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Rehabilitation of cutover stands is often a management objective of landowners who desire improved stand conditions and increased value from future harvest revenues. We evaluated crop tree growth response and quality following precommercial rehabilitation treatments in mixedwood stands degraded through repeated exploitive cutting in Maine, USA. Treatments included control (no rehabilitation), moderate rehabilitation (crop tree release), and intensive rehabilitation (crop tree release plus timber stand improvement). Paper birch (Betula papyrifera Marsh.), red spruce (Picea rubens Sarg.), and eastern hemlock (Tsuga canadensis (L.) Carriere) crop tree diameter increments 0 to 9 years after treatment were greater following rehabilitation than in the control. Diameter increment did not differ between intensities of rehabilitation for any species. For conifers in the lower strata, crop tree height growth and change in crown length were negatively correlated with basal area in larger trees. The occurrence of epicormic branches on paper birches was greater in the rehabilitation treatments than the control. However, most epicormic branches occurred above the height corresponding to the first sawlog. These findings indicate that rehabilitation of mixedwood stands with similar characteristics can result in improved growth of crop trees without jeopardizing the quality of the lower bole in paper birches. [ABSTRACT FROM AUTHOR]

Sustaining the structure, function, and services provided by forest ecosystems in the face of changing climate and disturbance regimes represents a grand challenge for forest managers and policy makers. To address this challenge, a range of adaptation approaches have been proposed centered on conferring ecosystem resilience and adaptive capacity; however, considerable uncertainty exists regarding how to translate these broad and often theoretical adaptation frameworks to on-the-ground practice. Complicating this issue has been movement away, in some cases, from other recent advances in forest management, namely ecological silviculture strategies that often focus on restoration. In this paper, we highlight the areas of compatibility and conflict between these two frameworks by reviewing the four principles of ecological silviculture (continuity, complexity and diversity, timing, and context) from the perspective of global change adaptation. We conclude that given many commonalities between the outcomes of ecological silviculture and conditions conferring adaptive capacity, the four principles remain a relevant starting point for guiding operationalization of often theoretical adaptation strategies. [ABSTRACT FROM AUTHOR]

Traditionally, forest management has focused on forestry-related practices whereas other industries have been managed separately. Forest management requires the integration of all natural resource development activities, along with other anthropogenic and natural forest disturbances (e.g., climate change, pollution, wildfire, pest disturbance) to understand how human activities can change forested ecosystems. The term cumulative effects has been used to describe these attempts to integrate all disturbances to develop an understanding of past, current, and future impacts on environmental, social, and economic components of the system. In this review, we focus on the science required to understand the past, current, and future impacts of the cumulative effects of anthropogenic and natural disturbances on forested ecosystems or their components. We have primarily focused on the terrestrial system with an emphasis on northern forests in Canada. Our paper is not intended to be a comprehensive review of all cumulative effects science but a synthesis of the challenges and approaches currently being used. Central repositories were identified as an approach to deal with issues of availability of remotely sensed data on anthropogenic and natural disturbances. Data integration projects, open data, and well-designed large-scale data collection efforts are needed to provide sufficient data on environmental responses to cumulative effects. As well, large-scale integrated, modularized ecosystem models are needed to bring stressor and environmental response data together to explore responses to, and interactions between, multiple stressors to project these effects into the future and to identify future data collection needs. [ABSTRACT FROM AUTHOR]

Public advisory committees (PACs) are a dominant form of public participation in Canada's Crown forests, providing a venue in which members of the local public can engage and influence sustainable forest management decision-making. In this paper, we examine the experiences of Indigenous participants (relative to non-Indigenous participants) concerning the success of PAC processes. We focus on issues of fairness, equity, and inclusion of Indigenous voices along with an assessment of forest values diversity. Findings from surveys in 2004 and 2016 indicate statistically significant differences between Indigenous and non-Indigenous PAC members regarding their forest values and their evaluation of the success of PAC processes. This work draws attention to the relative experiences of survey participants and the identification of persistent challenges associated with public engagement over the last two decades. Policy recommendations include substantial changes to how we define and measure sustainable forest management in Canada. [ABSTRACT FROM AUTHOR]

Quantifying the age characteristics of a forest can provide valuable information about the forest’s impact on the environment. For instance, the age of a forest can affect the ecosystem’s carbon exchange, soil enzyme activity, and biodiversity. In this paper, we investigate the use of different sampling methods to estimate the age characteristics of three simulated ponderosa pine (Pinus ponderosa Dougl. ex P. Lawson & C. Lawson) forests having different spatial and age patterns. This includes estimating the mean tree age and the age-class distribution of the trees in the forest. The trees in the sample are selected using k-tree sampling, fixed-radius plot sampling, or variable-radius plot sampling, and we compare the properties of the resulting estimators via design-based and model-based approaches. Analyses of the different sampling methods applied to the three forests suggest that the estimator associated with k-tree sampling, with the addition of a few extra trees per plot, is feasible for forests having a spatially mosaic or random spatial pattern. The estimator associated with fixed-radius plot sampling performed well for the forest having a clustered spatial pattern. [ABSTRACT FROM AUTHOR]

The purpose of the paper is to analyse the extent of policy change and learning in the 20 years following the implementation of Ontario's forest sustainability legislation. Extent of policy learning and change towards sustainable forest management are measured using a combination of content, co-occurrence, and textual analysis of the previous Crown Timber Act and the new Crown Forest Sustainability Act, as well as the latter's 1996 and 2009 forest planning manuals. There were four key findings. First, policy change towards sustainable forest management has been limited. Second, although there was an increased number of values mentioned in new legislation and planning manuals, the frequency of timber values remained dominant. Third, although integration occurred among a greater range of values, integration with timber values continued to dominate. Fourth, with respect to policy learning, the achievement of sustainable forest management is now explicit and judged based on evidence regarding the inclusion of a range of values beyond timber. The paper concludes that the transition to the more integrative and responsive policies of sustainable forest management remains a work in progress. [ABSTRACT FROM AUTHOR]

In this paper, we present an approach employing multiobjective optimization to support decision making in forest management planning under risk. The primary objectives are biodiversity and timber cash flow, evaluated from two perspectives: the expected value and the value-at-risk (VaR). In addition, the risk level for both the timber cash flow and biodiversity values are included as objectives. With our approach, we highlight the trade-off between the expected value and the VaR, as well as between the VaRs of the two objectives of interest. We employ an interactive method in which a decision maker iteratively provides preference information to find the most preferred management plan and learns about the interdependencies of the objectives at the same time. The method is illustrated with a case study in which biodiversity is assessed through an index calculated from the characteristics of the forest. Uncertainty is included both through modifying the input data according to the accuracy of current inventory methods and through growth model errors. This uncertainty is described using a set of 25 scenarios. Involving multiple components of risk is a highly relevant approach in multiobjective forestry; however, estimation of the uncertainty of biodiversity needs further attention. [ABSTRACT FROM AUTHOR]

In this paper, we inquire into whether, and by how much, the use in tactical planning of a dense set versus a sparse set of candidate roads can reduce the two major costs (construction and transportation) of forest operations. This inquiry is conducted by using an optimal road location model to generate dense and sparse sets of candidate roads for three different problem instances. These problem instances were then solved using a mixed integer representation of the integrated tactical planning problem. The results show that the use of a dense set versus a sparse set of candidate roads, for all three problem instances, yielded solutions with a mean decrease in transportation and construction costs of 34.34% and 6.94%, respectively. The mean increase in revenue was 1.06%, and the mean increase in the objective function value (revenue minus the total road construction and transportation costs) was 5.62%. In addition, the mapped solutions reveal the spatial attributes of a lower versus a higher cost road network: straighter roads and more efficiently located forks within the road network. These results were obtained to illustrate how reductions in the costs of transportation and road construction can be achieved in tactical planning. [ABSTRACT FROM AUTHOR]

Some ideas of neuro-dynamic programming (NDP) are illustrated by considering the problem of optimally managing a forest stand under uncertainty. Because reasonable growth models require state information such as height (or age), basal area, and stand diameter, as well as an indicator variable for treatments that have been performed on the stand, they can easily lead to very large state spaces that include continuous variables. Realistic stand management policies include silvicultural options such as pre-commercial and commercial thinning as well as post-harvest treatments. We are interested in problems that are stochastic in their basic growth dynamics, in market prices, and in disturbances, ranging from insects to fire to hurricanes. NDP algorithms are appropriate for problems with large dimensions that may lack a simple model of dynamics and stochastic processes. This paper looks at applying these ideas in the context of a multispecies model. Results show that policies obtained using NDP are optimal within a 95% confidence interval or better. The set of states and controls incorporated into our NDP model allows us to develop optimal policies with a level of detail not typically seen in the forestry literature. [ABSTRACT FROM AUTHOR]

This paper presents a simulation-based analysis of a multiple-round timber combinatorial auction in the timber industry. Currently, most timber auctions are single-unit auctions (i.e., each forest stand is sold separately). However, other types of auctions could be applied to take advantage of the various needs of the bidders with respect to species, volumes, and quality. This study aims to analyze the use of combinatorial auction to this specific context using a simulation approach. Various number of auctions per year, periodicity, lot size, and number of bidders are considered as parameters to set up the different market configurations. The outcomes of both combinatorial auction and single-unit auction are compared with respect to different setup configurations. This analysis shows that combinatorial auction can bring more profit for both seller and buyer when the market is less competitive. [ABSTRACT FROM AUTHOR]

Mexican temperate forests, at the southernmost end of the distribution range of this ecosystem, are the world's centre of diversity of pine and oak, with 55 and 161 species, respectively. Such forests are threatened by land-use change, unsustainable forest management practices, and climate change; these threats reduce their diversity, alter the distribution ranges of species, modify disturbance regimes, and reduce ecosystem adaptability. This paper briefly reviews ( i) the ecology of the Mexican temperate forests, ( ii) the ecological basis for the unique diversity of pine and oak species, ( iii) the main disturbances as well as the main drivers of global changes affecting these forests, in particular climate change, and ( iv) the social, economic, and cultural factors to be considered in proposing a new forest management approach. It proposes a new conceptual framework to manage Mexican temperate forests that are in line with ( i) their natural dynamics, ( ii) the rapidly changing and uncertain global environmental, social, and economic conditions, and ( iii) the complex adaptive system approach. This new forest management combines functional zoning, multispecies plantations, and sylvicultural interventions to increase the adaptive capacity of forests as a way to balance the increasing need for timber products with the need for other ecosystem services facing rapidly changing and uncertain future environmental, social, and economic conditions. [ABSTRACT FROM AUTHOR]

This paper develops a simulation-based optimization supply chain model for supplying sawlogs to a sawmill from a forest management unit. The simulation model integrates the two-way flow of information and materials under the stochastic demand of the sawmill production unit. The dynamic optimization model finds the optimum inventory policy ( s, S) that minimizes the total inventory cost for the three supply chain agents - sawmill storage, merchandizing yard, and forest management unit. The model is used to analyze a real sawmill case study in northwestern Ontario, Canada. It was found that the merchandizing yard absorbs shocks of uncertain demand from the sawmill production unit and reduces idle time, but it increases the total cost of the supply chain by $11 802 (about 42%). The optimized model predicts that only 3.5 days of inventory is required at the sawmill storage. The simulation-based optimization supplier model will help in decision-making at the tactical and operational level in the forest products industry supply chain through a two-way flow of information and materials. [ABSTRACT FROM AUTHOR]

Urban forest naturalization has gained momentum within municipal planning and non-governmental organizations. As the interest in naturalization increases, so does the impetus for exploring its conceptual and practical dimensions. Naturalization is a form of ecological restoration with prominent social dimensions. One motivation is reintegrating the urban forest to a greater extent into its surroundings, increasing the habitat available for native species. However, naturalization is not always desirable, as we may want to use and modify certain areas for cultural purposes, or feasible, as some species may be unable to establish in an urban setting. This paper examines the concepts underlying naturalization and how they influence naturalization decisions and goals. It then provides a framework for urban forest naturalness and explores potential applications of naturalness assessments in urban forest management. The framework outlines 37 different biotic and abiotic dimensions of naturalness that can help urban forest decision-makers visualize and manage the urban forest through understanding its individual parts and thus the whole. If a site is weak in particular dimensions, actions can be directed to increase the naturalness of these components. Similarly, some dimensions may be of more interest than others, such as increasing habitat suitability for a particular species. We then offer real and hypothetical examples of applying the framework to urban forest management. The benefits of a naturalized urban forest are many. It provides habitat for native species and has an important role as a biological teaching tool for urban residents. In developing this framework, we hope to expand the discussion on naturalization beyond simply planting native species and ceasing mowing to positioning urban forests in a broader landscape. [ABSTRACT FROM AUTHOR]

The uniform angle index (UAI) is used to characterize the spatial distribution of a forest community or of individual tree species within that community. This study presents an empirical assessment of the performance of a new statistical test used in conjunction with the UAI. In this study, the UAI is applied to observed and simulated communities. The effect of plot size and density are examined and the results are compared with the criteria of the aggregation index R of Clark and Evan (CE-R) and Ripley's L function (RL). The results suggest that the UAI performs well in determining a particular class of spatial pattern and that, in contrast to the CE-R index, it is unaffected by population density because the standard deviation can be estimated when the density is known using a new empirical relationship presented in this paper. The results of this study represent an improvement in the development of the UAI, verifying its performance and confirming its overall utility. Our comparative analysis positions the UAI among its historical competitors, the CE-R and RL criteria. The UAI index, which does not require expensive mapping of tree positions, can produce results that are equivalent to those obtained by RL and more robust and reliable than those obtained by CE-R. [ABSTRACT FROM AUTHOR]