Forest Management Scenarios Research Articles

Assessing the Effects of Management Alternatives on Habitat Suitability in a Forested Landscape of Northeastern China

Forest management often has cumulative, long-lasting effects on wildlife habitat suitability and the effects may be impractical to evaluate using landscape-scale field experiments. To understand such effects, we linked a spatially explicit landscape disturbance and succession model (LANDIS) with habitat suitability index (HSI) models to assess the effects of management alternatives on habitat suitability in a forested landscape of northeastern China. LANDIS was applied to simulate future forest landscape changes under four management alternatives (no cutting, clearcutting, selective cutting I and II) over a 200-year horizon. The simulation outputs were linked with HSI models for three wildlife species, the red squirrel (Sciurus vulgaris), the red deer (Cervus elaphus) and the hazel grouse (Bonasa bonasia). These species are chosen because they represent numerous species that have distinct habitat requirements in our study area. We assessed their habitat suitability based on the mean HSI values, which is a measure of the average habitat quality. Our simulation results showed that no one management scenario was the best for all species and various forest management scenarios would lead to conflicting wildlife habitat outcomes. How to choose a scenario is dependent on the trade-off of economical, ecological and social goals. Our modeling effort could provide decision makers with relative comparisons among management scenarios from the perspective of biodiversity conservation. The general simulation results were expected based on our knowledge of forest management and habitat relationships of the species, which confirmed that the coupled modeling approach correctly simulated the assumed relationships between the wildlife, forest composition, age structure, and spatial configuration of habitat. However, several emergent results revealed the unexpected outcomes that a management scenario may lead to.

Assessing the sustainability of forest management: An application of multi-criteria decision analysis to community forests in northern Ethiopia

Continuous deterioration of the natural resource base has become a serious threat to both the ecological systems and economic production in Ethiopia. Many of these problems have been attributed directly or indirectly to the rapid dwindling of the country's forest cover which is associated with unsustainable forest use and management. Closing community woodlands from human and livestock intervention to promote natural regeneration of forests has been one of the environmental restoration strategies pursued in the degraded highland areas of northern Ethiopia. However, local pressure to use reforested community lands for economic benefit has become a major threat to forest sustainability. Using locally identified sets of criteria and indicators for sustainable community forest management, this paper applies a multi-criteria decision analysis tool to evaluate forest management problems in the northern province of Tigray, Ethiopia. Three MCA methods – ranking, pair-wise comparison, and scoring – were used in evaluating the sets of criteria and indicators and alternative forest management scenarios. Results from the study indicate a number of noteworthy points: 1) MCA techniques both for identifying local level sustainability criteria and indicators and evaluating management schemes in a participatory decision environment appear to be effective tools to address local resource management problems; 2) Evaluated against the selected sets of criteria and indicators, the current forest management regime in the study area is not on a sustainable path; 3) Acquainting local people with adequate environmental knowledge and raising local awareness about the long-term consequences of environmental degradation ranked first among the set of sustainability criteria; and 4) In order to harmonize both environmental and economic objectives, the present ‘ecological-biased’ forest management regime needs to be substituted by an appropriate holistic scheme that takes into account stakeholders' multiple preferences and priority rankings.

Forest restoration in a mixed‐ownership landscape under climate change

The extent to which current landscapes deviate from the historical range of natural variability (RNV) is a common means of defining and ranking regional conservation targets. However, climate-induced shifts in forest composition may render obsolete restoration strategies and conservation targets based on historic climate conditions and disturbance regimes. We used a spatially explicit forest ecosystem model, LANDIS-II, to simulate the interaction of climate change and forest management in northeastern Minnesota, USA. We assessed the relevance of restoration strategies and conservation targets based on the RNV in the context of future climate change. Three climate scenarios (no climate change, low emissions, and high emissions) were simulated with three forest management scenarios: no harvest, current management, and a restoration-based approach where harvest activity mimicked the frequency, severity, and size distribution of historic natural disturbance regimes. Under climate change there was a trend toward homogenization of forest conditions due to the widespread expansion of systems dominated by maple (Acer spp.). White spruce (Picea glauca), balsam fir (Abies balsamea), and paper birch (Betula papyrifera) were extirpated from the landscape irrespective of management activity; additional losses of black spruce (P. mariana), red pine (Pinus resinosa), and jack pine (P. banksiana) were projected in the high-emissions scenario. In the restoration management scenario, retention and conversion to white pine (P. strobus) restricted maple expansion. But, widespread forest loss in the restoration scenario under high-emissions projections illustrates the potential pitfalls of implementing an RNV management approach in a system that is not compositionally similar to the historic reference condition. Given the uncertainty associated with climate change, ensuring a diversity of species and conditions within forested landscapes may be the most effective means of ensuring the future resistance of ecosystems to climate-induced declines in productivity.

Increasing carbon sinks through forest management: a model-based comparison for Switzerland with its Eastern Plateau and Eastern Alps

The Kyoto Protocol brought a new forest function into focus: forests as carbon sinks. This new forest function may lead to new conflicts, because on the one hand, Switzerland has decided to account for forest management under Kyoto Protocol (Article 3.4), and on the other hand, Swiss Forestry statistics and the Swiss National Forest Inventory indicate that increasing amounts of wood are being harvested. This trend seems likely to continue. In this study, we used the empirical forest model MASSIMO and the soil model YASSO to analyse four different forest management scenarios. These scenarios basically feature different levels of harvesting frequencies and different rotation length, as well as their impact on regional potentials for carbon sequestration and harvesting amounts. Results were analysed both for the whole of Switzerland and for two very different regions: The Swiss Eastern Plateau and the Swiss Eastern Alps. The results indicate that Swiss forests can provide an increasing amount of harvested wood (+18% in relation to the base year 1996) for approximately 20 years and act as a carbon sink accountable under the Kyoto Protocol (0.5 million tons carbon per year). The corresponding forest management strategy aims for a sustainable and harvestable increment and may, therefore, avoid spurious carbon maximization in forests that can happen by accounting for only forest systems, and not for the effect of substitution of non-wood products and fossil fuels by forest products. The regional results indicate that (1) the carbon sink effect of Alpine forests in Switzerland might be limited, because generally, Alpine forests have low growth and yield and (2) a large increase in harvesting may lead to regional carbon sources and necessitate regional monitoring of increment to avoid overexploitation. As MASSIMO does not include the impacts of climate change, the conclusions of this study cannot be interpreted as actual predictions into the future but portray the impact of the applied management actions on the respective trends in carbon stocks and stock changes. They are, therefore, a contribution to support future management decisions. Further studies should focus on interactions with additional forest functions such as the preservation of biodiversity, increase the consideration of forest damage and account for the effect of climate change.

Forest carbon storage in the northeastern United States: Net effects of harvesting frequency, post-harvest retention, and wood products

Temperate forests are an important carbon sink, yet there is debate regarding the net effect of forest management practices on carbon storage. Few studies have investigated the effects of different silvicultural systems on forest carbon stocks, and the relative strength of in situ forest carbon versus wood products pools remains in question. Our research describes (1) the impact of harvesting frequency and proportion of post-harvest structural retention on carbon storage in northern hardwood-conifer forests, and (2) tests the significance of including harvested wood products in carbon accounting at the stand scale. We stratified Forest Inventory and Analysis (FIA) plots to control for environmental, forest structural and compositional variables, resulting in 32 FIA plots distributed throughout the northeastern U.S. We used the USDA Forest Service's Forest Vegetation Simulator to project stand development over a 160 year period under nine different forest management scenarios. Simulated treatments represented a gradient of increasing structural retention and decreasing harvesting frequencies, including a “no harvest” scenario. The simulations incorporated carbon flux between aboveground forest biomass (dead and live pools) and harvested wood products. Mean carbon storage over the simulation period was calculated for each silvicultural scenario. We investigated tradeoffs among scenarios using a factorial treatment design and two-way ANOVA. Mean carbon sequestration was significantly ( α = 0.05) greater for “no management” compared to any of the active management scenarios. Of the harvest treatments, those favoring high levels of structural retention and decreased harvesting frequency stored the greatest amounts of carbon. Classification and regression tree analysis showed that management scenario was the strongest predictor of total carbon storage, though site-specific variables were important secondary predictors. In order to isolate the effect of in situ forest carbon storage and harvested wood products, we did not include the emissions benefits associated with substituting wood fiber for other construction materials or energy sources. Modeling results from this study show that harvesting frequency and structural retention significantly affect mean carbon storage. Our results illustrate the importance of both post-harvest forest structure and harvesting frequency in carbon storage, and are valuable to land owners interested in managing forests for carbon sequestration.

Effects of a Severe Mountain Pine Beetle Epidemic in Western Alberta, Canada under Two Forest Management Scenarios

We used a simulation model to investigate possible effects of a severe mountain pine beetle (Dendroctonus ponderosaeHopkins) epidemic under two management scenarios in Alberta, Canada. Our simulated outbreak was based on the current epidemic in British Columbia, which may kill close to 80% of the province's pine volume. Our two management scenarios were conventional harvest and a pine-reduction strategy modeled on a component of Alberta's Mountain Pine Beetle Management Strategy. The pine strategy seeks to reduce the number of susceptible pine stands by 75% over the next 20 years through targeted harvesting by the forest industry. Our simulations showed that the pine strategy could not be effectively implemented, even if the onset of the beetle outbreak was delayed for 20 years. Even though we increased mill capacity by 20% and directed all harvesting to high volume pine stands during the pine strategy's surge cut, the amount of highly susceptible pine was reduced by only 43%. Additional pine volume remained within mixed stands that were not targeted by the pine strategy. When the outbreak occurred in each scenario, sufficient pine remained on the landscape for the beetle to cause the timber supply to collapse. Alternative management approaches and avenues for future research are discussed.

Compromise Programming in Forest Management

Multi-objective decision-making (MODM) is an appropriate approach for evaluating a forest management scenario involving multiple interests. Today's land managers must accommodate commercial as well as non-commercial objectives that may be expressed quantitatively and/or qualitatively, and respond to social, political, economic and cultural changes. The spatial and temporal characteristics of a forest ecosystem and the huge number of variables involved require the management of such a system in a spatiotemporal MODM framework. The particular MODM technique used in this paper is Compromise Programming. This technique is used to determine the most satisfactory management option, Compromise Programming uses a common management response indicator to solve a forest ecosystem management scenario in a fair and equitable manner.

Comparing different forest zoning options for landscape-scale management of the boreal forest: Possible benefits of the TRIAD

Forest management has been criticised in the last 20 years for its negative impact on the native species, structures and functions of the forest. Of many possible alternatives proposed to minimize these effects, the functional zoning (or TRIAD) approach is gaining popularity in North America. The goal of this approach is to minimize the negative environmental impacts of forestry while maintain timber supply by dividing the forest into three broad land-use zones: (1) conservation, (2) ecosystem management, and (3) wood production. In this study, we used a spatially explicit landscape model to simulate the effects of fire and six different forest management scenarios on a boreal mixedwood forest management unit in central Quebec. The management scenarios examined included the current practices scenario, a scenario proposed by the provincial government, and four TRIAD scenarios varying in the amount of forest allocated to each of the three zones. For each scenario, we examined the harvest volume, percentage old-growth forest or old forest managed to favour old-growth attributes, and effective mesh size of forest patches by 20-year age classes. With more area set aside for conservation and high-retention partial cut harvesting techniques designed to maintain the attributes of old-growth stands, all TRIAD scenarios resulted in higher percentages of stands with old-growth attributes than the current practices scenario and the government proposed scenario, and two of the four TRIAD scenarios also resulted in higher harvest volume over the long term. All forest management scenarios resulted in significantly lower effective mesh size than the fire-only scenario, but this difference was not as pronounced for the four TRIAD scenarios as for the current practice and government proposed scenarios. We conclude that the TRIAD approach has the potential to minimize some of the negative impacts of forestry on the landscape, while maintaining timber supply over the long term.

National and global greenhouse gas dynamics of different forest management and wood use scenarios: a model-based assessment

An increased use of wood products and an adequate management of forests can help to mitigate climate change. However, planning horizons and response time to changes in forest management are usually long and the respective GHG effects related to the use of wood depend on the availability of harvested wood. Therefore, an integral long-term strategic approach is required to formulate the most effective forest and wood management strategies for mitigating climate change. The greenhouse gas (GHG) dynamics related to the production, use and disposal of wood products are manifold and show a complex time pattern. On the one hand, wood products can be considered as a carbon pool, as is the forest itself. On the other hand, an increased use of wood can lead to the substitution of usually more energy-intense materials and to the substitution of fossil fuels when the thermal energy of wood is recovered. Country-specific import/export flows of wood products and their alternative products as well as their processing stage have to be considered if substitution effects are assessed on a national basis. We present an integral model-based approach to evaluate the GHG impacts of various forest management and wood use scenarios. Our approach allows us to analyse the complex temporal and spatial patterns of GHG emissions and removals including trade-offs of different forest management and wood use strategies. This study shows that the contributions of the forestry and timber sector to mitigate climate change can be optimized with the following key recommendations: (1) the maximum possible, sustainable increment should be generated in the forest, taking into account biodiversity conservation as well as the long-term preservation of soil quality and growth performance; (2) this increment should be harvested continuously; (3) the harvested wood should be processed in accordance with the principle of cascade use, i.e. first be used as a material as long as possible, preferably in structural components; (4) waste wood that is not suitable for further use should be used to generate energy. Political strategies to solely increase the use of wood as a biofuel cannot be considered efficient from a climate perspective; (5) forest management strategies to enhance carbon sinks in forests via reduced harvesting are not only ineffective because of a compensatory increase in fossil fuel consumption for the production of non-wooden products and thermal energy but also because of the Kyoto-“cap” that limits the accountability of GHG removals by sinks under Article 3.3 and 3.4, at least for the first commitment period; (6) the effect of substitution through the material and energy use of wood is more significant and sustained as compared with the stock effects in wood products, which tend towards new steady-state flow equilibria with no further increase of C stocks; (7) from a global perspective, the effect of material substitution exceeds that of energy recovery from wood. In the Swiss context, however, the energy recovery from wood generates a greater substitution effect than material substitution.

A companion modelling approach applied to forest management planning

To assist the Société Civile des Terres du Larzac (SCTL) in its effort to develop alternative forest management plans, a group of researchers and extension officers proposed applying a companion modelling approach. The objective was to support forest owners and livestock farmers while they worked out a solution to their forest management problems. The approach was based on the co-construction and use of an agent-based model providing a shared representation of the current management of farms and providing multiple view points on alternative forest management scenarios. The validation of the model allowed the development of a shared representation of the territory. The use of the model as an exploratory tool empowered local stakeholders to elaborate alternative management strategies for their renewable resources (forage, timber, firewood). It also expanded the discussion on forest management to a multi-scale level where managers assumed progressively a role of land administrators. When playing this role, they compared their forest policy orientations and forest harvesting decisions with farmers’ individual situations and interests. Participants became aware of how spatial and temporal scales of management overlap and they progressively worked out a compromise between livestock breeding concerns of farmers and forest dynamics concerns of SCTL managers.

A meta-regression analysis of forest carbon offset costs

The main focus of efforts to mitigate climate change is on the avoidance of fossil fuel emissions. However, the Kyoto Protocol rules permit the use of forestry activities that create carbon offset credits. These could obviate the need for lifestyle-changing reductions in fossil fuel use. Therefore, it is necessary for policy purpose to determine the cost effectiveness of creating forest sink carbon credits. In this study, meta-regression analyses with 1047 observations from 68 studies are used to determine factors that affect carbon sequestration costs. Results indicate that forest plantations and use of harvested biomass for energy make forestry activities more attractive. It also turns out that forestry activities are competitive with emissions reduction in tropical regions and, perhaps, boreal regions but certainly not in Europe. Finally, the regression estimates are used to project the potential costs of carbon uptake for various forest management scenarios — costs range from 0 to over 200 US$/t CO2.

Views of Aboriginal People in Northern Ontario on Ontario’s approach to Aboriginal values in forest management planning

Qualitative research through focus groups and semi-structured interviews was conducted with members of 6 northern Ontario Aboriginal communities to obtain their views on how to define and protect Aboriginal values during forest management. Landscape visualization models were used for forest management scenario illustrations. Research results show that: (1) Aboriginal people take an all-encompassing view when discussing Aboriginal values; (2) some of the terminology used in forest management planning regarding Aboriginal values can be confusing to Aboriginal people; and (3) individual Aboriginal values are sometimes spatially defined as more than the physical objects that represent them. One of the conclusions of the research is that Ontario forest management planning needs a separate guide on defining and protecting Aboriginal values. Key words: Aboriginal values, forest management planning, land use, trappers’ cabin, spiritual site, burial site, landscape visualization

Landscape-level habitat supply modelling to develop and evaluate management practices that maintain diverse forest values in a dry forest ecosystem in southern British Columbia

We used the TELSA forest landscape model to examine the long-term consequences of applying different forest management scenarios on indicators of wildlife habitat, understory productivity, crown fuel hazard, timber yield and treatment costs. The study area was a dry forest dominated landscape of approximately 100 000 ha near Kamloops, BC where fire safe communities, timber harvest and the maintenance of biodiversity are important social expectations. Conventional partial cut harvesting treatments maintained timber yields but strongly reduced the area supporting high snag densities, provided low levels of understory productivity and diminished the area that was undisturbed for extended periods. In contrast, the application of extensive fuel management treatments designed to prevent extreme fire behaviour diminished timber flow, but, as with partial cut harvesting, reduced the area with high snag densities and extended periods without disturbance. The application and maintenance of extensive fuel management treatments was also the most costly treatment. Alternatives, such as strategically placed fuel management treatments in critical zones around communities or areas with high investments, diminished costs and somewhat mitigated the reduction in snag densities. More complex land use zoning approaches that incorporate specific practices (e.g. protected areas) to maintain high quality wildlife habitat, and treatments that promote productive understories, appear to hold promise if multiple forest values and objectives are to be maintained in the long-term. We conclude that forest landscape modelling can and should be used to assess the consequences of current or new management initiatives prior to their application to ensure expectations regarding costs and achievement of objectives are realistic.

Modelling human impacts on the Tasmanian wedge-tailed eagle ( Aquila audax fleayi)

The wedge-tailed eagle is Australia’s largest bird of prey and one of the largest eagles in the world. Aquila audax fleayi is an endemic Tasmanian subspecies isolated for 10,000 years from the nominate subspecies on the Australian mainland. The Tasmanian wedge-tailed eagle is classified nationally and at a State level as endangered due to its small number of breeding pairs, low breeding success and high rate of mortality from unnatural causes. The subspecies experiences mortality throughout its range from shooting, poisoning, trapping, road accidents, electrocutions and collisions with wind turbines, aircraft, fences and overhead wires, which we term ‘un-natural mortality’. A portion of the subspecies’ range is managed for timber production, which can lead to disturbance of nest sites and the loss of nest trees. We use a model of the eagle population from the Bass District in northeast Tasmania to explore the relative importance of different sources of mortality and nesting habitat loss, and the potential for mitigating impacts associated with unnatural mortality, disturbance, nesting habitat loss and human access to forests. We create a habitat map including suitable nest sites and link it to a dynamic landscape population model based on life history traits and disturbance responses. Using the program RAMAS-Landscape, we model alternative forest management scenarios, ranging from no timber harvesting and a natural wildfire regime, to scenarios prescribing native forest harvesting and regeneration and different levels of conversion of native forest to plantation under the same natural wildfire regime. The results indicate that the Tasmanian wedge-tailed eagle is sensitive to unnatural mortality, plantation establishment and native forest harvesting. The predicted decline over the next 160 years (∼65%) will most likely be driven largely by loss of current and potential future nest sites associated with harvesting activities, exacerbated by unnatural mortality in the wider landscape. Interventions that minimise unnatural mortality, reduce nest disturbance, and retain breeding habitat and nest sites may improve the prospects for the subspecies in the Bass District. If nest disturbance and unnatural mortality continue at the rates modelled here, the species appears to face a high risk of declining substantially in the region.

GIS and Intelligent Agents for Multiobjective Natural Resource Allocation: A Reinforcement Learning Approach

AbstractAn important component of natural resource management is determining how to allocate resources within a landscape to different stakeholders in a manner that satisfies multiple objectives. Developing decision making tools for assisting natural resource allocation is a challenging endeavor as stakeholders' objectives typically exist at varying spatial scales, their actions are defined by the spatial constraints in which they operate, and the spatial distribution of resources can be altered due to system disturbances. The nature of such challenges suggests the need for a geographic approach that can investigate these spatial complexities in order to generate a suitable set of solutions. The objective of this study is to develop and evaluate an Intelligent Agent Model for multiobjective natural resource allocation. The model integrates agent‐based modeling in a GIS environment with reinforcement learning – a heuristic method for generating, evaluating, and improving multiobjective decision making solutions. The model is implemented by simulating a forest management scenario in which agents that represent forest companies learn how to harvest trees in a manner that maximizes economic return while minimizing the adverse ecological impact to the surrounding landscape. In addition, the model simulates forest disturbances of varying frequencies and intensities to determine how disturbance events affect the decision‐making ability of agents. The model is validated to demonstrate that it can provide practical solutions to natural resource decision making.

Long-term forest management and timely transfer of carbon into wood products help reduce atmospheric carbon

In their efforts to deal with global climate change, scientists and governments have given much attention to the carbon emissions associated with fossil fuels and to strategies for reducing their use. While it is very important to burn less fossil fuel and to employ alternative energy sources, other carbon-reduction options must also be considered. Given that forests comprise a large portion of the global landbase and that they play a very significant role in the global carbon cycle, it is logical to examine how forest management practices could effect reductions in carbon emissions. Many papers that discuss forest carbon sinks or sources refer only to the short term (<20 years). This paper focuses on the sustainable carbon storage contributions of a forest over the long term. This paper explains that long-term carbon storage and reduced carbon fluctuation can be achieved by a combination of improved forest management and efficient transfer of carbon into wood products. Here we show how three different forest management scenarios affect the overall carbon storage capacity of forest and wood products combined over the long term. We used a timber supply model and scenario analysis to predict forest carbon and other resource conditions over time in the Prince George Forest District, a 3.4-million-ha landbase in northern British Columbia. We found that the high-harvest scenario stores 3% more carbon than the low-harvest scenario and 27% (120 million tonnes) more carbon than the no-harvest scenario even though only 1.2-million ha is in timber harvesting landbase. Our results tell us that forest management practices that maintain and increase forest area, reduce natural disturbances in the forest, improve forest conditions, and ensure the appropriate and timely transfer of carbon into wood products lead to increasing overall carbon storage, thereby reducing carbon in the atmosphere.

Defining Transition Rules with Reinforcement Learning for Modeling Land Cover Change

Spatio-temporal modeling provides the opportunity to simulate geographic processes of land use and land cover change (LUCC) by integrating geographic information systems (GIS) with various machine learning approaches to computing. Contemporary models are often developed using a training dataset to define a set of probabilistic transition rules that govern how a landscape changes over time. However, the use of training datasets can be problematic for spatio-temporal modeling, as they can limit the ability to incorporate system complexity and hinder the transferability of the model to different datasets. The purpose of this study is to evaluate a machine learning approach called reinforcement learning (RL) for defining transition rules for GIS-based models of land cover change due to natural resource extraction. Specifically, RL is evaluated based on its potential for constructing models independent of training datasets that can handle different levels of complexity and be transferred across different spatial extents. An RL model for Land Cover Change (RL-LCC) is developed for considering economic and ecological goals involved in natural resource management, and implemented using a hypothetical forest management scenario. Simulation results reveal that agents in the RL-LCC model are able to develop transition rules from their experience in their landscape in a variety of simulation scenarios that allow them to achieve their goals. This study demonstrates the benefits of integrating RL and GIS in order to address important issues of space, time and complexity.

Modeling the effects of alternative management strategies on forest carbon in the Nothofagus forests of Tierra del Fuego, Chile

The impact of forest management activities on the ability of forest ecosystems to sequester and store atmospheric carbon is of increasing scientific and social concern. The nature of these impacts varies among forest ecosystems, and spatially and temporally explicit ecosystem models are useful for quantifying the impacts of a number of alternative management regimes for the same forest landscape. The LANDIS-II forest dynamics simulation model is used to quantify changes to the live overstory and coarse woody debris pools under several forest management scenarios in a high-latitude South American forest landscape dominated by two species of southern beech, Nothofagus betuloides and N. pumilio. Both harvest type (clearcutting vs. partial overstory retention) and rotation length (100 years vs. 200 years) were significant predictors of carbon storage in the simulation models. The prompt regeneration of harvest units greatly enhanced carbon storage in clearcutting scenarios. The woody debris pool was particularly sensitive to both harvest type and rotation length, with large decreases noted under short rotation clearcutting. The roles of extended rotations and partial overstory retention are noted for enhancing net carbon storage on the forest landscape.

Stand-replacing windthrow in the boreal forests of eastern Quebec

The frequency of stand-replacing windthrow has rarely been evaluated over large spatio-temporal scales in boreal forests. This study examines stand-replacing windthrow that occurred within a forested area of 3 061 000 ha, both at the regional scale and at the scale of individual windthrow events. We specifically examined windthrow that covered at least 5 ha and for which mortality affected &gt;75% of pre-windthrow canopy cover. At the regional scale, we found that windthrow affected, on average, 0.0255% of the area per year between 1971 and 2000. Logistic regressions indicate that stand age was the most important predictor variable at this scale, with severe windthrow less likely to occur in relatively young stands (&lt;75 years). At the scale of individual windthrow events, slope direction was the most important predictor variable, with slopes facing the wind affected more. However, this factor was not significant at the regional scale probably because wind direction varied from one windthrow event to another. Overall, our results suggest that stand-replacing windthrow is difficult to predict and integrate into regional-scale forest management scenarios because it is primarily associated with the random occurrence of exceptional windstorms, while other biotic and abiotic variables play a relatively marginal role.

Effects of presenting forest simulation results on the forest values and attitudes of forestry professionals and other forest users in Central Labrador

This research tested whether demonstration of the long term effect of different forest management scenarios in a large forested area changes people's forest values and attitudes. Forestry professionals and other forest users in Central Labrador were shown simulation results of three alternative forest management scenarios illustrating possible long term effects on various indicators. Forest values and attitudes towards forestry were measured before and after the presentation. Our conception of values and attitudes is based on the cognitive hierarchy model of human behaviour which states that values are more enduring and more difficult to change than attitudes. It was thus hypothesized that attitudes would change but not values and that change in forestry professionals would be less than in other forest users since foresters are trained to think about long-term effects and large-scale processes of forest management scenarios. We also hypothesized that a greater number of people would have an opinion on forest management after the presentation. All three hypotheses were partially supported by the results. The results indicated that some attitude change occurred, but that values also changed somewhat. Most of the significant changes occurred when persons with no clear opinion on several forest-related questions formed an opinion. Long-term, landscape simulation results provide valuable information and enhance understanding of both forestry professionals and other forest users. However, being provided the same information, the two groups learned different things. While forest users gained more confidence in the current forest management plan and were motivated to further participate, professionals learned more specific things. This reflects differences between technical and local knowledge.