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Modulus of elasticity (E) is an important property in plantation grown softwoods that describes resistance of timber to deformation under load and is a key criterion in machine stress grading. This paper presents an accurate (R2 = 0.96) site-level model of E for radiata pine (Pinus radiata D. Don) that is applicable across a wide range of tree ages and broad environmental gradients and sensitive to a wide variation in stand density. In the final model, E increased sigmoidally with age and increased linearly with both stem slenderness (height/diameter at 1.4 m) and mean minimum autumn air temperature. For a given age, the model shows stem slenderness to be the main determinant of environmental variation in E, with variation in E ranging approximately 10 GPa across the range in slenderness. Given the simple formulation, this model could be readily used by managers to gain greater understanding of how they can manipulate stands to achieve desired end-use products and maximize crop value. Further research should extend the developed framework so that it can be used to account for intratree, intertree, and clonal variation in E. [ABSTRACT FROM AUTHOR]

As many insect outbreak reconstructions are typically based on targeted single-site sampling, researchers have often been limited in their ability to draw conclusions about regional trends as opposed to local trends in the data. The results of this paper demonstrate the value of a systematic sampling design when studying spatio-temporal processes that can vary greatly within large continuous areas of forest. Many single-site research programs have been conducted to reconstruct the history of larch sawfly (Pristiphora erichsonii Htg.) outbreaks in the eastern boreal region of North America. However, no such research has yet been conducted in the region of Labrador. In an attempt to illustrate the strength of a systematic gridded sampling protocol over a single-site study, we sampled a 12-site grid in western Labrador. Dominant and codominant species were sampled at each grid point, resulting in 24 master chronologies. Six eastern larch (Larix laricina (Du Roi) K. Koch) chronologies (host) and a regional black spruce (Picea mariana (Mill.) Britton, Sterns, Poggenb.) chronology (nonhost) were used to establish a host–nonhost analysis of past sawfly outbreaks on a regional scale. Both regional and localized larch sawfly outbreaks were identified, but in general, larch sawfly outbreaks in western Labrador appeared to be spatially synchronous and regional in scale. [ABSTRACT FROM AUTHOR]

This paper assesses the resilience of Alaska's boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska's boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social-ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities. [ABSTRACT FROM AUTHOR]

This paper outlines molecular analyses of soil fungi within the Bonanza Creek Long Term Ecological Research program. We examined community structure in three studies in mixed upland, black spruce (Picea mariana (Mill.) BSP), and white spruce (Picea glauca (Moench) Voss) forests and examined taxa involved in cellulose degradation at one upland site. We found that soil horizon was the factor by which fungal communities were most strongly structured and that predictable turnover in upland fungal species occurred through succession. Communities from consecutive summers were not significantly different, indicating that interannual variation was small in relation to differences between forest types and soil horizons, yet the community at a seasonal study site underwent significant changes within a year. In each study, mycorrhizal fungi dominated the community. Fungi rather than bacteria appeared to dominate [13C]cellulose degradation, with strongest growth in taxa that were not dominant members of the untreated community, including members of the genus Sebacina. Overall, our results point to considerable interannual resilience juxtaposed with narrow niche partitioning and the capacity of individual taxa in these hyperdiverse communities to respond strongly to resource inputs and changes in other abiotic environmental parameters such as temperature. Our data double the cumulative total of fungal sequences in GenBank and together achieve a better picture of fungal communities here than for any other ecosystem on earth at this time. [ABSTRACT FROM AUTHOR]

This paper integrates dendrochronological, demographic, and experimental perspectives to improve understanding of the response of white spruce (Picea glauca (Moench) Voss) tree growth to climatic variability in interior Alaska. The dendrochronological analyses indicate that climate warming has led to widespread declines in white spruce growth throughout interior Alaska that have become more prevalent during the 20th century. Similarly, demographic studies show that white spruce tree growth is substantially limited by soil moisture availability in both mid- and late-successional stands. Interannual variability in tree growth among stands within a landscape exhibits greater synchrony than does growth of trees that occupy different landscapes, which agrees with dendrochronological findings that the responses depend on landscape position and prevailing climate. In contrast, the results from 18 years of a summer moisture limitation experiment showed that growth in midsuccessional upland stands was unaffected by moisture limitation and that moisture limitation decreased white spruce growth in floodplain stands where it was expected that growth would be less vulnerable because of tree access to river water. Taken together, the evidence from the different perspectives analyzed in this study clearly indicates that white spruce tree growth in interior Alaska is vulnerable to the effects of warming on plant water balance. [ABSTRACT FROM AUTHOR]

We investigated the genetic control of wood properties as a function of cambial age to enable improvement of juvenile wood attributes in white spruce (Picea glauca (Moench) Voss). Increment cores were taken from 375 trees randomly selected from 25 open-pollinated families in a provenance–progeny trial repeated on three sites. High-resolution pith-to-bark profiles were obtained for microfibril angle (MFA), modulus of elasticity (MOE), wood density, tracheid diameter and cell wall thickness, fibre coarseness, and specific fibre surface with the SilviScan technology. Heritability estimates indicated that genetic control of cell anatomy traits and wood density increased with cambial age, whereas the genetic control of MFA and MOE remained relatively low across growth rings. Wood density, radial cell diameter, cell wall thickness, and specific fibre surface were highly heritable, indicating that significant genetic gains could be expected in tree improvement programs, although cambial age at selection may strongly influence the magnitude of realized gains. In contrast, growth-related properties, such as ring width, core length, and tree height, gave weak or nonsignificant heritability estimates. Adverse correlations between mechanical strength and properties related to paper quality suggest that breeding strategies must incorporate both types of traits to improve white spruce wood quality for different end uses. Le contrôle génétique des propriétés du bois selon l’âge cambial a été étudié dans le but d’évaluer la possibilité d’améliorer les attributs du bois juvénile chez l’épinette blanche (Picea glauca (Moench) Voss). Des carottes ont été extraites de 375 arbres choisis aléatoirement parmi 25 familles en pollinisation libre dans un test de provenance-descendances répété sur trois stations. Des profils à haute résolution allant de la moelle à l’écorce ont été obtenus pour l’angle de microfibrilles de cellulose (AMF), le module d’élasticité (MOE), la densité du bois, le diamètre des trachéides, l’épaisseur des parois, la masse linéique et la surface spécifique des cellules, au moyen de la technologie SilviScan. Les héritabilités estimées indiquent que le contrôle génétique des caractéristiques d’anatomie cellulaire augmentent avec l’âge cambial, tandis que le contrôle génétique du MOE et de l’AMF est constant et plus faible que ce qui a été rapporté précédemment chez d’autres conifères. La densité du bois, le diamètre radial, l’épaisseur des parois cellulaires et la surface spécifique étant fortement héritables, des gains importants sont anticipés par le biais de programmes d’amélioration génétique. Toutefois l’âge cambial lors de la sélection pourrait grandement influencer les gains réalisés. À l’opposé, l’héritabilité des caractères de croissance comme la largeur des cernes, la longueur des carottes ou la hauteur de l’arbre était faible ou négligeable. Des corrélations défavorables entre des propriétés mécaniques et des propriétés anatomiques liées à la qualité de la pâte à papier indiquent que l’amélioration de la qualité du bois doit tenir compte des deux types de caractères en fonction de différentes utilisations. [ABSTRACT FROM AUTHOR]

The boreal forest of higher latitudes constitutes a reservoir of trees of great ecological importance and unknown economic potential, but the stand dynamics in these regions still remain essentially unexplored. This paper examines the change in age and size structures during stand development on the northern border of the natural closed boreal forest in Quebec, Canada. Height, diameter, and age of trees were measured in 18 plots with stand ages between 77 and 340 years. The occurrence, size, and origin (layer or seed) of seedlings and saplings were assessed in subplots. Tree density ranged from 600 to 3750 trees·ha–1. Picea mariana (Mill.) BSP was the dominant species, mainly originating by layering. A cluster analysis segregated plots into even-aged and uneven-aged stands according to tree age, but size distribution of trees, saplings, and seedlings did not differ statistically between the two groups. Even-aged stands exhibited a 60% probability of assuming an uneven-aged structure between 120 and 200 years after stand initiation. At high latitudes, the closed boreal forest of P. mariana appears homogeneously sized, with similar distributions of diameter and height across all stages of stand development. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to evaluate whether future climate change would trigger an increase in the fire activity of the Waswanipi area, central Quebec. First, we used regression analyses to model the historical (1973–2002) link between weather conditions and fire activity. Then, we calculated Fire Weather Index system components using 1961–2100 daily weather variables from the Canadian Regional Climate Model for the A2 climate change scenario. We tested linear trends in 1961–2100 fire activity and calculated rates of change in fire activity between 1975–2005, 2030–2060, and 2070–2100. Our results suggest that the August fire risk would double (+110%) for 2100, while the May fire risk would slightly decrease (–20%), moving the fire season peak later in the season. Future climate change would trigger weather conditions more favourable to forest fires and a slight increase in regional fire activity (+7%). While considering this long-term increase, interannual variations of fire activity remain a major challenge for the development of sustainable forest management. [ABSTRACT FROM AUTHOR]

Neonectria fuckeliana (C. Booth) Castl. & Rossman is known to be associated with a stem canker disease of Pinus radiata D. Don in New Zealand plantation forests. Although N. fuckeliana has been previously recorded as a wound invader or weak pathogen of Picea and Abies species in the Northern Hemisphere, little is currently known about the basic biology of the fungus. This paper outlines early investigations into the spore production and dispersal of N. fuckeliana in New Zealand. Perithecia of N. fuckeliana occur frequently on pruned stubs and on the surface of cankers, and ascospores appear to be the primary means of dispersal for this fungus in New Zealand. Both field collections and spore trapping show that mature perithecia contain viable ascospores in all seasons, and spores are ejected and dispersed using moisture. The conidial phases are rarely found in the field. Optimum temperature for both growth of mycelium and ascospore germination was between 15 and 25 °C. Some spore germination occurred at temperatures as low as 5 °C, but above 25 °C spore germination was abnormal. Ascospores and perithecia favoured storage in lower temperatures: overall, ascospores from perithecia stored at room temperature gradually lost their viability, whereas those stored at 4 and –8 °C maintained their viability over an 18 month period. [ABSTRACT FROM AUTHOR]

Vertical and horizontal patterns of light within gaps and expansion of trees into gaps were examined in young stands dominated by trembling aspen (Populus tremuloides Michx.) in northeastern British Columbia and northwestern Alberta. Lateral growth of branches of aspen edge trees averaged 15.2 cm/year and was similar to crown expansion rates reported for edge trees in eastern North America. Branches growing into gaps were significantly longer than those growing away from gaps and are likely to lead to gap shrinkage and reductions in light within gaps. However, height growth of edge trees was not significantly different from that of trees within the surrounding stands. Models describing relationships between diffuse transmittance and locations within gaps and surrounding stand height were developed in this paper. Sky view angle (SVA) was found to be effective for predicting transmittance to different locations within gaps. When SVA values exceed 1.2 (at the B.C. sites), white spruce (Picea glauca (Moench) Voss) will receive <40% of full sunlight, which is less than optimal for spruce height growth. [ABSTRACT FROM AUTHOR]

This paper describes the development and implementation of Cambium, an agent-based forest sector model for strategic analysis. This model is designed as a decision-support tool for assessing the effects that changes in product demand and resource inventories can have on the structure and economic viability of the forest sector. Cambium models aggregate product supply as an emergent property of individual companies’ production decisions and stand-level ecological processes. Modeling the forest-products sector as a group of interacting autonomous economic agents makes it possible to include production capacity dynamics and the potential for mill insolvencies as factors in analyzing the effects of market and forest inventory based disturbances. The utility of this model is tested by assessing the impacts of a market downturn in the US forest products market on forest industry structure and mountain pine beetle (Dendroctonus ponderosae Hopkins) salvage harvesting in British Columbia, Canada. Simulation results indicate a significant medium-term timber supply shortage; reduced stumpage revenues; intensive cost competition among primary wood-products manufacturers; and a large number of insolvencies in the panel, lumber, and pulp sectors. [ABSTRACT FROM AUTHOR]

Modelling volumes by log grades in standing hardwood trees is often hindered by the nature of the response variable. In this paper, we used a two-part conditional model to account for the excess of zero responses for some log grades. Moreover, this approach was used as a framework to compare three different tree classifications in their ability to predict volumes by log grades in standing yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer saccharum Marsh.) trees. A tree grade classification was compared with two preharvest tree classifications based on mortality risk assessment. A cross-validation was also carried out to evaluate the two parts of the model. The results showed that the two-part conditional approach was efficient in this case study. Compared with a general model, the three classifications improved the maximum likelihood. According to the Akaike and Bayesian information criteria, the tree grade classification was the “best” one. All three classifications proved to be better able to distinguish log grade occurrence than log grade volume. Although it implies additional cost, the implementation of the tree grade classification into the preharvest inventories would improve the prediction of volumes by log grades for yellow birch and sugar maple trees. [ABSTRACT FROM AUTHOR]

Quantitative decision analysis and respective planning models offer many benefits in forest planning. They are efficient, quick, inexpensive, objective, and repeatable. However, quantitative planning and the respective planning models also include many sources of uncertainty. In this paper our research objective is to analyse decision makers’ preferential uncertainty in the context of multicriteria forestry decision making by using statistical models for so-called interval-scale continuous decision problems. The models are based on 0–1-type utility functions by applying a Finnish school grading system for collecting the preference data. The basic idea is to assess the preferences at some discrete points and then estimate the continuous priority function according to the statistical estimation techniques. An interactive approach for reducing the preferential uncertainty included in the priority model is also developed. In the interactive step, the improvements of the priority model are based on uncertainty measures related to local and (or) global priority models. The role of statistical uncertainty analysis is to make the interactive planning process more efficient and reliable. The interactive and statistical approaches complement each other and promote decision makers’ learning. [ABSTRACT FROM AUTHOR]

Dumping has been one of the most controversial issues in the never-ending softwood lumber trade dispute between the United States (US) and Canada. In this paper, we investigate whether the softwood lumber producers in Ontario dumped product into their major market in the US during the period from April 1996 to September 2006. The Enhanced Parity Bounds Model was used to explore the possibility that Ontario’s softwood lumber producers had exercised price discrimination between the Toronto market and the Great Lakes market. Our analysis indicates that the industry had on average charged a higher price in the Great Lakes market than in the Toronto market during this period. Based on this evidence and the economic conditions in which a US antidumping investigation and two administrative reviews were conducted, we draw the conclusion that the Ontario’s softwood lumber producers did not dump product into the US market during the study period. [ABSTRACT FROM AUTHOR]

This paper presents soil fluxes of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) from 12 sites located in four major forest types, black spruce (Picea mariana (Mill.) BSP), jack pine (Pinus banksiana Lamb.), aspen (Populus spp.), and alder (Alnus spp.) stands, in the Eastmain and Chibougamau regions of Quebec. Fluxes were determined with closed chambers during the snow-free period from May to October 2007. Well-drained black spruce, jack pine, and aspen forest soils were net sinks of atmospheric CH4 (–0.33 ± 0.11 mg·m–2·day–1), while alder-dominated wetland soils were sources of CH4 (0.45 ± 0.12 mg·m–2·day–1). The cut-over alder wetland soil produced 131 times more CH4 than the undisturbed wetland soil. Soil moisture and temperature mainly regulated CH4 fluxes. N2O fluxes from these forest soils were highly variable and smaller (1.6 ± 0.33 µg N·m–2·h–1) than those from deciduous forest soils. N2O emission from the cut-over black spruce forest soil was 2.7 times greater than that from the mature black spruce forest soil. Large C/N ratios (27 to 78) and slow soil N mineralization and nitrification rates in these forest soils may have led to small N2O fluxes. CO2 emissions from these forest soils, ranging from 0.20 to 2.7 g·m–2·day–1, were mainly controlled by soil temperature. [ABSTRACT FROM AUTHOR]

Harvest scheduling decisions are made in an uncertain environment, and current modeling techniques that consider uncertainty impose severe difficulties when solving real problems. In this paper we describe a robust optimization methodology that explicitly considers randomness in most of the model coefficients while keeping the model computationally tractable. We apply the method to schedule harvest decisions when both timber yield and demand of two products are uncertain. Since uncertain coefficients must be independent, uniform, and symmetrically distributed, we only address uncertainty attributable to estimate errors of forecast models. The methodology was applied to a 245 090 ha forest in British Columbia, Canada. We compared the change in harvest decisions and objective function when robust solutions are implemented relative to deterministic solutions. Although probability bounds can be used to a priori define the probability of constraint violations, they produce conservative solutions. We therefore tested the rates of constraint violations by simulation. While traditional deterministic decisions were always infeasible when uncertain data were simulated, robust decisions were much less sensitive to uncertainty and were, to a large extent, protected against the occurrence of infeasibilities. In exchange, reasonable reductions in the objective function were observed. [ABSTRACT FROM AUTHOR]

The paper studied the short-term effects of experimental warming, nitrogen fertilization, and their combination on growth and photosynthetic performances of Picea asperata Mast. and Pinus tabulaeformis Carr. seedlings. These seedlings were subjected to two levels of temperature (ambient temperature and infrared heater warming) and two nitrogen levels (0 and 25 g N·m–2·year–1) for 6 months. Warming alone and fertilization alone significantly increased biomass accumulation and photosynthetic performances of both two species. The combination of warming and fertilization stimulated greater accumulation of stem, root, and total biomass and further increased chlorophyll content and net photosynthesis rate (A) in Pinus tabulaeformis seedlings. However, for Picea asperata seedlings, the interaction induced less increment in plant height, total biomass, chlorophyll contents, A, and the efficiency of photosystem than nitrogen treatment alone. These results implied that both climate warming and nitrogen addition were favorable for the early growth of both coniferous species; the interaction of these two factors caused adding or multiplying single-factor effects in the case of Pinus tabulaeformis seedlings but dampening them in the case of Picea asperata seedlings, at least in short time. [ABSTRACT FROM AUTHOR]

The Fire and Fire Surrogates (FFS) network is composed of 12 forest sites that span the continental United States, all of which historically had frequent low-severity fire. The goal of the FFS study was to assess the efficacy of three management treatments (prescribed fire, mechanical thinning, and their combination) in reducing wildfire hazard and increasing ecosystem sustainability. This paper describes the impact of the FFS treatments on nitrogen (N) storage and distribution. At the network scale, total ecosystem N averaged 4480 kg·ha–1, with ~9% in vegetation, ~9% in forest floor, ~2% in deadwood, and ~80% in soil. The loss of vegetation N to fire averaged (±SE) 25 ±11 kg·ha–1, whereas the mechanical and combined mechanical and fire treatments resulted in N losses of 133 ±21 and 145 ±19 kg·ha–1, respectively. Western coniferous forests lost more N from each treatment than did eastern forests. None of the manipulative FFS treatments impacted >10%–15% of total N of these ecosystems. Management strategies that maximize ecosystem carbon (C) gain by minimizing loss of N should be a focus in western forests, where C and N cycling are tightly linked, but perhaps not in those eastern forests where atmospheric N deposition has decoupled C and N cycles. [ABSTRACT FROM AUTHOR]

The expected opportunity costs of conserving a specific land use are usually considered adequate as financial compensation. However, a “conservation premium” is sometimes proposed as an added incentive, i.e., compensation greater than the expected opportunity costs. This paper discusses various methodological opportunities for deriving effective compensation under uncertainty. Based on cumulative distribution functions of possible opportunity costs (a Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation was considered the alternative to conserving a Chilean secondary forest), generated through Monte Carlo simulations, we derived an inclusive range of possible compensations from 77 up to 375 US$·ha–1·year–1. If we assumed that the two land-use alternatives were mutually exclusive and independent from other risky investments, a compensation of 375 US$·ha–1·year–1 was necessary to convince every decision maker to maintain the secondary forest. However, only 77 US$·ha–1·year–1 was enough for a risk-averse decision maker (given average opportunity costs of 113 US$·ha–1·year–1). Yet, it turned out that the greatest possible opportunity costs would already be compensated for with 199 US$·ha–1·year–1, given an error probability of 0.05. Compensating for the last 5% of possible opportunity costs would thus require an additional 176 US$·ha–1·year–1. Our approach had two main limitations, namely we did not consider portfolio effects, which would allow diversifying away unsystematic risks, and we did not take into account the different systematic risks of the compared alternatives. These limitations may have led to an overestimation of effective compensation. [ABSTRACT FROM AUTHOR]

In this paper, we extend traditional methods of spatial statistics to study spatiotemporal correlations between two different point processes. After introducing the methodology, we apply this analysis to a particular case study of interest in ecology, the interaction between damage by a particular forest pest (western spruce budworm (Choristoneura occidentalis)) and forest fires. Our analysis, which covers parts of British Columbia in the 26-year period from 1970 to 1995, indicates that areas affected by budworm infestation have a significantly decreased risk of forest fire for the 7 years following the infestation. Conversely, forest fires decrease the risk of infestation for at least 6 years after the fire. These temporal correlations extend over a spatial range of at least 25 km. Our study rejects the common assumption that insect infestation necessarily results in increased fire risk. This case study illustrates the utility of point process modeling and spatial statistics to understanding ecosystem dynamics extending over both space and time. [ABSTRACT FROM AUTHOR]

It is critical to understand how the public prioritizes multiple forestry values when establishing objectives for sustainable forest management. While this is a complex and difficult task, a necessary step is to elicit a broad range of public opinions in forest planning to ensure that decisions serve the needs of various forest stakeholders and society at large. This study seeks to understand how six forest dependent communities in British Columbia prioritize a number of attributes associated with sustainable forest management by using a simple survey-based measurement tool, the Thurstone scale. The results suggest that ecological attributes are a higher priority for survey respondents followed by quality of life, global warming, and economic considerations. This paper explores some of the ramifications of the priorities for sustainable forest management measured in these six communities as well as implications for using the Thurstone scale in processes like Public Advisory Groups. [ABSTRACT FROM AUTHOR]

This paper uses data envelopment analysis (DEA) to characterize the changing production frontier (technical efficiency, productivity growth, technical and efficiency change, and returns to scale) of the sawmilling industry in the Pacific Northwest (PNW) US using geographical panel data for the period 1968–2002. Unlike past DEA studies, we develop confidence intervals for all estimates using an improved bootstrapping method. The results indicate that the gap between the least and most efficient regions in PNW has grown and the least efficient regions are falling further behind the most efficient regions. For the Oregon regions, the null hypothesis of constant returns to scale (CRS) could not be rejected for any year. For the Washington regions, returns to scale varied year by year, although only two of the five regions showed strong tendencies away from CRS. For PNW as a whole, mean productivity growth was 0.5% per year between 1968 and 1992. Between 1992 and 2002, the regional mean was 1.3%, although with wide variation across regions. DEA results indicate that the vast majority of productivity growth in the PNW sawmilling industry between 1968 and 2002 was due to technical change. Improvements in scale efficiency played a very small role, and efficiency change was zero or negative. [ABSTRACT FROM AUTHOR]

Understory light is essential to the establishment and growth of understory plants and varies temporally and spatially within gaps. The previously defined gap light index (GLI) is a good model for assessing understory light levels, but it is time-consuming to determine gap coordinates, which are crucial to GLI, for numerous points within a gap. This paper introduces the geometric calculation (GeoCalc) of gap coordinates. GeoCalc quickly obtains gap coordinates for any specified point within a canopy gap and takes into account the tridimensional profile of the gap and the slope and aspect of the ground. The GeoCalc-based GLI was validated by the GLI derived from hemispherical photographs taken at 93 sampling points within seven natural gaps. Our results demonstrate that GeoCalc-based GLI was strongly positively correlated and not significantly differed from the GLI derived from hemispherical photographs. Next, to analyze gap light regimes and the effects of gap size, canopy height, and topography, three natural gaps of various size were selected and simulated as nine gaps with 1 and 1.5 times canopy height or on the opposite slope. Finally, we have summarized characteristics of GeoCalc-based GLI and its application. [ABSTRACT FROM AUTHOR]

Angle count or relascope sampling has traditionally been used in forestry to estimate stand basal area. In this paper, we present an extension to the basal area relascope, the crown relascope, which differs from the normal relascope in that the relascope’s slot is very high and wide. We describe the theoretical basis of the instrument and present results from a field test in which a crown relascope with a basal area factor of 250 m2/ha (0.025) was used to estimate canopy cover of 73 sample plots in northern Finland. The crown relascope estimates had a root mean square difference of 9.3% and an average difference of –3.1% when compared with estimates obtained with the control method, line intersect sampling using the Cajanus tube. The results indicated that the crown relascope is a quick and fairly reliable instrument for canopy cover estimation, especially in relatively sparse forests where crown overlap is insignificant and visibility does not limit an efficient use of the instrument. [ABSTRACT FROM AUTHOR]

Growth and form are the two main traits used for genetic improvement of maritime pine (Pinus pinaster Ait.) in the southwest of France. In this paper, wood density is studied to answer two main questions: Is there a general trend for density variability throughout tree development and has selection indirectly reduced wood density variability over breeding populations, owing to genetic unfavourable correlation with growth? Wood density and its components were studied in three polycross tests, each representative of one of the successive breeding populations. Wood density was measured with an X-ray densitometer in approximately 50 families per test with >1900 trees. A preliminary study showed that bark-to-pith ring indexing allows for a better estimation of genetic effects than does pith-to-bark indexing. Genetic variability of wood density appears to be highly dependent on the year considered and no general pattern can be detected over time. Whereas the variability of selected traits is known to have decreased over breeding populations, no significant change was found for variability of wood density. [ABSTRACT FROM AUTHOR]

This paper examines the problem of harvest capacity planning at a tactical level. Annual capacity planning allows planners to determine the number of contractors to hire per period throughout the year and to define the duration of their contracts. In practice, this process usually involves the analysis of historical data regarding the operational use of capacity and aggregated demand forecast, the output of which then serves to plan harvest operations. Although this form of hierarchical planning reduces the complexity of the task, the decomposition into subproblems that must be successively resolved can lead to infeasibility or poor use of harvesting capacity. The specific problem addressed here resides in how one can consider the operational impact of harvesting decisions taken at the tactical level to ensure a plan’s feasibility at the operational level. We present a tactical planning process based on Schneeweiss’ generic hierarchical modeling approach. A computational experiment demonstrates how a tactical planning process is influenced by the input of the operational level anticipation model. The anticipation approach we propose appears to be a valid method to better integrate key operational-level decisions into tactical plans. [ABSTRACT FROM AUTHOR]

The mechanisms governing tree mortality in surface fires are poorly understood, owing in large part to the absence of a process-based framework for defining and evaluating these mechanisms. This paper begins the development of such a framework by deriving a first-order process model of tree mortality in surface fires (intensities less than approximately 2500 kW·m–1). A buoyant line-source plume model is used to drive heat transfer models of vascular cambium and vegetative bud necroses, which are linked to tree mortality using an allometrically-based sapwood area budget. Model predictions are illustrated for white spruce (Picea glauca), lodgepole pine (Pinus contorta), and trembling aspen (Populus tremuloides) and are compared with independent mortality data for Engelmann spruce (Picea engelmannii Parry ex Engelm.) and Pinus contorta Dougl. Results help define first-order mortality mechanisms and suggest second-order mortality mechanisms that should be incorporated into future modeling efforts. Les mécanismes qui régissent la mortalité des arbres à la suite d’un feu de surface sont peu connus, surtout à cause de l’absence de cadre théorique basé sur les processus permettant de définir et d’évaluer ces mécanismes. Cet article jette les bases d’un tel cadre théorique en dérivant un modèle de premier ordre de mortalité des arbres basé sur les processus à la suite d’un feu de surface (intensité inférieure à environ 2500 kW·m–1). Un modèle de panache flottant dont la source est linéaire est utilisé pour faire fonctionner des modèles de transfert de chaleur du cambium vasculaire et de nécrose des bourgeons foliaires, laquelle est reliée à la mortalité des arbres grâce à un bilan de surface d’aubier basé sur des relations allométriques. Les prédictions du modèle sont illustrées pour l’épinette blanche (Picea glauca), le pin tordu (Pinus contorta), et le peuplier faux-tremble (Populus tremuloides) et sont comparées à des données indépendantes de mortalité pour le l’épinette d’Engelmann (Picea engelmannii Parry ex Engelm.) et Pinus contorta Dougl. Les résultats aident à définir les mécanismes de premier ordre et à suggérer des mécanismes de second ordre à l’origine de la mortalité. Ces mécanismes devraient être retenus lors de tentatives futures de modélisation. [ABSTRACT FROM AUTHOR]

This paper examined the impact of commercial thinning on selected wood properties of jack pine (Pinus banksiana Lamb.). Wood properties evaluated include wood density (ring density, earlywood ring density, and latewood ring density), percentage of latewood in the ring, and wood bending properties. Nonlinear, mixed-effect models have been developed using data from three commercially thinned sites in eastern Canada. Ring density followed the same pattern as percentage of latewood, in which cambial age, relative height, and ring width were found to have important effects. Earlywood and latewood ring densities changed within the juvenile wood zone until a plateau was reached. Ring width affected earlywood and latewood ring densities mainly in narrow rings. Wood bending stiffness (measured by modulus of elasticity) and strength (measured by modulus of rupture) increased with cambial age and wood density; whereas, wood strength was also affected by ring width. Commercial thinning did not influence the developed models, but it had an indirect effect through increased ring width. Cette étude a examiné l’impact de l’éclaircie commerciale sur certaines propriétés du bois de pin gris (Pinus banksiana Lamb.). Ces propriétés incluaient la densité du bois (densité des cernes, densité du bois initial et densité du bois final), la proportion de bois final dans chaque cerne et les propriétés mécaniques en flexion. Des modèles non linéaires mixtes ont été développés à partir de données provenant de trois stations qui avaient subi une éclaircie commerciale dans l’est du Canada. La densité des cernes s’est révélée être fortement influencée par l’âge cambial, la hauteur relative et la largeur des cernes, suivant ainsi un patron de variation similaire à celui de la proportion de bois final. La densité du bois initial et celle du bois final ont changé à l’intérieur de la zone de bois juvénile pour atteindre un plateau par la suite. La largeur des cernes a aussi affecté ces densités, en particulier dans le cas des cernes étroits. Les modules d’élasticité (MOE) et de rupture (MOR) en flexion ont augmenté avec l’âge cambial et la densité du bois. De plus, le module de rupture a été affecté par la largeur des cernes. L’éclaircie commerciale n’a pas changé les paramètres des modèles, mais elle a eu une influence indirecte à cause de son effet sur la largeur des cernes. [ABSTRACT FROM AUTHOR]

Herbivorous insect infestations significantly alter element and nutrient cycling in forests, thus directly and indirectly affecting ecosystem functioning. In this paper, we report on the herbivore-mediated transfer of carbon (C) and nitrogen (N) from the canopy to the forest floor and its influence on soil microbial activity during a pine lappet (Dendrolimus pini L.) infestation. Over the course of 6 months, we followed C and N fluxes in bulk deposition, throughfall, and green fall (green needle debris dropped during herbivory) together with solid frass (insect faeces) in an 80-year-old Scots pine (Pinus silvestris L.) forest. Compared with the control, herbivore defoliation significantly doubled throughfall inputs of total and dissolved organic C and N over the study period. Frass plus green-fall C and N fluxes peaked in June–July at 110 kg C·ha–1 and 2.3 kg N·ha–1, respectively. Randomized intervention analysis revealed no significant effects of herbivory on soil microbial properties, except for adenylate energy charge, which showed slightly higher values under herbivory. This study demonstrates the importance of canopy herbivory on overall C and N inputs to forest ecosystems, particularly in altering the timing and quality of the organic material reaching the forest floor and potentially affecting belowground processes. Les infestations d’insectes herbivores modifient de façon significative le recyclage des éléments et des nutriments dans les forêts, affectant ainsi directement et indirectement le fonctionnement de l’écosystème. Cet article traite du transfert, résultant de l’action des herbivores, du carbone (C) et de l’azote (N) de la canopée vers la couverture morte et de son influence sur l’activité microbienne dans le sol au cours d’une infestation du bombyx du pin (Dendrolinus pini L.). Sur une période de 6 mois, nous avons suivi les flux de C et N dans les dépôts bruts, la précipitation au sol et la chute de litière vivante (débris d’aiguilles vivantes tombées au sol en lien avec l’herbivorisme) ainsi que les excréments d’insectes dans une forêt de pin sylvestre (Pinus silvestris L.) âgée de 80 ans. Contrairement au témoin, la défoliation causée par les herbivores a doublé les apports de N et de C organique totaux et dissous dans la précipitation au sol pendant la période d’étude. Les flux de C et N dans les excréments et la chute de litière verte ont culminé en juin–juillet atteignant 110 kg C·ha–1 et 2,3 kg N·ha–1. L’analyse d’intervention aléatoire n’a révélé aucun effet significatif de l’herbivorisme sur les propriétés microbiennes du sol, à l’exception de la charge énergétique adénylique qui avait une valeur légèrement supérieure à la suite de l’action des herbivores. Cette étude démontre l’importance de l’herbivorisme dans la canopée quant à l’apport global de C et N dans les écosystèmes forestiers, particulièrement en modifiant la qualité de la matière organique qui se retrouve dans la couverture morte et le moment où elle s’y retrouve et en affectant possiblement les processus dans le sol. [ABSTRACT FROM AUTHOR]

Diameter distributions are an important source of information for estimating the timber assortment in forest stands. In this paper, a one-step procedure for deriving the parameters of a Weibull function, itself used to describe diameter distributions, is presented. A generalized linear model (GLM) is employed that allows for an estimation of the shape and scale parameters as functions of different predictors. The GLM was fit using 495 sample plots from a conventional sample-plot inventory. Plotwise height metrics derived from airborne laser scanner data serve as covariates (auxiliary variables). Each sample plot consists of four concentric circle plots, where the largest plot covers an area of 450 m2 (12 m radius). Trees with a diameter at breast height (DBH) <30 cm are measured only on the smaller circle plots. Because of this design, left- and right-truncated Weibull distributions, conditional on the DBH, were used to fit the data. The frequently used two-step procedure — in which the Weibull distribution is firstly fitted via maximum likelihood, and its parameters are then estimated via linear regression — requires an adequate number of observations per sample plot in the first step. Hence, this method would have been unsuitable for the data source at hand, because a mean of just 12 trees per sample plot was recorded. The visual comparison of the predicted Weibull distributions with observed data shows a good fit to the data. The mean of the DBH distributions was estimated with a root mean square error (RMSE) of 2.44 cm and a bias of 0.41 cm. [ABSTRACT FROM AUTHOR]

With increasing concerns about the costs of forest management, there is a need to rigorously evaluate any management activities that add to costs. Certification has been widely adopted at considerable financial cost to those managing forests. Although there have been many studies of the impacts of certification, there is no comprehensive framework for assessing whether or not certification has been effective in achieving its goals. To do this, certification needs to be viewed as a part of an international environmental regime. Using established methodologies, this paper applies an evaluation framework and examines forest certification effectiveness in a number of categories: problem solving, goal attainment, behavioural effectiveness, process effectiveness, constitutive effectiveness, and evaluative effectiveness. It is too early to assess its effectiveness in problem solving and goal attainment. However, forest certification has been quite successful at process and constitutive effectiveness and is now widely recognized by a range of institutions. Its effectiveness in changing behaviours is less clear, and its evaluative effectiveness remains to be determined. [ABSTRACT FROM AUTHOR]

Spatial tree data are required for the development of spatially explicit models and for the estimation of summary statistics such as Ripley’s K function. Such data are rare and expensive to gather. This paper presents an efficient method of synthesizing spatial tree point patterns from nearest neighbour summary statistics (NNSS) sampled in small circular subwindows, which uses a stochastic optimization technique based on simulated annealing and conditional simulation. This nonparametric method was tested by comparing tree point patterns, reconstructed from sample data, with the original woodland patterns of three structurally different tree populations. Analysis and validation show that complex spatial woodland structures, including long-range tree interactions, can be successfully reconstructed from NNSS despite the limited range of the subwindows and statistics. The influence of the NNSS varies depending on the woodland under study. In some cases, the sampling results can be improved by reconstruction. Furthermore, it is clearly shown that it is possible to estimate second-order characteristics such as Ripley’s K function from small circular subwindows through the reconstruction technique. The results offer new opportunities for adding value to woodland surveys by making raw data available for further work such as growth projections, visualization, and modelling. [ABSTRACT FROM AUTHOR]

This paper investigates the impacts of forest taxes within an age-class forest model where the landowner derives utility from both consumption and the amenity values of standing forest. The model generalizes the existing models used to analyze forestry taxes. It is shown how the age-class model enables a more detailed analysis of the substitution and income effects of various taxes. These effects are shown to be linked to the properties of the utility function and to the distribution of the landowner’s assets between forests and nonforest assets. The results indicate that for most utility functions, income effect is unlikely to dominate the substitution effect of taxes on forest owner timber harvesting decisions. Numerical examples are used to demonstrate how the tax impacts can differ in the short run and long run. The results imply that higher consumption levels combined with profit or sales taxation applied in forestry will effectively reinforce each other in increasing optimal rotations. On the other hand, a lump-sum tax may be used to counteract the impact of increasing consumption levels. [ABSTRACT FROM AUTHOR]

Locating fuel treatments with scarce resources is an important consideration in landscape-level fuel management. This paper developed a mixed integer programming (MIP) model for allocating fuel treatments across a landscape based on spatial information for fire ignition risk, conditional probabilities of fire spread between raster cells, fire intensity levels, and values at risk. The fire ignition risk in each raster cell is defined as the probability of fire burning a cell because of the ignition within that cell. The conditional probability that fire would spread between adjacent cells A and B is defined as the probability of a fire spreading into cell B after burning in cell A. This model locates fuel treatments by using a fire risk distribution map calculated through fire simulation models. Fire risk is assumed to accumulate across a landscape following major wind directions and the MIP model locates fuel treatments to efficiently break this pattern of fire risk accumulation. Fuel treatment resources are scarce and such scarcity is introduced through a budget constraint. A test case is designed based on a portion of the landscape (15 552 ha) within the Southern Sierra fire planning unit to demonstrate the data requirements, solution process, and model results. Fuel treatment schedules, based upon single and dual wind directions, are compared. [ABSTRACT FROM AUTHOR]

The management of threatened and endangered species can be improved by understanding their patterns of genetic diversity and structure. This paper presents the results of the first analysis of the population genetics of butternut (Juglans cinerea L.) using nuclear microsatellites. Butternut once was an economically and ecologically valuable hardwood, but now its numbers are rapidly decreasing throughout its native range in eastern North America. By genotyping butternut trees (n = 157) from five populations at seven highly polymorphic loci, we determined that the remaining genetic diversity for the species is considerably higher than previously estimated (mean HE = 0.75). Populations were nearly genetically homogenous (FST = 0.025), with no evidence of isolation by distance. These results indicate that butternut retains a large amount of genetic diversity, and that it is not too late to implement strategies to conserve local butternut populations. [ABSTRACT FROM AUTHOR]

We illustrate effects of competitor spacing for a new class of individual-tree indices of competition that we call semi-distance-independent. This new class is similar to the class of distance-independent indices except that the index is computed independently at each subsampling plot surrounding a subject tree for which growth is to be modelled. We derive the effects of distance for this class as the expected value over independent samples containing a particular subject tree. In a previous paper, we illustrated distance effects implicit in eight indices of the distance-dependent class. Here, we present distance effects of four semi-distance-independent indices: density, sum of diameters, basal area, and tree-area ratio; each determined for small fixed-area plots of 0.04 ha and for Bitterlich samples of 6 m2·ha–1. We show that several members of this new class have distance effects very similar to the distance-dependent class and should, therefore, be equally effective in accounting for competitive effects in individual-tree increment models. The comparisons should inform selection of competition indices and sampling designs for growth modelling. [ABSTRACT FROM AUTHOR]

Coarse woody debris (CWD) is an important structural element in forests. Its role depends on the species, size, position, and decay rate. This paper reports an attempt to determine the total residence time of CWD across all decay classes and also within successive decay classes. We simulated the process of CWD decomposition for stem size and position (snags versus logs), using matrices of the transition of CWD between decay classes. The study was based on a sample of 2785 Norway spruce snags and logs measured twice over a 10  year period in a Carpathian subalpine forest. The revealed pattern of decomposition depended highly on CWD size. When log numbers were considered, the mean total residence time increased from 71 years for small logs (diameter < 23 cm) to 90 years for medium-sized logs (23–35 cm), and to 113 years for large logs (>35 cm). In terms of volume, the mean total residence times of logs were 47, 49, and 63 years for the three diameter categories. Still shorter were the mean total residence times for log mass: 34, 41, and 41 years for the three diameter categories. The pattern of decomposition depended highly on the CWD attributes taken into consideration. The differences in decay rate between log diameter categories are considerable when the number of logs is taken into account, but they practically vanish when log mass is considered. Les débris ligneux grossiers (DLG) constituent un élément structural important dans les forêts. Leur rôle dépend de l’espèce, de la dimension, de la position et du taux de décomposition. Cet article fait état d’une tentative pour déterminer le temps total de résidence des DLG pour l’ensemble des classes de décomposition ainsi que dans les classes de décomposition successives. Nous avons simulé le processus de décomposition des DLG en fonction de leur dimension et de leur position (chicot vs bille au sol) à l’aide de matrices de transition des DLG entre les classes de décomposition. L’étude était basée sur un échantillon de 2785 billes et chicots d’épicéa commun mesurés à deux reprises sur une période de 10 ans dans une forêt subalpine des Carpates. Le patron de décomposition qui a été observé dépendait fortement de la dimension des DLG. Lorsque le nombre de billes au sol était considéré, le temps total moyen de résidence passait de 71 ans pour les petites billes (diamètre < 23 cm) à 90 ans pour les billes de dimension moyenne (23–35 cm) et à 113 ans pour les grosses billes (>35 cm). En terme de volume, le temps total moyen de résidence était de 47, 49 et 63 ans pour les trois catégories de diamètres. Si on considérait la masse des billes au sol, le temps total moyen de résidence était encore plus court, soit 34, 41 et 41 ans pour les trois catégories de diamètres. Le patron de décomposition dépendait fortement des caractéristiques des DLG qui étaient considérées. Les différences dans le taux de décomposition entre les catégories de diamètres sont considérables lorsqu’on tient compte du nombre de billes mais elles disparaissent pratiquement lorsqu’on considère la masse des billes. [ABSTRACT FROM AUTHOR]

This paper uses survey information to examine several common assertions about the institutional prerequisites for successful profitability when a First Nation enters an economic enterprise either independently or in joint effort with an outside firm. In the winter of 2004–2005, we interviewed managers on both the First Nations and private sides of joint ventures and other business alliances in Canada, to determine what affected their recent profitability experience. We gathered information on the ages, sizes, and activities of the firms. We also gathered information about the firms’ management structures and relationship with the First Nation, and the characteristics of the government of the First Nation. With a sample size of 40 firms that responded, we found that several institutional characteristics affected profit positively: strong separation of management from band governance, participation in management planning, and the use of staggered terms in band council elections. We found that the likelihood of profitability decreased if the band had been in third party management as well as if there was formal participation of elders or hereditary chiefs in decision making. We offer interpretations of these results. Cet article utilise les données d’un sondage réalisé au cours de l’hiver 2004–2005 afin d’examiner plusieurs assertions courantes au sujet des préalables institutionnels requis pour atteindre la profitabilité des entreprises initiées par des Premières nations agissant seules ou en partenariat avec des acteurs privés. Nous avons interviewé des gestionnaires impliqués dans de tels partenariats d’affaires au Canada et provenant tant des Premières nations que du secteur privé. Nous voulions déterminer ce qui affectait la profitabilité qu’ils avaient connue récemment. Nous avons rassemblé de l’information sur l’âge, la taille et les activités des entreprises. Nous avons aussi recueilli des données sur la structure de gestion des entreprises, les relations avec les Premières nations et les caractéristiques de la gouvernance en vigueur dans les communautés d’accueil. Un échantillon, regroupant les quarante entreprises qui ont répondu, nous permet d’observer que plusieurs caractéristiques institutionnelles, comme la séparation claire entre la gestion des projets et la gouvernance des communautés, la participation dans la planification managériale et le recours à des mandats échelonnés lors des élections au conseil de bande, affectent positivement les profits. Nous avons aussi remarqué que les chances de profitabilité diminuent si les conseils de bandes jouent un rôle en tant que de tierce partie dans la gestion des entreprises et si les aînés ou les chefs héréditaires participent formellement au processus décisionnel. Nous tentons d’interpréter ces résultats. [ABSTRACT FROM AUTHOR]

This paper presents the 5 year results of different cutting intensities (removal of 0%, 40%, 50%, 60%, and 100% of the basal area) applied in two mixed yellow birch (Betula alleghaniensis Britt.) – conifer stands of eastern Quebec, Canada. Two sites 90 km apart were used: Armagh and Duchesnay. Each site had four replicates of the treatments in a randomized block design. The effect on light availability was similar in the two sites: the 0%, 40%, 50%, 60%, and 100% cuts transmitting a mean of 5%, 21%, 26%, 30%, and 94% of full light, respectively, during the first summer. Soil temperature increased only in the 100% cut (4-5 °C, maximum daily temperature). Soil disturbance during harvest was higher at Duchesnay than at Armagh, which clearly improved seedbed receptivity, particularly to yellow birch. After 5 years, treated areas contained 21 000 to 48 300 seedlings/ha at Duchesnay compared with 5500 – 10 500 seedlings/ha at Armagh. Significant losses of coniferous advance growth were observed at both sites, but a subsequent seedling recruitment occurred only at Duchesnay. Red spruce (Picea rubens Sarg.) showed superior establishment in the 60% cut (4400 seedlings/ha) than under other cutting intensities (1600–2100 seedlings/ha), whereas balsam fir (Abies balsamea (L.) Mill.) responded well to all partial cutting treatments. At both sites, pin cherry (Prunus pensylvanica L.f.) was the main competing species in the 100% cut, whereas densities of the preestablished mountain maple (Acer spicatum Lamb.) and striped maple (Acer pensylvanicum L.) either remained the same or increased in the partial cuts. Cet article présente les résultats de 5 ans de différentes intensités de coupe (prélèvements de 0 %, 40 %, 50 %, 60 % et 100 % de la surface terrière) appliquées dans deux peuplements mixtes de bouleau jaune (Betula alleghaniensis Britt.) et conifères de l’est du Québec, Canada. Deux sites distants de 90 km ont été utilisés, Armagh et Duchesnay, et chaque site avait quatre répétitions des traitements dans un dispositif en blocs aléatoires. L’effet sur la lumière disponible a été le même dans les deux sites, les coupes à 0 %, 40 %, 50 %, 60 % et 100 % transmettant en moyenne 5 %, 21 %, 26 %, 30 % et 94 % de la pleine lumière, respectivement, durant le premier été. La température du sol n’a été augmentée que dans la coupe à 100 % (4-5  °C du maximum journalier). La perturbation du sol durant la récolte a été plus forte à Duchesnay qu’à Armagh, ce qui a nettement amélioré la réceptivité des lits de germination, particulièrement pour le bouleau jaune. Après 5 ans, les aires traitées contenaient 21 000 à 48 300 semis/ha à Duchesnay, comparativement à 5 500 à 10 500 semis/ha à Armagh. Des pertes significatives de conifères préétablis ont été observées dans les deux sites, mais un recrutement de semis ne s’est par la suite produit qu’à Duchesnay. L’épinette rouge (Picea rubens Sarg.) s’est mieux établie dans la coupe à 60 % (4 400 semis/ha) que dans les autres intensités de coupe (1 600 – 2 100 semis/ha), alors que le sapin baumier (Abies balsamea (L.) Mill.) a bien réagi à toutes les coupes partielles. Dans les deux sites, le cerisier de Pennsylvanie (Prunus pensylvanica L.f.) a été la principale espèce compétitrice dans la coupe à 100 %, alors que la densité de l’érable à épis (Acer spicatum Lamb.) et de l’érable de Pennsylvanie (Acer pensylvanicum L.) préétablis a été maintenue ou augmentée dans les coupes partielles. [ABSTRACT FROM AUTHOR]

The term “aboriginal forestry” is used increasingly to describe the evolving role of First Nations peoples in Canadian forestry over the last 30 years. This paper reviews a diversity of experiences and identifies issues that have important implications for governments, forest planners, and First Nations: a forestry regime that reflects the interests of governments and industry rather than those of First Nations; variable implementation of aboriginal rights in forestry practice; benefits and problems of economic partnerships; limitations on consultation, traditional knowledge, and comanagement in forestry; and finally, different forestry paradigms. Among these experiences and issues, we recognise different visions for the participation of First Nations peoples in Canadian forestry. At one end of the spectrum, “forestry excluding First Nations” is no longer accepted. The most common form may be “forestry by First Nations,” representing a role for First Nations within existing forestry regimes. Other options include “forestry for First Nations,” in which forest managers seek to incorporate aboriginal values and knowledge in management activities and “forestry with First Nations,” in which aboriginal peoples are equal partners in forest management. However, aboriginal forestry is better understood as a potential new form of forestry that uses knowledge and techniques drawn from both traditions and conventional forestry and is based on aboriginal rights, values, and institutions. Au Canada, le terme « foresterie autochtone »gagne en popularité pour décrire le rôle grandissant des Premières nations en foresterie au cours des trente dernières années. Cet article passe en revue de nombreuses expériences et identifie des enjeux aux conséquences importantes pour les gouvernements, les gestionnaires forestiers et les Premières nations. Un régime forestier qui reflète les intérêts des gouvernements et des industriels plutôt que ceux des Premières nations, la reconnaissance inégale des droits autochtones dans les pratiques forestières, les bénéfices et les problèmes associés aux partenariats d’affaires, les limites propres à la consultation, la place des savoirs traditionnels et de la cogestion en foresterie et enfin, la variété des paradigmes forestiers composent ces enjeux. Parmi ces expériences et enjeux, nous reconnaissons l’expression de différentes façons de concevoir la participation autochtone à la foresterie canadienne. À un bout du spectre, « une foresterie qui exclut les Premières nations »n’est plus une option acceptable. La vision la plus répandue est probablement celle d’« une foresterie par les Premières nations »signifiant que celles-ci ont un rôle à jouer dans les régimes forestiers existants. Une autre conception est celle de « la foresterie pour les Premières nations »lorsque les gestionnaires forestiers tentent d’intégrer des valeurs et des savoirs autochtones à leurs activités d’aménagement. Enfin, les situations où les autochtones sont partenaires à part entière dans l’aménagement de la forêt s’inscrivent sous la rubrique « la foresterie avec les Premières nations ». Cependant, la foresterie autochtone est mieux comprise lorsqu’elle implique la possibilité d’une nouvelle foresterie qui a recours à des savoirs et des techniques inspirés à la fois des traditions et de la foresterie conventionnelle et qui est fondée sur des droits, des valeurs et des institutions autochtones. [ABSTRACT FROM AUTHOR]

This paper uses hedonic regression techniques to analyze timber bid transactions in central Georgia. Softwood stumpage prices from pay-as-cut transactions are regressed against timber sale and stand characteristics. We identify observable factors that are statistically associated with the volatility of pine sawtimber stumpage prices in the market. The remaining price volatility, defined as market risk, characterizes undiversifiable price volatility in the market. Isolating market risk in this way has implications for relative price risk across predefined timber markets. Applications of this these techniques suggest that analyzing market price variability with total measures alone, such as standard deviation, may provide false senses of timber price risk. Cet article utilise la méthode de régression hédonique pour analyser le cours des transactions de bois d’œuvre dans le centre de la Géorgie. Une régression des ventes de bois d’œuvre et des caractéristiques des peuplements sur le prix des essences résineuses sur pied, défini par les transactions de vente à l’unité, a été réalisée. Nous avons identifié des facteurs observables statistiquement associés à la volatilité du prix du bois sur pied dans le cas du pin de qualité sciage sur le marché. L’autre partie de la volatilité des prix, définie comme le risque du marché, caractérise la volatilité non diversifiable des prix sur le marché. Cette façon d’isoler les risques du marché a des implications concernant le risque relatif de prix à travers des marchés prédéfinis du bois d’œuvre. Les applications de ces techniques suggèrent que l’analyse de la variabilité des prix du marché par des mesures globales seules, telles l’écart type, pourrait conduire à de fausses perceptions du risque de prix du bois d’œuvre. [ABSTRACT FROM AUTHOR]

Wildland fuelbed characteristics are temporally and spatially complex and can vary widely across regions. To capture this variability, we designed the Fuel Characteristic Classification System (FCCS), a national system to create fuelbeds and classify those fuelbeds for their capacity to support fire and consume fuels. This paper describes the structure of the fuelbeds internal to FCCS. Fuelbeds are considered relatively homogeneous units on the landscape, representing distinct combustion environments that determine potential fire behaviour and effects. The FCCS fuelbeds are organized into six strata: canopy, shrubs, nonwoody fuels, woody fuels, litter–lichen–moss, and ground fuels. Fuelbeds are described by several qualitative and quantitative physical and biological variables with emphasis on characteristics useful for fuels management and fire behaviour planning. The FCCS includes 216 fuelbeds that represent the major vegetation types of the United States. The FCCS fuelbeds can be used as presented or modified to create customized fuelbeds with general or site-specific data to address fire science management or research questions. This system allows resource managers to evaluate wildland fuels operations and management activities, fire hazard, and ecological and air quality impacts at small and large spatial scales. The FCCS fuelbeds represent the United States, although the system has the potential for building fuelbeds for international application. [ABSTRACT FROM AUTHOR]

This paper presents a conceptual framework for ranking the crown fire potential of wildland fuelbeds with forest canopies. This approach extends the work by Van Wagner and Rothermel, and introduces several new physical concepts to the modeling of crown fire behaviour derived from the reformulated Rothermel surface fire modeling concepts proposed by Sandberg et al. (this issue). This framework forms the basis for calculating the crown fire potentials of Fuel Characteristic Classification System (FCCS) fuelbeds (Ottmar et al., this issue). Two new crown fire potentials are proposed (i) the torching potential (TP) and (ii) the active crown potential (AP). A systematic comparison of TP and AP against field observations and Crown Fire Initiation and Spread (CFIS) model outputs produced encouraging results, suggesting that the FCCS framework might be a useful tool for fire managers to consider when ranking the potential for crown fires or evaluating the relative behaviour of crown fires in forest canopies. [ABSTRACT FROM AUTHOR]

In this paper, we consider a tactical transportation planning problem in forestry to decide the destination of logs. This problem is generally solved by finding the flow between a set of supply points and demand points. It can be formulated as a linear programming problem involving direct flows between supply and demand points. However, better solutions can be found by using additional flow variables representing flow in potential backhaul routes. However, the number of such variables is often very large. In this article, we provide the basis for backhaul flow planning in forestry. This includes defining the underlying operations research models for both the flow problem and the subproblem to find backhaul routes. The size of the problem in terms of the number of variables increases rapidly with the number of supplies and demands and we describe a column generation approach for its solution. We report on some case studies and industrial systems where the approach has been used. [ABSTRACT FROM AUTHOR]

Site index prediction models are an important aid for forest management and planning activities. This paper introduces a multiple regression model for spatially mapping and comparing site indices for two Pinus species (Pinus elliottii Engelm. and Queensland hybrid, a P. elliottii × Pinus caribaea Morelet hybrid) based on independent variables derived from two major sources: γ-ray spectrometry (potassium (K), thorium (Th), and uranium (U)) and a digital elevation model (elevation, slope, curvature, hillshade, flow accumulation, and distance to streams). In addition, interpolated rainfall was tested. Species were coded as a dichotomous dummy variable; interaction effects between species and the γ-ray spectrometric and geomorphologic variables were considered. The model explained up to 60% of the variance of site index and the standard error of estimate was 1.9 m. Uranium, elevation, distance to streams, thorium, and flow accumulation significantly correlate to the spatial variation of the site index of both species, and hillshade, curvature, elevation and slope accounted for the extra variability of one species over the other. The predicted site indices varied between 20.0 and 27.3 m for P. elliottii, and between 23.1 and 33.1 m for Queensland hybrid; the advantage of Queensland hybrid over P. elliottii ranged from 1.8 to 6.8 m, with the mean at 4.0 m. This compartment-based prediction and comparison study provides not only an overview of forest productivity of the whole plantation area studied but also a management tool at compartment scale. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the impact of various socioeconomic conditions on the value of timber tenures in the province of British Columbia. Two timber tenure models were created, one for short-term timber sale licenses and the other for longer term forest licenses. The short-term model revealed that timber sales that were awarded according to a combination of employment, revenue, and manufacturing criteria yielded $8.63/m3 less revenue than timber sales awarded based on revenue alone. Similarly, the long-term model indicates that manufacturing and employment conditions significantly reduce the bid on forest licenses. In both instances, we suggest that such conditions distort the use of timber, labour, and capital. Therefore, we conclude that recent forest policy changes in the province that removed several of these conditions greatly improved economic efficiency. Nevertheless, distribution impacts are likely to be important because resource rents have potentially been redistributed away from rural communities to the provincial government. [ABSTRACT FROM AUTHOR]

Tree-ring chronologies have been widely used in studies of tree mortality where variables of recent growth act as an indicator of tree physiological vigour. Comparing recent radial growth of live and dead trees thus allows estimating probabilities of tree mortality. Sampling of mature dead trees usually provides death-year distributions that may span over years or decades. Recent growth of dead trees (prior to death) is then computed during a number of periods, whereas recent growth (prior to sampling) for live trees is computed for identical periods. Because recent growth of live and dead trees is then computed for different periods, external factors such as disturbance or climate may influence growth rates and, thus, mortality probability estimations. To counteract this problem, we propose the truncating of live-growth series to obtain similar frequency distributions of the “last year of growth” for the populations of live and dead trees. In this paper, we use different growth scenarios from several tree species, from several geographic sources, and from trees with different growth patterns to evaluate the impact of truncating on predictor variables and their selection in logistic regression analysis. Also, we assess the ability of the resulting models to accurately predict the status of trees through internal and external validation. Our results suggest that the truncating of live-growth series helps decrease the influence of external factors on growth comparisons. By doing so, it reinforces the growth–vigour link of the mortality model and enhances the model’s accuracy as well as its general applicability. Hence, if model parameters are to be integrated in simulation models of greater geographical extent, truncating may be used to increase model robustness. [ABSTRACT FROM AUTHOR]

This paper has three main objectives: (i) to investigate whether the four-quadrant approach introduced by J.S. Maini reveals a useful typology for grouping countries by gross domestic product (GDP) and forest cover per capita, (ii) to determine if the framework can enhance our understanding of the relationship between forest cover and GDP per capita, and (iii) to investigate why countries in the four-quadrant world occupy different quadrants and to determine the principal factors affecting country movement across and within the individual quadrants. The examination reveals that countries can be classified into four broad categories and that GDP and forest cover per capita have a low but consistent level of negative association. After regressing economic, institutional, social capital, and other variables on a country’s occupancy and movement in the four-quadrant world, the results suggest that countries in each quadrant share different characteristics and that factors underlying country movement vary according to the quadrant being observed. Overall, countries with less corruption and higher education are likely to experience increases in both forest cover and GDP per capita, while countries exporting a significant proportion of forest products have a reduced probability of increasing both variables. [ABSTRACT FROM AUTHOR]

This paper aims to assess the influence of canopy cover on lichen growth in boreal forests along a regional forest gradient. Biomass and area gain, and some acclimation traits, were assessed in the old-forest lichens Lobaria pulmonaria (L.) Hoffm., Pseudocyphellaria crocata (L.) Vain., and Usnea longissima Ach. transplanted 110 days in three successional Norway spruce (Picea abies (L.) Karst.) forest stands (clearcut, young, and old forest) repeated along a rainfall gradient (continental, suboceanic, and Atlantic zones) in Scandinavia. Lichen growth peaked in Atlantic rainforests with mean dry matter (DM) gain up to 36%–38%. The alectorioid lichen U. longissima showed the widest range of growth responses and no signs of chlorophyll degradation. Its highest DM gain consistently occurred in clearcuts, whereas the DM gain was close to zero in the shadiest young forest. The two foliose lichens L. pulmonaria and P. crocata exhibited maximal growth rates in old forests, but apparently growth was limited by low light even in old forests. Their DM gain was reduced in the most sun-exposed clearcuts due to chlorophyll degradation and was relatively high under closed young canopies, suggesting a better adaptation to shade. The lichen responses show that a high frequency and dominance of young and dense fast-growing forest stands at a landscape level are not compatible with large populations of these old-forest lichens and that a lack of lichens under an industrial forestry regime may not necessarily be determined by low dispersal efficiency only. [ABSTRACT FROM AUTHOR]

A tree-ring reconstruction of forest tent caterpillar (Malacosoma disstria Hubner) outbreaks was conducted in the Duck Mountain Provincial Forest. Trembling aspen (Populus tremuloides Michx.), balsam poplar (Populus balsamifera L.), and paper birch (Betula papyrifera Marsh.) tree-ring chronologies were used to identify periods of outbreaks from approximately 1800 to 2002. The impacts of the major forest tent caterpillar outbreaks of the 20th century were compared among four stand types and two age classes. The presence of white rings and growth suppression were used to identify three important outbreak periods, 1939–1948, 1961–1965, and 1982–1985, with another large-scale outbreak suspected during the 1870s. A roughly 20-year interval was observed between major outbreaks. Few differences were found between stand types, except during the 1960s, when mixed stands with jack pine (Pinus banksiana Lamb.) registered more growth suppression and white rings. In general, the outbreak signal in the younger sites was variable. The importance of utilizing white rings and growth suppression data together is discussed. The major outbreaks of the 20th century generally started in the north of the Duck Mountain Provincial Forest. The technique was successful at identifying forest tent caterpillar outbreaks during the 20th and late 19th centuries, when no historical surveys were available. [ABSTRACT FROM AUTHOR]