A5018515719- Plant Water Relations and Carbon Dynamics
- Tree-ring climate responses
- Forest ecology and management
- Fire effects on ecosystems
- Ecology and Vegetation Dynamics Studies
- Peatlands and Wetlands Ecology
- Forest Management and Policy
- Coastal wetland ecosystem dynamics
- Botany and Plant Ecology Studies
- Remote Sensing and LiDAR Applications
- Climate change and permafrost
- Rangeland and Wildlife Management
- Botany, Ecology, and Taxonomy Studies
- Remote Sensing in Agriculture
- Climate variability and models
- Hydrology and Sediment Transport Processes
- Bioenergy crop production and management
- Forest Insect Ecology and Management
- Plant responses to elevated CO2
- Forest Ecology and Biodiversity Studies
- Pasture and Agricultural Systems
- Marine and coastal plant biology
- Australian Indigenous Culture and History
- Environmental Conservation and Management
- Algal biology and biofuel production
Natural Resources Canada
2011-2022
Canadian Forest Service
2010-2022
University of Alberta
1991-2008
Alberta Environment and Protected Areas
2008
Lund University
1994
Harvard University
1993
Parks Canada
1993
Kootenay National Park
1993
Forestry Research Centre
1993
Canadian boreal woodlands and forests cover approximately 3.09 × 10 6 km 2 , located within a larger zone characterized by cool summers long cold winters. Warming since the 1850s, increases in annual mean temperature of at least °C between 2000 2050 are highly probable. Annual temperatures across could be 4–5 warmer than today’s 2100. All aspects forest ecosystem function likely to affected. Further, several potential “tipping elements” — where exposure increasing changes climate may trigger...
Forest insects and pathogens are major disturbance agents that have affected millions of hectares in North America recent decades, implying significant impacts to the carbon (C) cycle. Here, we review synthesize published studies effects biotic disturbances on forest C cycling United States Canada. Primary productivity stands was reduced, sometimes considerably, immediately following insect or pathogen attack. After repeated growth reductions caused by some a single infestation bark beetle...
Drought-induced, regional-scale dieback of forests has emerged as a global concern that is expected to escalate under model projections climate change. Since 2000, drought unusual severity, extent, and duration affected large areas western North America, leading in the southwestern US. We report on impacts region farther north, encompassing transition between boreal forest prairie Canada. A central question significance an agent large-scale tree mortality its potential future impact carbon...
We examined the impacts of a severe, regional drought (2001–2002) on trembling aspen ( Populus tremuloides Michx.) forests in western Canadian interior. A total 150 plots were established 25 study areas as part regional-scale (CIPHA). Aspen health and mortality assessed annually during 2000–2005, changes stem biomass estimated using tree-ring analysis plot-based measurements. Net mean increment living for all was 2.2 t·ha –1 ·year 2000–2002 but subsequently decreased to near zero. This...
Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, long-term impacts of rising and associated shifts in hydrological cycle on productivity ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability terrestrial aboveground biomass stem growth across Canada's boreal forests from 1950 present. We use 873 newly developed tree-ring chronologies...
A boreal deciduous forest in Saskatchewan, Canada, sequestered 144±65, 80±60, 116±35 and 290±50 g C m −2 y −1 1994, 1996, 1997 1998, respectively. The increased carbon sequestration was the result of a warmer spring earlier leaf emergence, which significantly ecosystem photosynthesis, but had little effect on respiration. high 1998 coincident with one strongest El Niño events this century, is considered significant unexpected benefit.
Trembling aspen (Populus tremuloides Michx.) is the most important deciduous tree in Canadian boreal forest, with >1000 Tg of carbon stored aboveground biomass this species. Since early 1990s, dieback has been noted over parts southern forest and parkland western Canada. In study, tree-ring analysis health assessments were conducted 18 stands near Grande Prairie, Alta., to examine causes reduced growth dieback. Defoliation histories reconstructed based on light-colored ("white") rings...
Abstract The carbon and water budgets of boreal temperate broadleaf forests are sensitive to interannual climatic variability likely respond climate change. This study analyses 9 years eddy‐covariance data from the Boreal Ecosystem Research Monitoring Sites (BERMS) Southern Old Aspen site in central Saskatchewan, Canada characterizes primary controls on evapotranspiration, net ecosystem production ( F NEP ), gross photosynthesis P ) respiration R ). period was dominated by two extremes:...
Four species of boreal forest conifers share a similar southern limit natural distribution in the three Prairie Provinces western Canada. The boundaries and aspen parkland were compared with geographic patterns several climate variables to provide preliminary assessment how global change could affect future. Forest zonation corresponded most closely climatic moisture regimes (annual precipitation minus potential evaporation). In contrast, thermal characteristics (mean July annual...
Global warming and the resultant increase in evapotranspiration might lead to lowered water tables peatlands an fire frequency. The objective of this study was investigate some potential effects these changes on peat decomposition. Dry mass losses emissions CO 2 CH 4 from samples taken three depth layers (0—10, 10—20, 30—40 cm) a black spruce peatland were measured laboratory at 8°, 16°, 24°C under two moisture treatments. Effects deep decomposition also simulated by burning upper layer...
Sudden dieback and deterioration of mature aspen stands is commonly observed throughout North America. This process has tremendous ecological economic importance, yet remains poorly understood. paper summarizes our understanding in America, identifies potential processes that contribute to reduced vigour stands, examines the scales (stand, ecosite, regional) at which these operate. Many factors including pathogens, nutrition, or successional changes may be involved decline thereby process....
We monitored sap flow and estimated diurnal changes in transpiration rates of two trembling aspen (Populus tremuloides Michx.) stands, located the southern boreal forest parkland Saskatchewan, Canada. In both stands during peak growing season (June July), day (0700–1700 h local time) increased linearly with vapor pressure deficit (VPD) from 0 to about 1 kPa, but then remained remarkably constant at VPD > kPa (up 4.8 stand). The results imply an inverse relationship between stomatal...
Trembling aspen (Populus tremuloides Michx.) is the most important deciduous tree in North American boreal forest and also dominant parkland zone along northern edge of Canadian prairies. Since 1990s, observations dieback reduced growth forests have led to concerns about potential impacts climate change. To address these concerns, a regional-scale study (CIPHA) was established 2000 that includes annual monitoring health productivity 72 stands across western interior. Tree-ring analysis...
Abstract An increasing number of studies conclude that water limitations and heat stress may hinder the capacity black spruce ( Picea mariana (Mill.) B.S.P.) trees, a dominant species Canada's boreal forests, to grow assimilate atmospheric carbon. However, there is currently no scientific consensus on future these forests over next century in context widespread climate warming. The large spatial extent across Canadian forest associated variability climate, demography, site conditions pose...
Quantitative assessment of Canada’s boreal forest mitigation potential is not yet possible, though the range activities known, requirements for sound analyses options are increasingly understood, and there emerging recognition that biogeophysical effects need greater attention. Use a systems perspective highlights trade-offs between aimed at increasing carbon storage in ecosystem, harvested wood products (HWPs), or substitution benefits using place fossil fuels more emissions-intensive...
Since 2001, climatic conditions have been notably drier than normal across large areas of the western Canadian interior, leading to widespread impacts on forests this region. This poses a major concern for future, given climate change projections continued warming and drying. We conducted tree-ring analysis in 75 pure stands white spruce (Picea glauca) Alberta west-central Saskatchewan examine effects recent drying growth important boreal tree species. Allometric equations were used...
Tree ring studies have shown that drought is a major factor governing growth of aspen (Populus tremuloides Michx.) forests in western Canada. Previous analyses showed interannual variation radial moderately well-correlated with climate moisture index (CMI), calculated annually as the difference between precipitation (P) and potential evapotranspiration (PE). However, there are multi-year lags, where current year significantly related to CMI over each preceding 5 years. We postulated such...
Abstract Increasing tree mortality from global change drivers such as drought and biotic infestations is a widespread phenomenon, including in the boreal zone where climate changes feedbacks to Earth system are relatively large. Despite importance for science management communities, our ability forecast at landscape continental scales limited. However, two independent information streams have potential inform improve forecasts: repeat forest inventories satellite remote sensing. Time series...
Abstract Projected changes in climate conditions vary widely across Canada's 350 M ha of forests, and so does the capacity forest species to cope with these (sensitivity). Development prioritization adaptation strategies for sustainable management will depend on integrated assessments relative stand vulnerability. We developed species‐specific indices sensitivity (1) drought‐induced mortality (2) migration failure, based traits 22 most abundant tree Canada. By combining this information...