bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of pre-European settlement forest characterization methodologies
Authors: Betts Matthew , Loo Judy
Published: February 2014

The characterization of "natural" or "presettlement" forest has become a relatively common practice in Canada as forest managers strive to put into practice concepts of sustainable forest management. Various methods have been developed to undertake such characterizations, leading to confusion about how to define "presettlement forest" and uncertainty over the approach that will best serve as a basis for management. We report on two methods of presettlement forest characterization: the "Witness Tree" and the "Potential Forests" approaches. We compare results from these approaches to the existing forest composition in the Fundy Model Forest, New Brunswick. Both approaches indicate a decline in the predominance of tolerant hardwood and eastern cedar since presettlement. However, the Potential Forests approach consistently suggests much higher presettlement frequencies of spruce (Picea spp.) and, in most cases, pine (Pinus spp.) than the Witness Tree method. Differences between frequencies of tree species estimated by the two methods probably result from biases associated with both methods and the different scales of reporting. If used critically, the combined use of both sets of presettlement forest information will allow managers to determine the historical frequency of individual tree species and forest communities. Such information will provide some guidance in maintaining the diversity of native species and community types. Key words: presettlement forest, ecological land classification, Witness Tree method, Potential Forests, forest management, biodiversity
No easy answers: Research and innovation for the forestry sector
Authors: Wright Joseph D
Published: February 2014

The Canadian Forest Sector is at a crossroads. Compared with its best global competitors, the sector's returns have been low. Its propensity to operate at the commodity end of the spectrum, coupled with an intense focus on cost cutting, has raised serious questions as to the long-term viability of research and technology as part of an innovation process. Stated provocatively, the question is "Does this sector need research? Why? For what?" And yet the evidence is clear. For sustainable growth and healthy balance sheets, more attention is needed on initiatives to add value, to move up the value chain, and to benefit from a more strategic focus on proprietary technological advantage. Too much reliance on suppliers, alone, for technology cannot yield sustainable leadership through innovation. Appropriate partnerships with technology providers ranging from universities, research institutes and suppliers, coupled with an in-house focus on innovative new products can lead to marketplace competitiveness. To balance needed industry investments, appropriate participation from governments at all levels can ensure that public policy-driven technology change can achieve societal goals in concert with achieving and maintaining industry competitiveness. Research institutes are key partners here with their focus on translating science into technology applied at the mill level. An environment that will attract highly qualified personnel into a sector often seen as less exciting than others more visibly tied to the information age will only occur when industry is seen to be highly supportive of innovation as a competitive force. The challenges are great but the potential returns are far higher if industry and government join forces to foster a truly innovative forest sector. Key words: research and development, innovation, research institutes, forest sector, competitive advantage, pre-competitive research, platform technologies, government, highly qualified personnel
Thinning in mature eastern white pine: 43-year case study
Authors: Anderson Paul D , Zasada John C , Erickson Glen W , Zasada Zigmond A
Published: February 2014

A white pine (Pinus strobus L.) stand at the western margin of the species range, approximately 125 years of age at present, was thinned in 1953 from 33.5 m2 ha-1 to target residual basal areas of 18.4, 23.0, 27.5, and 32.1 m2 ha-1 . Repeated measurement over the following 43-years indicated that the greatest total volume production and the greatest number of large diameter trees occurred in the unit of highest residual density. Over time, the distribution of stems was predominantly random although mortality between 1979 and 1996 resulted in a tendency for clumping in the 23.0 and 27.5 m2 ha-1 treatments. DNA analysis indicated that thinning intensity had little effect on the genetic diversity of residual white pine. This study suggests that mature white pine stands in northern Minnesota may be managed at relatively high densities without loss of productivity. However, regardless of overstory density, there was little or no white pine regeneration occurring in this stand. Key words: thinning, growth, genetic diversity, molecular markers, spatial pattern, regeneration
Learning about community capacity in the Fundy Model Forest
Authors: Chouinard Omer , Perron Johanne
Published: February 2014

The forest plays an important role in New Brunswicks economy. The Fundy Model Forest, located in southeastern New Brunswick developed a multi-stakeholder approach to public participation in sustainable forest management. This paper presents the main results of a research conducted in the year 2000 with representatives of the 31 FMF partner organizations. The objectives of the survey were mainly to verify the responsibility taken by partner organizations in term of community capacity and leadership in communities in order to develop and optimize collaborative management of forest resources. The survey was based on semi-directed interviews. Key words: community capacity, multi-stakeholder, public participation, sustainability, forest management, consensus building, decision making, Fundy Model Forest, individual learning, organizational learning, adaptative management, non-timber values
The International Model Forest Network (IMFN): Elements of Success
Authors: Besseau Peter , Dansou Kafui , Johnson Frederick
Published: February 2014

The International Model Forest Network (IMFN) was announced by Canada at the Rio (UNCED) Summit ten years ago to pilot outside of Canada a promising participatory field-level approach to sustainable forest management then being developed in Canada through its national model forest network. The IMFN has since grown from three sites in two countries (outside of Canada) in 1994 to 19 sites in 11 countries, in addition to numerous additional sites proposed and at early stages of development. Now with the successor event to Rio, the World Summit on Sustainable Development, about to take place in Johannesburg, South Africa, there is an appropriate milestone at which to pause and consider its evolution and growth. Among the elements of success attributed to the growth of the network the authors consider the nature of the approach itself as being an innovative re-formulation of widely shared management values, its flexibility across borders and ecosystems, and the support provided in its development by the Canadian Model Forest Network and other domestic and international partners. The article looks at similarities and differences between the international and Canadian applications of this approach and describes some of the lessons learned and difficulties met in applying the approach internationally. Key words: IMFNS, CMFN, International, Networking, Asia, Latin America
Forest carbon accounting at the operational scale
Authors: Kurz Werner A , Apps Mike , Banfield Ed , Stinson Graham
Published: February 2014

Canadas forests play an important role in the global carbon (C) cycle. Forest management activities, implemented at the operational scale, can have a significant impact on the C budget of Canadas forests. With the increasing national and international recognition that forest management activities can contribute to national C sources and sinks, forest managers could benefit from having a scientifically credible tool to assess the potential impacts of alternate management activities on the C stocks and stock changes on their land base. Such a tool must incorporate the best available science, be compliant with evolving international accounting rules and have enough flexibility to address the types of scenarios and management questions that are of interest to forest managers. To be cost effective and efficient for use by forest managers, the tool should make use of existing information on inventory, growth and yield, and disturbances that their analysts routinely use in their forest management planning activities. The readily available information must be augmented with additional data and modelling to estimate changes in those C pools that are not commonly included in forest inventories, such as carbon in the dead organic matter associated with litter, coarse woody debris and soil C. Building upon the past decade of work in the development and application of the C Budget Model of the Canadian Forest Sector (CBM-CFS2), the Canadian Forest Service C Accounting Team is now working with the Model Forest Network to develop, test and deliver an operational scale C accounting tool and its supporting databases with regional parameter values. When fully developed (2004), the operational model will be made available without charge to anyone interested in using it to estimate landscape level forest C stocks and C stock changes. Expertise developed within the extensive network of Model Forests and their partners in Canada will facilitate technology transfer and training of the larger user community. The tools and the technology transfer program will empower forest managers to include considerations of the impacts of the planned activities on forest C stocks. This will increase the potential use of forests and forest management activities in contributing towards a greenhouse gas emission reduction strategy. Key words: carbon cycle, carbon accounting, forest management, operational scale, land-use change, model forests, CBM-CFS2
A dynamic equation for a published Sitka spruce site-dependent height-age model
Authors: Cieszewski Chris J , Nigh Gordon D
Published: February 2014

We present a new Sitka spruce (Picea sitchensis (Bong.) Carr) site-dependent height-age model that is based on a dynamic site equation simulating previously published height-age curves for various productivity sites. The new model is an improvement over the previous model because it uses any arbitrary height-age pair to directly predict a height at another age, instead of using a fixed base-age site index as the older model does. Consequently, it can also be used directly to compute height at any age from site index or site index from any height and age instead of relying on numerical solutions for site index computations. The model predicts the same heights for any site as the original fixed base-age model and has the same desirable properties of polymorphism, inflection point, variable asymptotes, logical behaviour, theoretical basis, parsimony, and improved extrapolation. The model is offered as an algebraic improvement only, and therefore it was calibrated on pseudo-data generated from the old models predictions rather than on real data. The proposed equation mimics the old model better than the other dynamic equations tested in this study, which is illustrated using examples with the Chapman-Richards function. Analysis with the real data might offer further improvements to the model predictions. Key words: Base-age invariance, height-age model, model properties, nonlinear regression, Sitka spruce, site index
Are plantations changing the tree species composition of New Brunswick's forest?
Authors: Erdle Thom , Pollard Jason
Published: February 2014

Forest plantations are viewed by some as a means to meet the world's escalating demand for wood, and by others as a threat to forest diversity and ecological function. With the purpose of improving planting practices, we analysed recently available data on 15- to 30-year-old plantations on public land in New Brunswick to identify tree species composition differences between plantations and the natural forest they replaced. Presently, 9% of the public forests in the province has been planted; at current planting rates, this will increase to 17% by the year 2030. Plantations established between 1967 and 1982 differ little from the natural forest they replaced in terms of total softwood content, but differ markedly by having much higher jack pine and much lower red spruce contents. There is evidence of reduced diversity evenness in plantations at the landscape level, but at the stand level few plantations are true monocultures and the abundance of high single-species dominance in plantations is very similar to that of the natural forests they replaced. All species composition comparisons between plantations and replaced natural forest vary strongly by ecoregion. To reduce the degree of difference between plantations and the natural forest, planting practices and prescriptions should (a) broaden the mix of species used, and use less jack pine and more red spruce and cedar, (b) employ a mix of species at the stand level, and (c) consider more fully the site conditions and natural species composition of ecological zones. Key words: plantations, tree species composition, forest simplification, tree species diversity, forest management
Indigenous knowledge in sustainable forest management: Community-based approaches achieve greater success
Authors: McGregor Deborah
Published: February 2014

Forests continue to play a critical part in the spiritual and cultural life of Aboriginal people. In turn, Aboriginal people are striving to revitalize their role in maintaining a healthy relationship with these ecosystems. In Canada, the past two centuries have seen Aboriginal people largely excluded from forest management activities. This has begun to gradually change due to ongoing Aboriginal efforts in the courts as well as to national and international recognition of the potential contribution of Indigenous Knowledge to sustainable forest management. Such change is bringing about new opportunities for the meaningful involvement of Aboriginal people and Indigenous Knowledge in sustainable forest management activities. The increasing participation of Aboriginal people in sustainable forest management is both called for and reflected in various forest policies, practices and programs in Canada. While this represents a positive development, the degree and type of Aboriginal involvement called for have thus far generally been unsatisfactory from an Aboriginal perspective. Interviews conducted with both Aboriginal and non-Aboriginal participants in Ontario's new forest management planning process indicate that this recently developed process has nonetheless yielded some hopeful results in terms of Aboriginal involvement in certain instances. It was found that both Aboriginal and non-Aboriginal interview respondents most often described the Aboriginal consultation process to be a success where control over the nature and methods of sharing of information was relinquished to the participating Aboriginal communities. Contexts and implications of these findings are briefly discussed. Key words: Traditional ecological knowledge, native values mapping, Aboriginal forestry, sustainable communities
Saskatchewan forest carbon sequestration project
Authors: Lemprière Tony C , Johnston Mark , Willcocks Al , Bogdanski Bryan , Bisson Deb , Apps Mike , Bussler Oliver
Published: February 2014

In 2002 a project in Saskatchewan became the first forest carbon (C) sequestration project to be formally reviewed and approved in Canada under the Greenhouse Gas Emission Trading (GERT) Pilot. GERT concluded that the project will result in real, measurable, verifiable and surplus net sequestration, calculated as C stock changes in the with-project case less C stock changes in the reference (without project) case. The project is a 50-year agreement (2000–2050) in which Saskatchewan Environment sells net C sequestration to the provincial electrical utility Saskatchewan Power Corporation. Net sequestration of 1.6 Mt C is expected to result from the establishment of white spruce plantations on 3300 ha and from forest protection through creation of 206 000 ha of Forest Carbon Reserves. Issues that arose in the review included leakage, the permanence of the sequestered carbon and risk of losses, establishment of the reference case, methodologies for projections of impacts, approaches for sampling and measurements, and accounting methods. GERT established a number of reporting and other conditions to be fulfilled when estimates of actual net sequestration are registered. Future forest C sequestration projects, project reviews and policy development will be able to draw upon the lessons learned from the Saskatchewan project. Key words: carbon sequestration, carbon sequestration projects, Saskatchewan, Greenhouse Gas Emission Reduction Trading Pilot, plantations, forest protection, leakage, permanence, carbon accounting, carbon measurement
Aspen development on similar soils in Minnesota and British Columbia after compaction and forest floor removal
Authors: Stone Douglas M , Kabzems Richard
Published: February 2014

Forest management practices that decrease soil porosity and remove organic matter can reduce site productivity. We evaluated effects of four treatmentsmerchantable bole harvest (MBH) with three levels of soil compaction (none, light, or heavy), and total woody vegetation harvest plus forest floor removal (FFR)on fifth-year regeneration and growth of aspen (Populus tremuloides Michx.) growing on soils with similar textures (2040 cm silt loam over clay loam till) in northern Minnesota (MN) and northeastern British Columbia (BC). Overall mean sucker density was significantly greater in BC than in MN, and mean height was significantly lower. Soil compaction did not affect sucker density in BC, but significantly reduced it in MN, primarily due to late spring treatment. In BC, mean sucker heights generally decreased with level of compaction, but only the differences between non-compacted and the heavy compaction treatments were significant. On the MN plots, sucker heights were reduced significantly by compaction. Treatment responses were similar on both sites: (1) the greatest sucker densities were in the FFR treatment; (2) greatest mean heights were on the non-compacted MBH plots and were significantly greater than those in the FFR treatment; (3) sucker heights generally decreased with level of compaction; and (4) soil compaction decreased the number of suckers that had reached a dbh of 25 mm after five years and will likely delay future stand development and reduce site productivity. Key words: sustainable management, organic matter removal, soil compaction, aspen sucker density, height growth
Ice storm damage to eastern Ontario forests: 19982001
Authors: Hopkin Anthony , Williams Tim , Sajan Robert , Pedlar John , Nielsen Cathy
Published: February 2014

Following the 1998 ice storm, tree mortality and crown damage were monitored on permanent plots across eastern Ontario from 1998 until 2001. Conifer species were less damaged than hardwoods. Hardwood tree species showing the greatest crown damage included aspen, (Populus tremuloides), basswood (Tilia americana), and white birch (Betula papyrifera); major species showing the least damage included sugar maple (Acer saccharum), red oak (Quercus rubra) and hickory (Carya spp.). Generally, smaller diameter trees showed less damage than larger diameter trees. Significant mortality was recorded to silver maple (Acer saccharinum), basswood, ash (Fraxinus spp.) and aspen in 1998, although mortality in 2000 and 2001 was about 1–2%. Trees sustaining > 75% crown damage usually died by 2001. Key words: ice storm, ice damage, forest health
Ice storm damage: Effects of competition and fertilization on the growth of sugar maple trees
Authors: Lautenschlager R A , Pedlar John H , Winters John A , Nielsen Cathy M
Published: February 2014

Treatment plots in blocks established in productive sugar maple (Acer saccharum) bushes throughout southeastern Ontario were used to quantify effects of fertilizers, vegetation control and interactions on maple growth following the 1998 ice storm. Treatments were applied during the spring of 1999. Increment cores from six mature sugar maple trees in each plot in each block were extracted and examined during October 2001. Maple growth was highly variable before the storm, but fell to a 30-year low during both the first and second year after the storm. Growth reductions increased with increasing crown damage. Treatment-related statistical differences were marginal; however, the data suggest that phosphorus and potassium additions and competition control improved the growth of ice-damaged mature sugar maple trees. The combination of competition control and fertilization increased growth of ice-damaged maple the most. Key words: Acer saccharum, increment cores, glyphosate, phosphorus, potassium
The effect of ice damage and post-damage fertilization and competition control on understory microclimate of sugar maple (Acer saccharum Marsh.) stands
Authors: Parker William C
Published: February 2014

The influence of ice damage, fertilization, and herbicide treatments on understory microclimate was examined in several sugar maple stands during three growing seasons. Stands with greater initial crown damage and lower leaf area index had higher understory light levels, elevated air temperatures and lower humidity. Ice damage had comparatively less effect on the below-ground environment. Stands with higher damage and lower leaf area index exhibited higher soil temperature and lower soil moisture availability in certain years. The strength and significance of the relationships of canopy features with microclimatic variables diminished over time with canopy recovery and growth of understory vegetation. Fertilization treatment effects on stand microclimate were not apparent, but competition control reduced understory leaf area, increased soil temperature, and had minimal influence on soil moisture status. Key words: canopy, fertilization, ice storm, microclimate, natural disturbance, sugar maple, vegetation management
Environmental assessment of forestry in Canada
Authors: Bonnell Steve
Published: February 2014

Environmental assessment (EA) is widely used as a means of identifying and addressing the potential environmental effects of proposed development activities. This paper provides an overview of EA and its application to forest management in Canada. Forestry planning processes in Canada generally include consideration of environmental issues and stakeholder participation, and therefore incorporate key aspects of EA as part of the planning exercise. EA review can, however, provide an opportunity to further assess and consider the potential environmental effects of proposed forestry activities, as required, as well as involve other relevant parties in decision-making. Key words: environmental assessment, forest management, planning, Canada.
The Missing "Missing Sink"
Authors: Nilsson Sten , Jonas Matthias , Stolbovoi Vladimir , Shvidenko Anatoly , Obersteiner Michael , McCallum Ian
Published: February 2014

To assess CO2 fluxes of the terrestrial biosphere, ground-based inventories, flux measurements and bottom-up modeling approaches are used. In most cases inventory-based approaches are not able to produce a full carbon account (FCA). The FCA refers to a carbon budget that is complete, encompasses all components, and is applied continuously in time. Atmospheric inversion modeling implicitly measures the sum of all fluxes, meaning a FCA. Eddy-covariance measurements have huge variations and are difficult to scale up to regional and decadal levels. Bookkeeping up to more complex process-based models rely on land-use change estimates over time, which have large uncertainties. To overcome the accounting gap between top-down and bottom-up measurements, the IPCC introduced the terrestrial "missing sink" concept by taking long-term land-use changes into account to further break down the global carbon budget. IIASA has developed a bottom-up FCA approach that breaks down the terrestrial carbon balance of Russia for 1990 (1988–1992) resulting in a sink. This was then combined with the terrestrial sink strength of the extra-tropical Northern Hemisphere (approximately > 30°N) determined via top-down atmospheric inversion. Using this approach, the remainder, the terrestrial sink strength of the extra-tropical Northern Hemisphere without Russia, could then be determined with a relative uncertainty that is smaller (i.e., < 100%) than the uncertainties exhibited by inverse models. From the analysis it can be concluded that the "missing sink" issue can be reduced to an issue of relevant accounting due to the fact that the combined top-down/bottom-up approach does not identify any missing sink. Key words: carbon balance, flux, missing sink, inverse modeling, inventory approaches, full carbon accounting, top-down/bottom-up approaches, terrestrial ecosystems, Russia
Operational mapping of the land cover of the forested area of Canada with Landsat data: EOSD land cover program
Authors: Wulder M A , Dechka J A , Gillis M A , Luther J E , Hall R J , Beaudoin A. , Franklin S E
Published: February 2014

A priority of the Canadian Forest Service and Canadian Space Agency joint project, Earth Observation for Sustainable Development of Forests (EOSD), is the production of a land cover map of the forested area of Canada based upon Landsat data. The land cover will be produced through a partnership of federal, provincial and territorial governments, universities, and industry. The short-term goal of EOSD is to complete a land cover map representing year 2000 forested area conditions by early 2006. Over the longer term, EOSD will aim to produce land cover products to capture changes in forest conditions over time to support national and international reporting requirements. The forested area of Canada represents approximately half of Canada's landmass, requiring over 450 scenes for complete coverage (with overlap minimized). EOSD is working with provincial and territorial mapping agencies that have on-going land cover mapping programs to optimize production capacity. It is envisioned that the combined output of EOSD and provincial and territorial land cover mapping programs will be integrated with maps developed by other sectors and agencies (such as agriculture) to produce a complete representation of the land cover of Canada. Large-area land cover mapping using remote sensing is a relatively new phenomenon. Advances in data storage capabilities, computing power, and increases in the affordability of data have allowed for large-area projects to be undertaken in ways previously not possible. The manner in which a large-area mapping project is approached is related to a number of factors including the spatial extent of the area of interest, the spatial resolution of the selected sensor, and the products which are to be generated. In this communication we report on the strategy, methods, and status of the EOSD land cover mapping program of the forested area of Canada. Key words: Canada, land cover, forest inventory, EOSD, Landsat, unsupervised classification, NFI
Synthesizing published knowledge of boreal forest cover change for large-scale landscape dynamics modelling
Authors: Yemshanov Dennis , Perera Ajith H
Published: February 2014

We reviewed the published knowledge on forest succession in the North American boreal biome for its applicability in modelling forest cover change over large extents. At broader scales, forest succession can be viewed as forest cover change over time. Quantitative case studies of forest succession in peer-reviewed literature are reliable sources of information about changes in forest canopy composition. We reviewed the following aspects of forest succession in literature: disturbances; pathways of post-disturbance forest cover change; timing of successional steps; probabilities of post-disturbance forest cover change, and effects of geographic location and ecological site conditions on forest cover change. The results from studies in the literature, which were mostly based on sample plot observations, appeared to be sufficient to describe boreal forest cover change as a generalized discrete-state transition process, with the discrete states denoted by tree species dominance. In this paper, we outline an approach for incorporating published knowledge on forest succession into stochastic simulation models of boreal forest cover change in a standardized manner. We found that the lack of details in the literature on long-term forest succession, particularly on the influence of pre-disturbance forest cover composition, may be limiting factors in parameterizing simulation models. We suggest that the simulation models based on published information can provide a good foundation as null models, which can be further calibrated as detailed quantitative information on forest cover change becomes available. Key words: probabilistic model, transition matrix, boreal biome, landscape ecology
Multi-scale species modelling in Ontario: A workshop on needs and opportunities
Authors: Lipsett-Moore Geoff , McKenney Dan , Jones Scott
Published: February 2014

A workshop on multi-scale species modelling was recently held in Sault Ste. Marie, Ontario. We reviewed Australian experiences with this type of spatial modelling (including development and validation of different approaches) and current needs, activities and impediments to species modelling in Ontario. Multi-scale species modelling can support regional conservation planning, the design of monitoring activities, forest planning and indicator development. Several recommendations were generated. Key words: spatial modelling, GLM, GAM, monitoring, indicators, conservation planning
Why mountain forests are important
Authors: Price Martin F
Published: February 2014

Mountains cover 24% of the Earths land surface, are home to 12% of the global population, and include 28% of the worlds forests. Mountain forests provide a wide range of benefits to both mountain and downstream populations, notably the protection of watersheds and of transport infrastructure. They are also important as centres of biodiversity; important sources of timber, fuelwood and non-wood products; places for tourism and recreation; and sacred places. Many are also being considered as possible carbon sinks to mitigate climate change. Mountain forests are subject to many forces of change, interacting in complex ways. The frequency of natural disturbances is increasingly influenced by human activities at local, regional, and global scales. Air pollution has influenced many forests downwind of industrial areas, but climate change represents a greater and highly unpredictable force for change. It will require new types of decisions by all stakeholders, and new forest management approaches and policies. The International Year of Mountains, 2002, presents a unique opportunity to foster greater co-operation to ensure that mountain forests continue to provide benefits to a significant proportion of the worlds population well into the 21st century and beyond. Key words: forests, sustainable development, mountains, climate change, co-operation
Altitudinal treelines of the southern Andes near 40ºS
Authors: Daniels Lori D , Veblen Thomas T
Published: February 2014

In the southern Andes near 40ºS, altitudinal treelines are dominated by Nothofagus pumilio, a broadleaf deciduous angiosperm in the beech family (Fagaceae). Treeline elevations, ranging from 1100 to 1500 m a.s.l., are influenced by regional climate and volcanism. At the local scale, disturbance influences treeline elevation, ecotone length, and vegetation productivity. Decadal and interannual variation in climate related to El Niño-Southern Oscillation (ENSO) significantly affected radial growth of krummholz trees and seedling demography; however, climate-treeline relations were complex. Radial growth of krummholz trees and seedling demography responded differently to climate variation. These relations differed between climate regions and were unstable through time. We conclude that inter-annual variations in climate, such as those associated with ENSO, will be critical for successful reproduction and growth of Nothofagus pumilio at treeline in the Andes under the influence of global warming. Key words:Argentina, Chile, climate change, disturbance, forest dynamics, global warming, northern Patagonia, Nothofagus pumilio, South America, timberline
Ecological variability of high elevation forests in central British Columbia
Authors: DeLong Craig , Meidinger Del
Published: February 2014

High-elevation, late-successional forests over much of British Columbia are dominated by Engelmann spruce (Picea engelmannii Parry ex. Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). Throughout the range of these forests, however, there is a wide variation in natural disturbance and successional dynamics as influenced by diverse climate and topography. We divided these high elevation forests into four groups arranged along a regional climatic gradient that affects forest composition, structure and disturbance regime. For each, we describe the climate, topography, major vegetation, and natural disturbance dynamics. We suggest that management practices reflect the ecological variability demonstrated for these high elevation forests. Key words: high elevation forests, ecological variability, natural disturbance dynamics, vegetation, Engelmann spruce, subalpine fir, British Columbia, climate, topography
Forestry on fans: a problem analysis
Authors: Wilford David , Sakals Matt , Innes John
Published: February 2014

Forested fans are often crossed by roads and their high-volume stands are attractive for harvesting. Gentle slopes of fans belie the fact that hydrogeomorphic hazards can be present. Fans can be the run out zones for debris flows and they can be subject to floods and debris floods. This study assessed the effect of natural hydrogeomorphic processes on forest practices that were undertaken on 55 fans in west central British Columbia. Forest practices aggravated these processes on 41 (74%) fans, leading to increased erosion and destabilization of fan surfaces and stream channels. Identification of hydrogeomorphic hazards is needed to avoid the adverse effects of forestry practices on fans. Key words: forested fans, forestry on fans, hydrogeomorphic processes, forest practices on fans, forest practices
A note on the ecology and management of old-growth forests in the Montane Cordillera
Authors: Arsenault André
Published: February 2014

The Montane Cordillera ecozone that spans British Columbia's central and southern interior and a portion of southwestern Alberta contains the greatest variety of old-growth coniferous forest types in Canada. The diverse climates of this region, which include some of the driest, warmest, wettest, and coldest found in southern continental Canada, have directly contributed to the richness of old forest types. Associated with this range in climatic conditions are radically different natural disturbance regimes that have profoundly influenced the distribution, abundance, and structural characteristics of old-growth forests. Old forests tend to be more abundant and to contain more old-growth-dependent organisms in wetter climates. The high number of old-growth-dependent epiphytic lichens in old inland rainforests is a clear expression of this phenomenon. Conversely, old forests are much less abundant in dry landscapes. These forests, often dominated by Ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), have been subject to more frequent natural disturbances, and have been more profoundly influenced by human activities. Although fewer species appear to be dependent on old growth in dry forests, a number of them require certain old-growth structural attributes for their survival. A better understanding of the ecological characteristics of the old-growth forests of Canada's Montane Cordillera will assist in developing informed land-use decisions. Key words: old-growth forest, Montane Cordillera, natural disturbance, landscape ecology and management
West coast, temperate, old-growth forests
Authors: MacKinnon Andy
Published: February 2014

Canada's west coast, temperate, old-growth forests include its largest, most commercially valuable, fastest-growing, oldest, and certainly most fought-over forests. They can be divided into three main types: coastal rainforest, coastal subalpine forest, and "rain-shadow" forest. Although there is great variation within each of these broad types, coastal rainforests and subalpine forests share a wet climate and are relatively unimpacted by fire as a stand-replacing disturbance. This allows development of multi-aged, multi-canopy, old-growth forests with large volumes of living and dead wood. These forests are structurally and biologically complex. Coastal rain-shadow forests, on the other hand, have a distinctively drier climate (for the coast), and a history of frequent, low-intensity fires. Although well over half of Canada's original west coast, temperate, old-growth forests remain as old growth, there is great variation ecologically and geographically. In general, the percentage of old-growth forest remaining increases with increasing latitude and elevation. Key words: old growth, old-growth forest, coastal British Columbia, temperate rainforest, protected areas, stand structure
The changing disturbance regime of the boreal forest of the Canadian Prairie Provinces
Authors: Timoney K P
Published: February 2014

The subhumid boreal forest of western Canada is different today from what it was 25 years ago. Before the 1950s, the main human impacts on this forest were agricultural expansion, escaped settlement fires, and high-grade logging. The latter half of the 20th Century saw increased human stresses placed on the ecosystems, against a background of insect outbreaks and high forest fire activity. In the Prairie provinces, current annual area burned is greater and more variable than it was in the 1970s. Over the past 25 years, the area disturbed by insects (primarily forest tent caterpillar) and disease has declined, but both the area and timber volume logged have risen. The boreal forest (particularly its southern half) is being converted to a fragmented landscape dominated by young aspen, shrub, grass, plantations, exotic species, industrial infrastructure, and agricultural fields. The current disturbance level has increased to the point that forest land and volume losses now exceed forest accruals in some regions; average forest age and biomass have been declining since about 1970. Relative to past decades, the present subhumid boreal forest region of Canada is warmer, and more fragmented and dissected; it supports less old growth, less old white spruce, and more young aspen and recently disturbed areas; it has simplified and truncated age-class structures; and it has a greater prevalence of non-native plants. Future stresses may include in situ tar sands development, groundwater depletion or degradation, and water diversions. Should present trends continue, declining forest productivity and predictability, and spread of exotic species are likely, as is replacement of coniferous forest by deciduous forest in some regions. Stressed aquatic systems may undergo major changes in biotic composition, productivity, and physical characteristics. Without a rapid decrease in the rate of disturbances, the establishment of a more complete protected areas network, and the adoption of ecosystem-centred management, the subhumid boreal ecosystem will continue to be degraded. Key words: climate, defoliation, ecosystem, fire, logging, perturbation, petroleum, vegetation
Western redcedar population dynamics in old-growth forests: Contrasting ecological paradigms using tree rings
Authors: Daniels Lori D
Published: February 2014

In coastal British Columbia, late-successional forests dominated by western redcedar (Thuja plicata Donn ex D. Don) are structurally complex, with deep multi-layered canopies, large trees that are > 250 years old, and abundant coarse woody debris (CWD). These forests are presumed to be "old-growth" forests in which fine-scale gaps are the dominant disturbance regime, accounting for their structural diversity. In this study, I have used tree-ring analyses to investigate western redcedar regeneration dynamics in these old-growth forests. Western redcedar dominates canopies of many stands, but is rare in the understorey although it tolerates shade. The traditional interpretation is that western redcedar depends on catastrophic disturbance to regenerate and that it is replaced through succession by western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes), which are abundant in the understorey. Dominant trees are perceived to represent an even-aged, post-disturbance cohort and the lack of regeneration indicates a population decline in the absence of catastrophic disturbances. In this paper, I investigate four assumptions underlying this interpretation: (1) Tree size indicates age. (2) Populations establish as even-aged, post-disturbance cohorts. (3) Abundant CWD represents recent mortality. (4) Regeneration is insufficient to maintain canopy dominance. Using tree-ring evidence, I show that population dynamics of western redcedar are a combination of gap-phase establishment and a continuous mode of recruitment from the sub-canopy to the canopy. Specifically, size is a poor surrogate for tree age. Age distributions from 15 sites revealed uneven-aged populations, rather than single post-disturbance cohorts. Both logs and snags of western redcedar may persist more than 270 years; they do not represent recent mortality that is disproportionate to the number of live western redcedar in canopy. The regeneration niches of western redcedar and western hemlock overlap. For both species, gap-phase disturbances result in substrate suitable for successful seedling establishment. Preliminary results from dendroecological analysis of radial growth rates of trees in the subcanopy and canopy strata suggest that western hemlock and Pacific silver fir depend on gaps to recruit to the upper canopy, but recruitment of western redcedar may be independent of canopy gaps. I propose that differences in mode of recruitment to the canopy may explain the differences in population structures between western redcedar, western hemlock, and Pacific silver fir in the old-growth forest. These results provide an ecological precedent for use of a range of silvicultural systems, including clearcuts through single-tree harvesting and protection forests, when managing western redcedar in coastal British Columbia. Key words: Coastal British Columbia, disturbance regimes, regeneration dynamics, Thuja plicata, variable retention silviculture
Les communautés d'oiseaux des vieilles forêts de la pessière à mousses de la ceinture d'argile : Problèmes et solutions face à l'aménagement forestier
Authors: Drapeau Pierre , Leduc Alain , Bergeron Yves , Gauthier Sylvie , Savard Jean-Pierre
Published: February 2014

In Canada, there are still extensive tracts of boreal forest consisting of stands that have resulted from natural disturbances. The country's forests are a mosaic made up to a large extent of old-growth forest that is beyond commercial harvesting age, especially in the boreal forest of eastern Canada. As areas of boreal forest under management steadily expand, as demand for forest products continues to grow and as rotation periods become shorter in response to silvicultural practices, the forest cover will inevitably become younger, causing changes to the structure and composition of the mosaic of forest stands that will affect the aspect of entire landscapes. These changes may have an adverse impact on biological diversity. Forest birds are one group of living organisms that may respond quickly to the advent of younger forest landscapes, thereby acting as a biological indicator. In this paper, we discuss some of the problems that birds face as a result of the truncation of the age-class distribution of managed forest landscapes in eastern Canada's coniferous boreal forest, using data obtained from our research in the Clay Belt region of Quebec and Ontario. More specifically, we look at how birds respond to changes in forest structure and composition in terms of time since natural disturbances, and to variation in dead trees availability. We then consider the impact of the prospective rejuvenation of the forest cover in managed forest landscapes, and possible solutions aimed at mitigating that impact through new management strategies based on the maintenance of forest ecosystem diversity. The ability of these new management strategies to maintain the ecological integrity of bird communities provides an indication of their potential as tools for contributing to the maintenance of biological diversity in a broader sense. Key words: bird communities, old black spruce forests, natural landscape age structure, stand structure, dead wood, multicohort management
Snag abundance 20, 30, and 40 years following fire and harvesting in boreal forests
Authors: Ferguson Steven H , Elkie Philip C
Published: February 2014

The retention of standing dead trees (snags) has become an important conservation concern, especially when forest management efforts attempt to emulate natural disturbance. We investigate the abundance of snags within Ontario's boreal forest following 10–20, 21–30, and 31–40 years of both fire and forest harvest disturbance over a 24 000-km2area. Fire frequency varied considerably, with 90% of the fires in the study area occurring in the 1970s. We did not detect differences in basal area of snags (m2/km2) between burned and harvested stands. However, differences occurred in dead-stem density (number/km2); the burned stands produced more snags in the 21- to 30-year post-disturbance class and the harvested stands produced more snags in the 31- to 40-year post-disturbance class. Similarly, the distribution of diameter classes of snags differed between the burned and harvested stands. In size classes greater than 32 cm (diameter at breast height), we found more snags in the harvested forests 21–40 years following disturbance. We did not find differences in the basal area of snags between disturbance types, whether they were hardwood or softwood. However, hardwood snags occurred in greater abundance in the larger diameter classes. Our findings are limited by the changing timber harvest treatments (selective harvest, clearcut, and ecological cut), the small number of disturbance events, and the variety of stand compositions. More research is required on the ecological factors influencing snag abundance to improve development of local forest management plans and to design landscapes that conserve forest structure and biodiversity. Key words: biodiversity, clearcut, conservation, coarse woody debris, dead trees, forest management, landscape, snags, wildlife