bluuebunny/crossref_metadata_2025 huggingface dataset:
Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec
Authors: Riopel Martin , Bégin Jean , Ruel Jean-Claude
Published: February 2014

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.
Ecological implications for assisted migration in Canadian forests
Authors: Winder Richard , Nelson Elizabeth , Beardmore Tannis
Published: February 2014

Forest ecosystems are already being impacted by climate change as natural migration rates are outpaced by rapidly changing climate conditions. Human-assisted migration has been proposed as a potential management option to maintain optimal health and productivity of Canada's forests; however, a better understanding of the ecological implications is needed to inform decision-making on assisted migration (AM). This paper examines the ecological constraints and consequences of AM, and discusses options for their mitigation at three scales: translocation over long distances (assisted long-distance migration), translocation just beyond the range limit (assisted range expansion), and translocation of genotypes within the existing range (assisted population migration). From an ecological perspective, we find that AM is a feasible management option for tree species and that constraints and consequences can be minimized through careful application of available knowledge and tools.
Urban forest management in small Ontario municipalities
Authors: John Barker E. , Andy Kenney W.
Published: February 2014

Urban forestry has emerged as an important and timely discipline in an urbanizing world. The practice of urban forestry has focused mainly on large urban centres but urban forests in small municipalities provide the same benefits to the residents within and around them. Small municipalities face many challenges similar to those in urban centres but a lack of resources may worsen the negative effects on small municipalities. Urban forestry in Ontario is undertaken by municipalities with little involvement from upper-level governments. Thus, the effectiveness of urban forestry in Ontario is inconsistent and sporadic, with many small municipalities unable to manage urban forests optimally. Ontario's legislative framework governing urban forestry is critiqued and compared to the system employed in the United States. Recommendations are provided for action toward a centralized urban forestry program in Ontario.
Review of the research conducted by the Poplar Technology Center in Chile: 1999–2011
Authors: Zamudio Francisco , Yañez Marco , Baettig Ricardo , Guerra Fernando , Espinosa Cristian
Published: February 2014

Between 1999 and 2002 the Poplar Technology Center (PTC) introduced more than 2000 experimental poplar hybrids originated by the former Poplar Molecular Genetics Cooperative. Between 2002 and 2003, 12 nursery tests were established in central Chile. Initial growth and the presence of pests and diseases were recorded annually. At the end of 2005, about 100 hybrids were selected from nursery tests and planted in four candidacy tests during 2006. Genetic variation of growth and wood properties is still under study. Here, we present a summary of results obtained to date.
Aerial forest herbicide application: Comparative assessment of risk mitigation strategies in Canada
Authors: Thompson Dean , Leach Jeff , Noel Martin , Odsen Sonya , Mihajlovich Milo
Published: February 2014

Herbicide use in forest management is subject to controversy due to potential risks to human and environmental health. Provinces with substantial forest herbicide use are the focus of this comparative assessment of risk mitigation strategies for aerial application of forestry herbicides. This paper explores risk mitigation procedures surrounding treatment prescriptions, herbicide planning and permitting, and operational treatment, against a background of legislative and regulatory requirements. The three major-use provinces have similarly high levels of risk mitigation, including detailed herbicide application plan requirements, use of electronic guidance systems, buffering of environmental sensitivities, pre-spray reconnaissance flights and post-spray auditing. Notable differences include standardizing use of rotary-wing aircraft, use of low-drift nozzles, the rigor applied to aircraft calibration and use of block monitors for detailed meteorological monitoring. These techniques are generally unique to Alberta and are considered best management practices. The routine use of validated aerial dispersal and expert decision support systems (e.g., AgDisp, SprayAdvisor) is recommended, as it could provide significant added value to generic and spatially explicit risk mitigation with multiple applications. It is the opinion of the authors that aerial herbicide applications as performed in all three major-use jurisdictions are highly protective of human and environmental health.
Participatory GIS to mitigate conflicts between reindeer husbandry and forestry in Vilhelmina Model Forest, Sweden
Authors: Sandström Per , Sandström Camilla , Svensson Johan , Jougda Leif , Baer Karin
Published: February 2014

To improve communication between reindeer-herders and other land users, we developed and implemented a system to produce reindeer husbandry plans together with Sami reindeer-herding communities. A central component of our communications strategy was the introduction and use of a participatory GIS (pGIS). We evaluated the potential and limitations of pGIS as a tool for collaborative learning. We concluded that by merging traditional and scientific knowledge in a pGIS, the process of spatial communication has contributed to a more inclusive planning process, and to improved knowledge-sharing. Furthermore, the process has contributed to a more efficient long-term perspective where land use planning focuses on key areas but with solutions applied to the landscape. The Model Forest offered an appropriate platform to facilitate the process.
Evaluating the relationship between trapper harvest of American martens (Martes americana) and the quantity and spatial configuration of habitat in the boreal forests of Ontario, Canada
Authors: Landriault Lynn J. , Naylor Brian J. , Mills Stephen C. , Baker James A.
Published: February 2014

We investigated the relationship between trapper harvest of martens (Martes americana) and the quantity and spatial configuration of marten habitat on traplines in the eastern and western boreal forests of Ontario. We used region-specific habitat models to estimate the total amount of suitable marten habitat on each trapline, and the proportion of each trapline identified as suitable habitat in various patch size classes. To control for variability in trapper success not associated with habitat, we included an index of trapper effort, as well as variables related to access, temperature, and precipitation as covariates in our regression analyses. Region-specific habitat models identified a positive relationship between the proportion of suitable marten habitat on traplines (irrespective of patch size) and trapper success. Although there did not appear to be an effect of patch size on trapper success in the eastern study region, we observed an effect in the western region. Results from the western study region suggest that traplines with suitable habitat in patches ≥500 ha will have higher trapper success than traplines with similar proportions of suitable habitat but distributed in smaller patches. Our study was conducted in a forested landscape (80% of trapline area was forested). Therefore, our findings should not be applied to areas where suitable marten habitat lies in a matrix comprised of a significant amount of non-forested area.
Using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to examine the impact of harvest and fire on carbon dynamics in selected forest types of the Canadian Boreal shield
Authors: Luckai N. , Larocque G.R. , Archambault L. , Paré D. , Boutin R. , Groot A.
Published: February 2014

The objective of the study was to assess the responsiveness of the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to management scenarios that included three rotation lengths (50, 100 and 250 years) under harvest and fire disturbances in six forest types (poplar deep soil, black spruce deep soil, jack pine deep and shallow soils, hardwood mixedwood and other conifer lowland). Outputs from five carbon (C) pools were considered: merchantable stemwood (stump height of 30 cm, minimum DBH of 9 cm and a minimum top diameter of 7 cm), deadwood, soil C, total ecosystem C and cumulative total ecosystem C emissions. Yield curves strongly affected the predicted size of all five pools. Longer rotation lengths led to larger pools with the relative differences between rotation lengths varying with stand types. Pools associated with poplar were usually the largest while those of jack pine on shallow sites were generally the smallest. When compared to the starting point of the simulations, cumulative total ecosystem C and C emissions increased with the 100- and 250-year harvest rotations (HARV100 and HARV250, respectively) and declined with the 50-year harvest rotation (HARV50). Fire disturbances resulted in stable pools of cumulative ecosystem C and declines in C emissions. CBM-CFS3 provided realistic pool values but the authors suggest further development of the model depiction of ecosystem processes, especially with respect to the treatment of respiration. In general, the authors recommend that forest management planners consider using an integrated approach that links multiple proven and accepted models under appropriate model linking software.
An operational method for estimating cold tolerance thresholds of white spruce seedlings in forest nurseries
Authors: Carles Sylvie , Lamhamedi Mohammed S. , Stowe Debra C. , Veilleux Linda , Margolis Hank A.
Published: February 2014

Cold damage leads to the rejection of millions of seedlings each year in northern forest nurseries. Nursery managers need a procedure to estimate the degree of hardening at a specific time in order to make decisions to avoid seedling loss. Estimates based on variables that are quick and easy to measure such as thermal time, a variable quantifying the cumulative effect over time of temperatures below a given threshold, and apical dry mass ratio (DM/FM) hold particular promise. In this study, two-year-old white spruce containerized seedlings were subjected to artificial freezing tests. The progression of DM/FM during the fall was determined and the thermal time was quantified by calculating hardening degree days (HDD) based on air temperature and a specific threshold for white spruce. Results establish that cold tolerance thresholds are associated with easily identifiable specific DM/FM and HDD values for nursery × species × seed source combinations.
Crown–Coastal First Nation governance of the Great Bear Rainforest: An introduction to my research
Authors: Bird Laura Marie
Published: February 2014

This article introduces a 2011 Master’s thesis that undertook two objectives. First, it assesses whether the Coastal First Nations, a coalition of First Nations on the coast of British Columbia, have acquired a share of governmental decision-making authority for three types of decisions: land use zones, ecosystem-based management (EBM) operating rules, and approval of operational plans. Second, it provides an overview of the unique government-to-government process that evolved for the resource management for British Columbia’s North and Central Coast, and the framework for shared decision-making that has been established between the Crown and the Coastal First Nations regarding the three land use planning decisions under investigation.
Using JABOWA-3 for forest growth and yield predictions under diverse forest conditions of Nova Scotia, Canada
Authors: Ashraf M. Irfan , Bourque Charles P.-A. , MacLean David A. , Erdle Thom , Meng Fan-Rui
Published: February 2014

Empirical growth and yield models developed from historical data are commonly used in developing long-term strategic forest management plans. Use of these models rests on an assumption that there will be no future change in the tree growing environment. However, major impacts on forest growing conditions are expected to occur with climate change. As a result, there is a pressing need for tools capable of incorporating outcomes of climate change in their predictions of forest growth and yield. Process-based models have this capability and may, therefore, help to satisfy this requirement. In this paper, we evaluate the suitability of an ecological, individual-tree-based model (JABOWA-3) in generating forest growth and yield projections for diverse forest conditions across Nova Scotia, Canada. Model prediction accuracy was analyzed statistically by comparing modelled with observed basal area and merchantable volume changes for 35 permanent sample plots (PSPs) measured over periods of at least 25 years. Generally, modelled basal area and merchantable volume agreed fairly well with observed data, yielding coefficients of determination (r2) of 0.97 and 0.94 and model efficiencies (ME) of 0.96 and 0.93, respectively. A Chi-square test was performed to assess model accuracy with respect to changes in species composition. We found that 83% of species-growth trajectories based on measured basal area were adequately modelled with JABOWA-3 (P > 0.9). Model-prediction accuracy, however, was substantially reduced for those PSPs altered by some level of disturbance. In general, JABOWA-3 is much better at providing forest yield predictions, subject to the availability of suitable climatic and soil information.
Carbon and nitrogen distribution across a chronosequence of secondary lacebark pine in China
Authors: Li Chunyi , Zha Tianshan , Liu Jinglan , Jia Xin
Published: February 2014

Information about carbon (C) and nitrogen (N) pools is lacking for lacebark pine forests. Ecosystem C (93.38–240.34 Mg C ha−1) and N (6.60–8.63 Mg N ha−1) increased with stand age. This pattern applied to all tree components and litter. However, changes in C and N stocks during stand development showed the reverse U-shaped pattern for the understory and for mineral soil. Mineral soil was the dominant N pool for all stands (79%–96%) and the largest C pool in younger stands (53%–71%). Trees were the largest C pool in older stands (55%–62%). The contribution of trees to ecosystem C and N pools increased with stand age but that of mineral soil decreased with stand age. These findings contribute to the development and evaluation of forest C and N storage models and to forest management for enhancing C sequestration.
TRANSFOR-M: A unique transatlantic forestry Master program leading to a dual European and Canadian degree
Authors: Leblon Brigitte , Spiecker Heinrich , Neuvonen Jorma , Möttönen Marjoriitta , Hamann Andreas , Karlsson Anders , Cahalan Christine , Stadler Marianne , Drummond Alex , Valinger Erik
Published: February 2014

To educate their students in modern sustainable forest and environmental management approaches sensitive to cultural and situational differences, three Canadian (Alberta, British Columbia, New Brunswick) and four European (Albert-Ludwigs- Universität, Freiburg, Germany; University of Eastern Finland, Joensuu, Finland; Swedish University of Agricultural Sciences, Umeå, Sweden; and Bangor University, Wales) universities have developed a new transatlantic forestry Master program leading to a dual European and Canadian post-graduate degree (TRANSFOR-M). The two-year English language program has the following key characteristics: 1) the optimal use of expertise at partner institutions to deliver effective, globally oriented programs in forestry and environmental management; 2) one intensive language course in the language of the host country for the Canadian students; 3) e-learning courses accessible among all partner institutions (and once tested through TRANSFOR-M, to a broader audience); 4) a “thesis” or research project report that is co-supervised by both a Canadian and a European professor; 5) access to work internships to provide practical experience in an international context and increase the employability of the graduate students and 6) two mandatory three-week field courses (one across the four European countries and one across the three Canadian provinces), where all program participants meet.
Canadian national taper models
Authors: Ung Chhun-Huor , Jing Guo Xiao , Fortin Mathieu
Published: February 2014

Work was done to gather stem taper data for most forest tree species across Canada. They were used for producing taper models to be applied for the purposes of the national forest inventory and for regional purposes when regional taper models are not available. The models are based on squared DBH and on measured or predicted tree height. A taper equation based on the dimensional analysis approach was adopted to fit Canadian national taper models using the collected data. The model parameters were estimated using a mixed model for taking into account variance heterogeneity and withintree autocorrelation. In spite of the different protocols for data collection, the accuracy of the proposed stem taper models is similar to that found in previous studies. Consequently, the models seem suitable for pre-harvest estimation of sawlog volume nationally or regionally.
Challenges and implications of incorporating multi-cohort management in northeastern Ontario, Canada: A case study
Authors: Etheridge David A. , Kayahara Gordon J.
Published: February 2014

In northeastern Ontario, the natural fire cycle is long, resulting in large areas of forest in an uneven-aged condition. Under Ontario forest legislation requiring emulation of natural disturbance regimes, extended rotations and multi-cohort management present options that may meet landscape targets. We used a forest management wood supply model to compare scenarios of current even-aged management, extended rotations, and multi-cohort management (adds partial harvesting). Because science-based information to incorporate late successional forest stages into wood supply modeling is lacking in boreal Ontario, we adjusted the current even-aged inputs to account for mid- and late-seral conditions. Based primarily on expert opinion, adjustments were made to the Forest Resources Inventory age, yield curves, and succession rules; and partial harvesting was added. For modeling, we specified three broad succession groupings (even-aged, two- to three-aged, and all-aged) and established targets of 50%, 25% and 25% of the landscape area, respectively. The current even-aged scenario met even-aged targets but not multi-aged targets. Extended rotations and multi-cohort management scenarios met all the succession grouping targets over the long term. Wood supply was highest for the even-aged scenario, slightly lower for multi-cohort management scenario, and much lower for the extended rotations scenario. Road usage and relative cost was highest for the extendedrotations scenario and lowest for the even-aged scenario. Multi-cohort management may represent a compromise between maximizing harvest levels using even-aged management and retaining mid- and late-succession habitat structures.
Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: A fifty-year legacy of forest research continues
Authors: Pitt Doug G. , Lanteigne Len , Hoepting Michael K. , Farrell James
Published: February 2014

Reduction of the stem density of young, naturally regenerating stands through precommercial thinning (PCT) is widely accepted as beneficial for controlling tree species composition, selecting crop trees and improving their growth, and preparing stand structure for subsequent commercial thinning. Less understood and accepted are the forest-level benefits associated with wood fibre yield and value as they relate to the financial returns of PCT. The Green River PCT trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands an average of eight years after overstory removal. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate blocks. In the fall of 2008, following completion of the ninth sequential evaluation of the study’s 48 permanent sample plots, three of the six replicates were clearcut harvested and data were collected to quantify the effects of PCT on the forest value chain. This paper is the introduction to a series of six papers that quantify the rotation-length effects of PCT on: 1) stand dynamics and the yield of roundwood products; 2) harvesting and wood handling costs; 3) root and butt rot incidence, severity, and effects on volume recovery; 4) lumber and fibre-based panel recovery and value; 5) pulp and paper recovery and value; and 6) the overall integration of these costs and benefits.
Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 2 – Efficiency gains in cut-to-length harvesting
Authors: Plamondon Jean , Pitt Doug G.
Published: February 2014

The Green River precommercial thinning trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands an average of eight years after overstory removal. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate blocks. In the fall of 2008, following completion of the ninth sequential evaluation of the study’s 48 permanent sample plots, three of the six replicates were clearcut harvested using a cut-to-length system; data were collected on harvesting, forwarding and loading efficiency. Largely due to increased average tree size, precommercially thinned stands were associated with improvements in both harvesting and forwarding productivity, proportional to thinning intensity. For example, the nominal 6-ft spacing yielded 30% to 35% gains in harvesting productivity, and 16% to 39% gains in forwarding productivity (p ≤ 0.04), these ranges spanning the different levels of operator expertise and block conditions observed. In total, estimated harvesting costs were $12.58/m3 in the unthinned stands, compared to $9.10/m3 in the 6-ft spaced stands (p = 0.02). Such a difference represents a $3.48/m3 savings, which translates into just over $1000 per ha, based on the gross merchantable volume produced in the 6-ft spaced stands.
Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 5 – Kraft and Thermomechanical pulping and pulp quality
Authors: Bicho Paul , Portillo Elmer , Yuen Bernard , Yan Dongbo , Pitt Doug G.
Published: February 2014

Forty-eight years after application, three nominal precommercial thinning (PCT) spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate, balsam fir (Abies balsamea [L.] Mill.)-dominated stands. Following the clearcut harvest of three of these replicates in 2008, chips produced from sawmilling trials (slab-wood) and from the top logs of the sampled trees (top-log) were kraft and thermomechanically (TMP) pulped. In general, top-log chips took longer to kraft pulp, had lower yields, and produced pulps with shorter, finer fibres than the corresponding slab-wood chips, across all PCT treatment levels. The main effects of PCT on pulping occurred with slab-wood chips and not top-log chips. While end-product quality in either kraft or TMP production was generally unaffected by wood from the range of thinnings tested, slight reductions in slab-wood chip density and H-factor suggest that kraft pulping productivity may be reduced by 1.8% with furnish from thinned stands. While these losses could be offset somewhat by lower chip consumption, the economic benefits for a kraft mill are marginal at best, and sharing of fiscal gains across the fibre value chain needs to be explored. Specific refining energy required in TMP production was, however, reduced by 4% with furnish from thinned stands. These results suggest that value-chain optimization is ultimately dependent on the segregation of fibre from different sources, including within-tree and among silvicultural treatments and sites.
Nonlinear multivariate modeling of strand mechanical properties with near-infrared spectroscopy
Authors: Via Brian K. , Jiang W.
Published: February 2014

The purpose of this research was to determine if nonlinear calibrations of near-infrared spectra could improve the prediction of strand mechanical properties. Strands similar in dimension to strands utilized in an oriented strand board composite process were prepared and tested for mechanical properties in three-point bending and then calibrated to near-infrared reflectance spectroscopy. It was found that an additional 7% to 16% of the variation in mechanical properties could be accounted for when second- and third-order terms were applied. Interpretation of models identified the magnitude of importance that various wood polymers play on mechanical properties and this interpretation was validated through wet chemistry. This work is significant because it demonstrates the potential of using near-infrared spectroscopy to monitor shifts in strand mechanical properties prior to wood composite manufacture and it helps to provide the fundamental relationship between near-infrared models, wood chemistry, and the prediction of mechanical properties.
Vis–NIR spectroscopy for the on-site prediction of wood properties
Authors: Kobori Hikaru , Kojima Miho , Yamamoto Hiroyuki , Sasaki Yasutoshi , Yamaji Fabio Minoru , Tsuchikawa Satoru
Published: February 2014

We investigated the feasibility of visible–near-infrared (Vis–NIR) spectroscopy for estimation of wood qualities of fast-growing Eucalyptus grandis. Partial least squares regression (PLSR) models are applied to predict the diameter at the breast height (DBH), lateral growth rate (LGR) and propagation velocity of stress waves (PVSW). It was possible to estimate LGR and PVSW with appropriate accuracy. This suggested that perhaps information in terms of maturation is included in Vis–NIR spectra. The key factors in the validation of PVSW and LGR were the water and cellulose condition in wood.
Broadening modern resource inventories: A new protocol for mapping natural and anthropogenic features
Authors: Castilla Guillermo , Hird Jennifer , Maynes Bryce , Crane Doug , Cosco John , Schieck Jim , McDermid Greg
Published: February 2014

Conventional forests inventories narrowly focus on timber attributes and often neglect other aspects that may be relevant for other purposes. In an effort to broaden the usefulness of these inventories, we introduce a new protocol based on softcopy photo-interpretation for efficiently capturing both natural and anthropogenic features across a variety of landscapes. Salient aspects of this protocol include (1) the combined use of polygon, point and line feature representation; (2) over 50 fields per attribute table; and (3) semi-automated quality control tools. We show an application example over a 3-km by 7-km sample area in central-eastern Alberta.
The effect of storage temperature and duration on northern red oak acorn viability and vigour
Authors: Noland Thomas L. , Morneault Andrée E. , Dey Daniel C. , Deugo Dave
Published: February 2014

Three separate collections of Ontario sources of northern red oak (Quercus rubra L.) acorns were made to determine the effects of long-term cold storage at +2°C, −1°C, and −2°C on their viability and vigour. We measured acorn moisture content, percent germination during storage, speed of germination and total germination values, root regrowth of seeds that germinated in storage, incidence of fungal contamination, and condition of ungerminated acorns. Viability and vigour peaked six to 12 months after acorns were placed in storage, but decreased with continued storage. After 18 months in storage, ≥60% of the acorns germinated in four of the five seedlots tested and, after 30 months in storage, ≥53% of the acorns germinated in three of the five seedlots tested. Acorn viability was only minimally affected by storage temperature; however, since temperatures above −2°C allowed acorns to germinate during storage, the preferred long-term storage temperature was −2°C. Our results suggest that, assuming proper storage conditions, most red oak seedlots will maintain relatively high germination levels when stored at −2°C for 18 months. Seedlots with particularly high initial germination and vigour may be successfully stored for up to 30 months.
White spruce understory protection: From planning to growth and yield
Authors: Grover Brigitte E. , Bokalo Mike , Greenway Ken J.
Published: February 2014

A large component of the boreal mixedwood forest is comprised of aspen and white spruce mixtures of varying proportions and ages. The slower growing white spruce usually starts as an understory component but will succeed to a white sprucedominated stand after aspen break-up. Since both species are utilized by the forest industry, one method of maximizing total yield is to protect the unmerchantable white spruce understory while harvesting the merchantable aspen overstory. Although some of the white spruce understory is lost when the machine corridors are harvested, future conifer yield is augmented by the accelerated growth of the protected spruce component, a result of increased light levels. In a 10 year trial comparing the growth of released versus control understory spruce, annual height growth, diameter growth and volume increment were 76%, 152% and 83% higher, respectively, for the released conifer compared to the control. In order to account for the yield implications in timber supply analysis, accurate forecasts of future stand development can only be obtained through the use of a forest growth model since long-term data are not available. The Mixedwood Growth Model (MGM) has a unique architecture that allows for the modeling of various strata in understory protection stands. This “multi-strata” modeling approach was used to forecast the combined yield of all the strata, including the impact of adjacent strata with regards to light availability. Operational examples of understory protection, data on white spruce release and aspen regeneration, as well as modeled volume forecasts are presented.
Considerations for boreal mixedwood silviculture: A view from the dismal science
Authors: Armstrong Glen W.
Published: February 2014

Since the end of the twentieth century, there have been some notable changes in the economic climate facing forest products companies operating in the boreal mixedwood forest in Canada: low product prices, a strong Canadian dollar, and increasing recognition of the importance of non-timber forest values are major challenges that must be faced by forest managers and provincial governments. In response to these challenges, foresters and governments may need to rethink the objectives of forest management as stated in policy, and to rethink the silviculture prescriptions applied to the forest. This rethinking may well lead to a forest with less annual production (at least in terms of softwood volume), but with greater economic value for timber production. I present results of financial analysis of several alternative management scenarios for the mixedwood component of the Boreal Plains ecozone, and conclude that only very low cost silvicultural prescriptions make sense when silvicultural expenditures are viewed as an investment in future stands. If these silvicultural expenditures are viewed as a cost of current harvesting, they may be large enough to turn a profitable timber harvesting opportunity into a money-losing one.
Growth dynamics of successive post-fire cohorts of black spruce: Is site potential reduced?
Authors: Côté D. , Lupi C. , Gagnon R. , Lord D. , Morin H.
Published: February 2014

Black spruce is one of the main commercial species in boreal forests of North America. It usually forms large and single-species natural stands in eastern Canada, yet in recent years, parts of this area have undergone forest cover regression and the conversion of closed-crown forests to open lichen woodlands, partly due to successive disturbances and regeneration accidents. We studied two successive post-fire cohorts growing at the same site, for which a clear forest cover regression trajectory has already been demonstrated, to assess possible changes in the site potential. The Wilcoxon nonparametric test found significant differences in mean diameter and height growth between cohorts, compared by cambial age, generally with higher mean values for the most recent cohort. There were no indications of growth reduction between the previous and the current cohorts. This paper sets the ball rolling for a discussion on the pertinence of reforestation in this type of recently established open formation, where growth potential (as expressed by diameter and height) seems, at least, maintained.
PRECISION MEASUREMENT OF RADIAL GROWTH AND DAILY RADIAL FLUCTUATIONS IN DOUGLAS FIR
Authors: Warrack G. , Joergensen Chr.
Published: February 2014

The dial indicator, one of industry's precision tools, has been tested over a period of two and a half years to ascertain its suitability as a dendrometer. This study cannot claim to be the first of its kind, nor to yield exhaustive information, and on this basis the instrument should therefore neither be condemned nor accepted in full. The experience gained may be crystallized in a warning The dial indicator is unnecessarily precise for measurement of response of growth to thinning; too many sample trees are required to reduce the influence of biological variation so as to match instrumental precision. The dial indicator is technically inferior to the dendrograph as a recorder of daily fluctuations in stem diameter.The experimental results were found to contribute significantly to a better understanding of the Douglas fir in its relation to environment and silvicuitural management; but in evaluating the experiments as such it should be borne in mind that their original design has been restricted by their basic purpose, namely to test the dial indicator.
THE EFFECT OF SEVERAL VARIABLES ON THE SPECIFIC GRAVITY OF SECOND-GROWTH DOUGLAS FIR
Authors: Wellwood R. W.
Published: February 2014

Second-growth stands of mixed Douglas fir and western hemlock produce wood that varies considerably in quality, expressed as specific gravity, depending upon the factors of position in the stem, crown class and site index. Data were obtained from sample Douglas fir trees removed in a thinning operation on the University Research Forest, Haney, British Columbia. Samples represent three levels in the stem (stump, one-third total height and merchantable top), three major crown classes (Dominant, Codominant and Intermediate) and site indices from 93 to 160.It was determined that wood at the base of the tree was more dense than at the higher levels, although this difference failed to show significance for the better sites. Considering the differences, at the same levels, between trees of the three crown classes, Dominants had significantly lower values of specific gravity than either the Codominants or the Intermediates. No significant differences occurred between the latter two classes. When the variable of site is tested, it is found that the "Good" sites have significantly lower specific gravities than do the "Average" sites, for comparable sections. The interaction between site and crown class reveals that the differences above hold for the mean of all sites, and for "Average" sites, but that on "Good" sites no significant difference exists between any of the crown classes.In managing second-growth stands of this nature the forester should keep in mind the variation in specific gravity that will occur. He can regulate rate of growth of individual trees and of stands, within limits, so as to produce wood of the desired quality.
THE BRITISH COLUMBIA FOREST SERVICE IN THE FIELD OF RECREATION IN PROVINCIAL PARKS AND FORESTS
Authors: Orchard C. D.
Published: February 2014

British Columbia is experiencing a period of industrial expansion resulting in vastly increased populations and attendant aggravation of social and economic problems.It faces increasing and changing demands on natural resources. People are no longer satisfied with trees to meet their industrial needs. They are demanding forests to protect their watersheds, to frame their roadsides, to clothe their scenery. They want trees and forests to foster fishing and sustain and shelter wildlife. Today people have learned about recreation, and they demand trees and forests for recreational use.These new forest uses have great economic significance in addition to whatever social values they may represent. The people of the United States spend more than 12 billion dollars a year on vacation and holiday travel. More than 150 million people were attracted to American National and State parks and recreation areas in 1949, and it has been shown that Glacier National Park alone lured 36,000 visitors and a 14 million-dollar revenue to the State of Montana in that year.British Columbia is interested in this rich new market for its forests and recreation resources. Its first provincial park was set aside in 1911, and during the ensuing 40 years the Provincial park system has grown to 62 areas comprising more than nine million acres. Additional recreational opportunities exist in 36 million acres of Provincial forests.
PERFORMANCE OF SCOTCH PINE RACES UNDER PRAIRIE CONDITIONS
Authors: Cram W. H. , Brack C. G. E.
Published: February 2014

A study was made of the vigor and seed crops of trees comprising six geographic races of PINUS SYLVESTRIS L. The Scottish race exhibited superior vigor and the Russian race highest survival after 41 years of growth, while the Rigensis race proved the most consistent producer of cones in the 1947 to 1952 period. The seeds-per-cone, seed-weight and seed-viability values varied greatly from year to year for individual trees of all races. Thus it would appear that selection of seed trees on the basis of seed characteristics alone has little merit.
A TREE DECADENCE CLASSIFICATION FOR MATURE CONIFEROUS STANDS
Authors: Foster R. E. , Thomas G. P. , Browne J. E.
Published: February 2014

Mature coniferous stands are comprised of trees in varying stages of susceptibility to and deterioration by wood destroying fungi. Individual trees of such stands may be segregated into easily recognized classes by their possession or lack of visible abnormalities indicative of decay. The segregation of trees on the presence or absence of suspect abnormalities may provide reliable information on stand defect.
GROWTH OF IMMATURE DOUGLAS FIR BY TREE CLASSES
Authors: Ker J. W.
Published: February 2014

This report outlines the results of a test of the value of the Tinney-Malmberg and the Schadelin systems of tree classification in estimating the growth rates of individual trees in second-growth stands of Douglas fir. Such tree classifications, that go beyond the recording of d.b.h. and crown class, are shown to increase the accuracy of tree description, at least in terms of probable growth-rate. The auxiliary classifications, i.e., "crown-sides-free" and "crown quality", appear to be almost equally effective in reducing errors in estimates of the rate of diameter growth.Multiple linear regressions were calculated to show the effect upon decadal radial-increment of the independent variables, d.b.h., crown class, and crown quality. Such relationships may provide (1) a guide to relative growth-rate of individual trees in drawing up tree-marking rules and (2) a basis for estimating gross current stand-growth.
FOREST RESEARCH DEVELOPMENTS IN SWEDEN—TRANSLATION
Authors: Streyffert Thorsten , Brandstrom Axel J. F.
Published: February 2014

Up to the beginning of this century, forest research in Sweden was mostly of the trial and error type from which came some step by step improvements in forestry practices but no really sustained progress as they know it today. Modern forest research in Sweden had its modest beginning about 50 years ago. Solidly based on the natural sciences and more recently pushing ahead toward modern machine age developments, Sweden's forest research program is now moving ahead on a broad front and with the strong and eager backing of the forest industries and their organizations, as well as of the Government and the public. Professor Streyffert traces and describes these developments, not only in the more well known fields of silviculture, stand management, forest regeneration, utilization, soil science, etc., but also in the new and fascinating field of forest genetics and forest tree improvement work. Through it all runs a thread of practical reasoning and sound grass roots economics working toward maximum rewards from management of their forest lands.
THE INCIDENCE OF MICROBIOLOGICAL DAMAGE IN UNLINED FLAX FORESTRY FIRE HOSE
Authors: Rose G. R. F. , Mitton M. , Gardner B. J. , Bayley C. H.
Published: February 2014

The circumstances which may lead to microbiological ("mildew") damage in unlined flax forestry fire hose are discussed and it is concluded that damage of this type may be expected to play an important part in reducing the useful life of the hose. A staining technique which permits ready differentiation between fungal mycelia and cellulosic fibres, suitable for use under the microscope, is described. This technique has been applied to the examination of a representative group of specimens taken from 150 samples of hose discarded during use, because of failure. A large majority of the samples showed evidence of severe microbiological attack. The principles underlying the use of textile fungicides, to prevent such attack, are discussed.
FOREST PATHOLOGY IN RELATION TO THE MANAGEMENT OF LODGEPOLE PINE IN ALBERTA
Authors: Nordin Vidar J.
Published: February 2014

A number of disease considerations are discussed as they relate to clear-cutting, selection cutting, and maintaining pure stands of lodgepole pine in Alberta.
A NEW APPROACH TO THE NORTHERN SPRUCE REGENERATION PROBLEM
Authors: LeBlanc Henri
Published: February 2014

Lack of reproduction of black spruce, Picea mariana, in pure black spruce stands in old cut-over areas, has always been a great subject of discussion and one for intensive work among foresters. Many reasons such as the absence of an adequate seed supply stored on top of humus, or adverse germination conditions are said to be partly responsible.This study on the humus of this unregenerated cut-over area, indicates clear cutting of this stand will influence the normal concentration of definite micro-nutrients such as manganese and magnesium.The augmentation of manganese in the soil has a detrimental effect on the growth of plants when, its concentration is too high. The diminution of magnesium, which is an element necessary to stimulate the growth, must create abnormal nutritive conditions of the habitat. This visible lack of equilibrium might be the cause of the absence of seedlings of Picea mariana on certain parts of this cut-over area.
NOTES FROM A TRIP TO THE SOUTHERN UNITED STATES JANUARY, 1953
Authors: Heimburger C. , Holst M.
Published: February 2014

The authors attended the second southern Conference of forest tree improvement in Atlanta, Ga., early in 1953. They visited parts of Virginia, North Carolina, Georgia, Tennessee, West Virginia, Pennsylvania, New York and Massachusetts before and after this Conference and made observations on the distribution, ecological amplitude and appearance of several tree species within the unglaciated parts of their present range. The aim of this was a preliminary evaluation of the materials found, for direct use in forest planting in Canada and for breeding purposes, to enrich the genetic composition of the respective species in Canada and make them more suitable for various uses in forestry. Collections of seeds and scions for strain tests and breeding projects were made. Observations of this kind are presented for red spruce, white pine, the two native aspens, red pine, Norway spruce, Japanese red and Japanese black pine, and other tree species. The value of such observations and of collections of breeding materials is pointed out and the application of the possible results to forest tree breeding problems in Canada is discussed.
OBSERVATIONS ON THE ORIGIN AND EARLY DEVELOPMENT OF A PLANT COMMUNITY FOLLOWING A FOREST FIRE
Authors: Martin J. Lynton
Published: February 2014

The origin of the species on a burned-over area in southwestern Nova Scotia was determined by means of covered plots, and the early stages of succession were followed closely for two years. All of the herbaceous and shrub species which appeared on the area during the first two years were survivors of the fire. Bracken fern showed unquestionable dominance the first year, but its position was severely contested by other herbaceous species and the heath plants during the second year. Seedlings of grey birch and large-toothed aspen appeared the second year and were restricted to patches of bare mineral soil. Sucker growth of red oak, red maple and grey birch was rapid, but it was pruned heavily by deer feeding.
AN ECOLOGICAL STUDY AND DAMAGE APPRAISAL OF WHITE SPRUCE CONE INSECTS
Authors: Tripp Howard A. , Hedlin Alan F.
Published: February 2014

This paper discusses insects which inhabit the cones of white spruce, Picea glauca (Moench) Voss, in Ontario and Saskatchewan. Insects which spend their entire developmental stages within the cone and cause appreciable damage are discussed at greater length. In Ontario, these are the spruce seedworm, Laspeyresia youngana (Kft.) and the spruce cone maggot, Pegohylemyia anthracina Czerny. In Saskatchewan, L. youngana is the main offender. Other insects which are of less economic importance from the standpoint of seed production are gall midges (cecidomyiids) and casual cone feeders.
UNPOPULAR SPECIES AND THEIR INCREASED UTILIZATION
Authors: Wellwood R. W.
Published: February 2014

Why are certain species unpopular? The answer lies in the lack of availability in sufficient quantity, lack of size of the stems, and undesirable characteristics of the wood or wood products. Increased use is often brought about by shortages of more desirable species, and the overcoming of technological and marketing problems associated with the unpopular species.The course in the development of greatly increased use of western hemlock is discussed. Other problem species are briefly considered.The theme of the Topic is one of optimism: unpopularity is often only a temporary condition.
FIBRE LENGTH OF FAST- AND SLOW-GROWN BLACK COTTONWOOD
Authors: Kennedy R. W.
Published: February 2014

The lengths of fibres from fast- and slow-grown black cottonwood trees were measured at comparable heights and ages. Fibre length was found to vary directly and significantly with both growth rate and age from pith. An additional investigation showed that fast-grown sprouts had longer fibres than slow-grown sprouts of equal age collected from the same stump source. The mechanisms regulating fibre length in trees are discussed briefly.