat time-series data (1985–2010) to detect high-severity fires in the Boreal Shield West ecozone of Canada, and assessed post-fire structure for > 600 burned patches (> 13,000 ha) using airborne light detection and ranging (lidar) data acquired in 2010. We stratified burned areas into patches of dense (> 50% canopy cover) and open (20–50% canopy cover) forests based on a classification of pre-fire Landsat imagery, and used these patches to establish a 25-year chronosequence of structural development...
thumbnail
Utilizing the spatial information inherent in panchromatic very high spatial resolution (VHSR) imagery, we explored the use of tree crown metrics for identifying leading species over four study sites in the Yukon Territory, Canada. Image segmentation was used to delineate homogeneous forest stands, followed by a tree crown delineation algorithm that identified individual tree crowns within each stand. Leading species in the study area included white spruce, black spruce, lodgepole pine, and trembling aspen. Nonparametric multivariate statistical tests indicated that some tree crown metrics generalized at the stand level have significant utility for discriminating leading species. Based on this result, a classification...
thumbnail
ABSTRACTA critical component of landscape dynamics is the recovery of vegetation following disturbance. The objective of this research was to characterize the forest recovery trends associated with a range of spectral indicators and report their observed performance and identified limitations. Forest disturbances were mapped for a random sample of three major bioclimate zones of North American boreal forests. The mean number of years for forest to recover, defined as time required to for a pixel to attain 80% of the mean spectral value of the 2 years prior to disturbance, was estimated for each disturbed pixel. The majority of disturbed pixels recovered within the first 5 years regardless of the index ranging from...
thumbnail
Forests are an important global resource, playing key roles in both the environment and the economy. The implementation of quality national monitoring programs is required for the generation of robust national statistics, which in turn support global reporting. Conventional monitoring initiatives based on samples of field plots have proven robust but are difficult and costly to implement and maintain, especially for large jurisdictions or where access is difficult. To address this problem, air photo- and satellite-based large area mapping and monitoring programs have been developed; however, these programs also require ground measurements for calibration and validation. To mitigate this need for ground plot data...
thumbnail
Canada is dominated by remote wilderness areas that make important conservation contributions, but are currently only protected de facto by their inaccessibility. Mechanisms for the identification and formal protection of such areas can help ensure that they continue to function naturally and provide essential ecosystem services. However, a lack of spatially explicit, publicly available sources of data on anthropogenic disturbances and natural resource extraction challenges the development of detailed wilderness inventories. We suggest that landscape structure can be used to classify areas of natural landscapes, as trained by the landscape structure of protected areas, and demonstrate this approach by mapping de...
thumbnail
The objective of this study is to provide an approach for assessing the short-term risk of mountain pine beetle Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae) attack over large forested areas based on the spatial-temporal behavior of beetle spread. This is accomplished by integrating GIS, aerial overview surveys, and local indicators of spatial association (LISA) in order to measure the spatial relationships of mountain pine beetle impacts from one year to the next. Specifically, we implement a LISA method called the bivariate local Moran's Ii to estimate the risk of mountain pine beetle attack across the pine distribution of British Columbia, Canada. The bivariate local Moran's Ii provides a means for...
thumbnail
Characterizing the amount and configuration of forests can provide insights into habitat quality, biodiversity, and land use. The establishment of protected areas can be a mechanism for maintaining large, contiguous areas of forests, and the loss and fragmentation of forest habitat is a potential threat to Canada's national park system. Using the Earth Observation for Sustainable Development of Forests (EOSD) land cover product (EOSD LC 2000), we characterize the circa 2000 forest patterns in 26 of Canada's national parks and compare these to forest patterns in the ecological units surrounding these parks, referred to as the greater park ecosystem (GPE). Five landscape pattern metrics were analyzed: number of forest...
map background search result map search result map Identifying leading species using tree crown metrics derived from very high spatial resolution imagery in a boreal forest environment Identification of de facto protected areas in boreal Canada Characterizing residual structure and forest recovery following high-severity fire in the western boreal of Canada using Landsat time-series and airborne lidar data Modelling the ecosystem indicators of British Columbia using Earth observation data and terrain indices Forest recovery trends derived from Landsat time series for North American boreal forests Combining satellite lidar, airborne lidar, and ground plots to estimate the amount and distribution of aboveground biomass in the boreal forest of North America Measuring forest structure along productivity gradients in the Canadian boreal with small-footprint Lidar Characterizing the forest fragmentation of Canada's national parks Fragmentation regimes of Canada's forests A remote sensing approach to biodiversity assessment and regionalization of the Canadian boreal forest Multitemporal remote sensing of landscape dynamics and pattern change: describing natural and anthropogenic trends Exploring the ecological processes driving geographical patterns of breeding bird richness in British Columbia, Canada Predicting Climate Change Impacts to the Canadian Boreal Forest Modeling lodgepole and jack pine vulnerability to mountain pine beetle expansion into the western Canadian boreal forest A GIS-based risk rating of forest insect outbreaks using aerial overview surveys and the local Moran's I statistic Trends in post-disturbance recovery rates of Canada’s forests following wildfire and harvest Lidar plots -- a new large-area data collection option: context, concepts, and case study Assessing variability in post-fire forest structure along gradients of productivity in the Canadian boreal using multi-source remote sensing Evaluating Natural Reserve Design Efficacy in the Canadian Boreal Forest Using Time Series AVHRR Data Forest recovery trends derived from Landsat time series for North American boreal forests Characterizing the forest fragmentation of Canada's national parks Identifying leading species using tree crown metrics derived from very high spatial resolution imagery in a boreal forest environment Multitemporal remote sensing of landscape dynamics and pattern change: describing natural and anthropogenic trends Exploring the ecological processes driving geographical patterns of breeding bird richness in British Columbia, Canada Modelling the ecosystem indicators of British Columbia using Earth observation data and terrain indices Modeling lodgepole and jack pine vulnerability to mountain pine beetle expansion into the western Canadian boreal forest A GIS-based risk rating of forest insect outbreaks using aerial overview surveys and the local Moran's I statistic Characterizing residual structure and forest recovery following high-severity fire in the western boreal of Canada using Landsat time-series and airborne lidar data Forest recovery trends derived from Landsat time series for North American boreal forests Combining satellite lidar, airborne lidar, and ground plots to estimate the amount and distribution of aboveground biomass in the boreal forest of North America Forest recovery trends derived from Landsat time series for North American boreal forests Trends in post-disturbance recovery rates of Canada’s forests following wildfire and harvest Identification of de facto protected areas in boreal Canada A remote sensing approach to biodiversity assessment and regionalization of the Canadian boreal forest Fragmentation regimes of Canada's forests Predicting Climate Change Impacts to the Canadian Boreal Forest Measuring forest structure along productivity gradients in the Canadian boreal with small-footprint Lidar Lidar plots -- a new large-area data collection option: context, concepts, and case study Assessing variability in post-fire forest structure along gradients of productivity in the Canadian boreal using multi-source remote sensing Evaluating Natural Reserve Design Efficacy in the Canadian Boreal Forest Using Time Series AVHRR Data