A5062325937- Forest ecology and management
- Plant Water Relations and Carbon Dynamics
- Fire effects on ecosystems
- Forest Ecology and Biodiversity Studies
- Tree-ring climate responses
- Ecology and Vegetation Dynamics Studies
- Forest Management and Policy
- Seedling growth and survival studies
- Remote Sensing and LiDAR Applications
- Tree Root and Stability Studies
- Bioenergy crop production and management
- Remote Sensing in Agriculture
- Botany and Plant Ecology Studies
- Rangeland and Wildlife Management
- Peatlands and Wetlands Ecology
- Fish Ecology and Management Studies
- Marine and fisheries research
- Forest Biomass Utilization and Management
- Forest Insect Ecology and Management
- Hydrology and Watershed Management Studies
- Soil Geostatistics and Mapping
- Weed Control and Herbicide Applications
- Coral and Marine Ecosystems Studies
- Lichen and fungal ecology
- Wood Treatment and Properties
University of Alberta
2016-2025
Fisheries and Oceans Canada
2013-2024
Bedford Institute of Oceanography
2013-2024
Government of British Columbia
1990-2011
Ontario Forest Research Institute
2010
Ministry of Natural Resources and Forestry
2010
Canadian Forest Service
2008-2010
Université du Québec à Montréal
1999-2006
Kamloops Art Gallery
2002
University of British Columbia
1986
This paper reviews current information relating to the dynamics of light in northern and boreal forests discusses factors affecting overstory transmission, seasonality light, sunflecks, canopy gaps, understory development, particularly with regard tree regeneration. Techniques for measurement such as radiometers, photosensitive or chemicals, hemispherical photographs, plant analyzer, visual estimators density are each discussed terms their accuracy, costs, ease use, conditions required...
Aspen (Populus tremuloides Michx.) is a clonal tree species that commonly regenerates via root suckering after disturbance. This paper reviews the literature and identifies critical gaps in our understanding of dynamics aspen suckering. The role plant growth regulators (e.g., hormones, carbohydrates), environmental conditions soil moisture, temperature, nutrient availability), overstory disturbance harvesting, wildfire), ground compaction, wounding or severing roots), vegetation competition,...
The distribution of tree biomass and the allocation production was measured in four stands lodgepole pine (Pinuscontorta var. latifolia Engelm.), two growing on sites with xeric soil moisture regimes mesic regimes. At time sampling were 70–78 years old. Aboveground ranged from 116.5 Mg•ha −1 one site to 313.1 site. Stem represented 68 73% total sites, respectively. Total root between 20 28% biomass. Fine small roots (<5 mm diameter) 4 1.5% net primary 7.9 •year 11.9 sites. Stemwood 27%...
Despite great concern for drought-driven forest mortality, the effects of frequent low-intensity droughts have been largely overlooked in boreal because their negligible impacts over short term. In this study, we used data from 6876 permanent plots distributed across most Canadian zone to assess repeated on mortality. Specifically, compared relative impact sequential years under dry conditions with variables related intensity conditions, stand characteristics, and local climate. Then,...
The effects of gradients in light levels and tree height on growth crown attributes six conifer species were studied eastern western Canada. Three conifers British Columbia (Abies lasiocarpa (Hook.) Nutt., Picea glauca (Moench) Voss × engelmannii Parry ex Engelm., Pinus contorta Dougl. Loud. var. latifolia Engelm.), three Quebec balsamea (L.) Mill., glauca, banksiana Lamb.). For several morphological parameters, reacted strongly to both an increase height. Significant or nearly significant...
Abstract Adequate and advance knowledge of the response forest ecosystems to temperature‐induced drought is critical for a comprehensive understanding impacts global climate change on ecosystem structure function. Recent massive decline in aspen‐dominated forests an increased aspen mortality boreal have been associated with warming, but it still uncertain whether are driven by drought. We used series ring‐width chronologies from 40 trembling ( Populus tremuloides Michx.) sites along...
Abstract Insects, diseases, fire and drought other disturbances associated with global climate change contribute to forest decline mortality in many parts of the world. Forest related or insect outbreaks have been observed North American aspen forests. However, little research has done partition estimate their relative contributions growth declines. In this study, we combined tree‐ring width basal area increment series from 40 trembling ( Populus tremuloides Michx.) sites along a latitudinal...
In 1996 we initiated a study to evaluate several techniques for measuring light under broadleaf canopies. Hourly average photosynthetic photon flux density and percent transmittance were measured 1 m above the ground at four points in each of three canopy densities created by spacing experiment 35-year-old paper birch (Betula papyrifera Marsh.) dominated stand located near Prince George, B.C. At point, fisheye photographs taken LAI-2000 plant analyzer (LAI-2000), spherical densiometer,...
To examine the effects of overtopping vegetation on solar irradiance reaching Engelmann spruce (Piceaengelmannii Parry) seedlings and crop seedling performance, neighborhood studies were established at six sites in mixed shrub–herb fireweed communities Interior Cedar–Hemlock zone southern British Columbia. These dominated by mixtures (Epilobiumangustifolium L.), thimbleberry (Rubusparviflorus Nutt.), red raspberry (Rubusidaeus (or) bracken fern (Pteridiumaquilinum (L.) Kuhn). Three hundred...
We evaluated the Mixedwood Growth Model (MGM) at a whole model scale for pure and mixed species stands of aspen white spruce in western boreal forest. MGM is an individual tree-based, distance-independent growth model, designed to evaluate yield implications relating management spruce, black aspen, lodgepole pine, mixedwood Alberta, British Columbia, Saskatchewan, Manitoba. Our validation compared stand-level predictions against re-measured data (volume, basal area, diameter breast height...
We examined the effect of competition on stem growth Picea glauca and Populus tremuloides in boreal mixedwood stands during exclusion stage. combined traditional approaches collecting data with dendrochronology to provide retrospective measurements diameter growth. Several indices including stand basal area (BA), sum at breast height (SDBH), density (N) for broadleaf coniferous species, as well similar considering only trees diameters greater than each subject (BAGR, SDBHGR, NGR), were...
We describe a range of approaches for managing boreal mixedwood stands composed trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) in British Columbia Alberta. Successful management these complex forests requires combination well-defined objectives at the landscape level flexible planning stand level. A variety strategies must be applied concurrently across to ensure that natural mix forest types structural diversity is maintained. Selected are...
The effectiveness of competition indices for predicting light transmittance and white spruce ( Picea glauca (Moench) Voss) growth were examined across trembling aspen Populus tremuloides Michx.) density gradients using sites from a long-term study mixedwood development in Alberta Saskatchewan. Competition based on (number trees, basal area, spacing factor), distance-dependent -independent size ratio (Hegyi’s Lorimer’s), crown characteristics (crown volume, surface cross-sectional area)...
Stockpiling of cover soil can influence vegetation development following reclamation. Cover soil, comprising the upper 15–30 cm surface material on sites scheduled for mining, is commonly salvaged prior to mining and used directly or stockpiled various lengths time until it needed. Salvaging stockpiling causes physical, chemical, biological changes in soils. In particular, reduces availability vigor vegetative propagules seed, lead increases abundance some weedy species. This study uses data...
Understanding the effects of reclamation treatments on plant community development is an important step in setting realistic indicators and targets for upland oil sands sites to forest ecosystems. We examine trends cover, richness, evenness, composition four cover soil types (clay over overburden, clay tailings sand, peat‐mineral mix sand) natural boreal forests a 20 year period mineable region northern Alberta, Canada. Tree, shrub, nonvascular species showed similar increases time all...