Estimating the net carbon balance of boreal open woodland afforestation: A case-study in Québec’s closed-crown boreal forest

Black spruce (Picea mariana (Mill.) B.S.P.) is the dominant tree species in the Canadian province of Québec’s boreal ecosystem, particularly in the black spruce-feathermoss (BSFM) domain (between the 49th and the 52nd parallels). While black spruce is generally well adapted to regenerate after wildfires, regeneration failure can sometimes occur, resulting in the irreversible conversion of closed-crown BSFM to open black spruce-lichen woodlands (OW). With OWs representing approximately 7% (1.6 M ha) of Québec’s BSFM domain, the afforestation of OWs carries significant theoretical potential for carbon (C) sequestration, which has not yet been evaluated. The main objectives of the study were then: (i) to estimate the theoretical C balance of OW afforestation within the closed-crown BSFM domain in Québec’s boreal forest; (ii) to calculate, using the life cycle analysis (LCA) method, all the GHG emissions related to black spruce OW afforestation in the closed-crown BSFM domain of Québec. The CO2FIX v. 3.1 model was used to calculate the biological C balance between the baseline (natural OW of site index 9 at age 50) and afforestation (black spruce plantation of site index 6 at age 25) scenarios, using the best estimates available for all five recommended C compartments (aboveground biomass, belowground biomass, litter, deadwood, and soil). The simulation revealed a biological C balance of 77.0 t C ha⁻¹, 70 years following afforestation, for an average net sequestration rate of 1.1 t C ha⁻¹ year⁻¹. Biological C balance only turns positive after 27 years. When integrating the uncertainties related to both the plantation growth yield and the wildfire disturbance, the average sequestration rate varies between 0.2 and 1.9 t C ha⁻¹ year⁻¹. GHG emissions are 1.3 t CO₂ equiv. ha⁻¹ for all afforestation-related operations, which is less than 0.5% of the biological C balance after 70 years. Thus, GHG emissions do not significantly affect the net C balance of the afforestation project simulated. Several recommendations are made, mostly centered on the factors influencing the growth rate of carbon stocks and the impact of natural disturbances, to minimize the range of uncertainties associated to the sequestration potential and maximize the mitigation benefits of an OW afforestation project.     

An integrated approach to assess carbon credit from improved forest management

Fossil fuel consumption in recent decades has caused the rise of CO₂ concentration in the atmosphere, with negative consequences on the environment and human health. This study develops a methodological framework to quantify carbon credits from carbon-oriented forest management and evaluates the economic sustainability of their sale. Application of the framework to two forest compartments with long-lasting active management in the Western Italian Alps showed the feasibility of the methodology and provided insights on its replication in other contexts. Particularly, the Carbon-oriented scenario led to a reduction of both the extracted wood volume (10% and 6.5% CASE1 and CASE2, respectively) and Net Present Value (32% and 29%), leading to a carbon credit price of 19.6 € MgCO_2eq^?1? and 44.1 € MgCO_2eq^?1 to counteract these losses.

This work allows us to highlight the factors needed to design and evaluate alternative forest management options while considering the consequences of climate change. Moreover, the hypothesized scenarios include an economic remuneration of the positive externalities provided by sustainable forest management.

Finally, the proposed workflow entails undeniable environmental benefits while contrasting climate change but still looks undesirable with respect to the traditional timber-oriented management in compartments where high-quality wood products can be obtained.     

Leakage of forest harvest changes in a small open economy: case Norway

The effect of changes in roundwood harvests in Norway on the harvests in rest of the world is examined using a global forest sector model. About 60–100% of the harvest change in Norway is offset by an opposite change in the rest of the world. Such leakage rates vary over time, wood category, background scenario, and the size of the harvest change. Asymmetries between the effects of increasing and decreasing the harvests also exist. Hence, the magnitude of leakage rate is case specific, though considerable. Under tightening wood supply there is less need/room to respond to harvest increase/decrease in Norway with incremental/reduced harvests elsewhere. When the use of global forest resources intensifies with increasing wood demand in the future, leakage rates can be smaller than today. It is important to account for harvest leakage in order to avoid overestimating the climate benefits of policies that decrease or increase roundwood harvests. For instance, for full carbon sequestration benefits of increasing harvests for harvested wood products, creating fresh additional demand for these products should be prioritized. Else the origin of raw material and the place of production for these products may change instead of their stock.     

Goshawk breeding densities in relation to mature forest in southeastern Norway

Forest harvesting practices have been assumed to be the main reason for the decrease in Goshawk Accipiter gentilis populations in Fennoscandia during the late 1900s, by reducing prey density, especially grouse and Red Squirrel (Sciurus vulgaris), and preferred hunting habitats (mature forest). In Norway, the highest breeding densities are now found in areas with a high proportion of farmland and urban areas where corvids and pigeons are important prey. To assess the importance of mature forest for Goshawk populations in southeastern Norway, we compared breeding densities from 20 municipalities with different percentages of farmland and mature forest. In multiple regression models, regional breeding densities were positively related to both the percentage of mature forest, and the percentage of farmland and urban areas. We conclude that the recommendation of establishing buffer zones around nest sites will not be sufficient to maintain Goshawk populations if the proportion of mature forest is reduced at a landscape level.     

Seasonal soil CO2 efflux dynamics after land use change from a natural forest to Moso bamboo plantations in subtropical China

Moso bamboo plantations (Phyllostachys pubescens) are one of the most important forest types in southern China, but there is little information on the effects of their establishment and silvicultural practices on soil CO₂ efflux. The objectives of this study were to evaluate the effect of land use change from a natural broadleaf evergreen forest to Moso bamboo plantations and their management practices on soil CO₂ efflux in a subtropical region of China using static closed chamber method. Regardless of the land uses or management practices, the effluxes over a 12-month period had a seasonal pattern, with the maximum effluxes observed in summer and the minimum in winter. Whereas there was no significant difference in the total annual soil CO₂ efflux between the natural broadleaf evergreen forest (BL) and the conventionally managed bamboo forests (CM), soil CO₂ efflux in the intensively managed bamboo forest (IM) was significantly higher. Soil temperature was the most important environmental factor affecting soil CO₂ efflux rates for all three land uses. Soil moisture also had a significant positive correlation with soil CO₂ efflux rates. Soil temperature and moisture had greater influence on soil CO₂ efflux rate in the IM than the CM and BL forests. Soil dissolved organic C had a positive correlation with soil CO₂ efflux rate in the CM, but had no significant correlation with that in the IM or the BL forests. Our study for the first time demonstrated that conversion of the natural subtropical broadleaf evergreen forest to Moso bamboo does not increase soil CO₂ efflux. However, when bamboo forests are under intensive management with regular tillage, fertiliser application and weeding, significantly more soil CO₂ emission occurs. Therefore, best management practices should be developed to reduce soil CO₂ efflux in Moso bamboo plantations in the subtropical regions of China.     

Implementing Australian forest management practices into a full carbon accounting model

Forest management practices affect carbon sequestration and greenhouse gas emissions and must be considered in carbon accounting models. Forest management practices in Australia have varied over time, depending on forest type, regional influences, available markets and site quality. Remote sensing can identify some management actions, such as time of establishment and harvest (clear-cut and heavy thinning) but is less able to detect site preparation methods and continuing management such as fertilisation, pruning and weed control. Greenhouse gas emissions management requires a capacity to predict the effects of differing management practices on quantities of emissions and removals.     

Non-timber forest products in rural Mali: a study of villager use

Malian Forest Service activities and policies have evolved since the beginning of colonialism under the assumption that forests and their products are the property of the government. Today the importance of involving local people in forest management is recognized. The purpose of this research was to determine the range of non-timber forest products local people use either for direct consumption or for income generation and to identify the trees/shrubs that yield these products in natural forests, fallow lands and crop fields. A gender analysis of the data was also conducted. The data were collected from face-to-face structured interviews using open-ended questions of 92 randomly sampled households in six Malian villages. One-half of the interviews were conducted with women and the other half were with men. The study identified 55 different non-timber forest products produced by 108 plant species. Almost all (99%) of the products identified are used for personal consumption, whereas 68% of the products are also used to generate income. Products such as firewood, leaves for sauces, shea nuts for oil/butter, seeds for condiments and nuts/seeds for soap are the most frequently mentioned products collected by women. Different categories of products like utensils/house materials, animal feed and construction materials (thatch, poles, mats) are the products most frequently collected by men. Ninety percent of the products collected are found in the natural forests; 63% are collected from trees on fallow lands and 51% from scattered trees in crop fields. Forest Service support of villagers using non-timber forest products would create an economic relationship between the forest and the local people. This is essential for the protection of the forest because people will safeguard their interests.     

Reshaping forest management in southern Patagonia: a qualitative assessment

Abstract

The intensive forest use has caused a significant transformation around the world. Sustainable forest management (SFM) has emerged as an alternative to address concerns regarding resource use, conservation, and socioeconomic benefits. Evidence suggests that its application remains inconsistent. In Argentina, the national government passed a law addressing management aiming to provide guidelines and incentives to steer practices into a sustainable framework. The objectives were: (a) understand what the concept of SFM means to participants in Tierra del Fuego; (b) identify and assess how different factors influence the adoption of SFM; (c) review the stakeholder perceptions on recent regulatory changes; and (d) identify the steps required for improving management. We conducted 52 semi-structured interviews with stakeholders and parties at the national level. New regulatory arrangements were implemented for a short-time before this research was undertaken, and we could not evaluate the success of reform. The study provided deep insight into the policy-making process, and the views held by different stakeholders. The historical mismanagement of the resource, together with an unfavorable past relationship with authorities, has promoted short-term perspectives which resulted in behaviors inconsistent with SFM. Moreover, the characteristic demographic composition brings a social component not identified in the broader literature as relevant for SFM adoption.     

Potential use of a spatially constrained harvest scheduling model for biodiversity concerns: Exclusion periods to create heterogeneity in forest structure

The objective of this paper is to investigate potential use of a spatially constrained harvest scheduling model for biodiversity concerns. Change in the degree of biodiversity is represented only by spatial characteristics of harvesting patterns of forest stands with different exclusion periods applied to adjacent forest stands. A spatially constrained harvest scheduling model called SSMART (Scheduling System of Management Alternatives foR Timber-harvest) is used for the analysis. It is one of the heuristics to solve a spatially constrained harvest scheduling problem by using the partitioning heuristic. The algorithm incorporated into SSMART is designed to seek a solution for a multicriteria problem with present net value maximum, meeting spatial feasibility and minimizing period-to-period harvest flow fluctuation, approximating even-flow constraints within the 0–1 integer programming framework. Our experimental analysis shows that the longer exclusion period, the less the harvest flow level and the total present net value are derived and the more heterogeneous the forest structure becomes in terms of the forest stand age distribution. It is also shown that the three exclusion period results in a stable forest stand age distribution over the time horizon for our experimental forest. This research supported by the Grants-in-Aid for Scientific Research (No. 09041071) from the Ministry of Education, Science, Sports, and Culture of Japan.     

A forest of grazing and logging: Deforestation and reforestation history of a boreal landscape in central Sweden

Detailed spatial changes in foreststructure in a central Swedish landscape were examinedusing geographic information system techniques. First,the influence of grazing and burning on forest densityand structure in the 19th century landscape wereanalyzed. Then, the development of the landscapeduring the 20th century, together with the impactof modern forest management methods on foreststructure, were analyzed using historical sources. In1907, over 20% of the 2200 hectare study site wassparsely-wooded (12 m³ ha^–1) with old trees.These areas have been reforested with single-storiedmiddle-aged and old pine stands (66 m³ ha^–1in 1989) during the 20th century. Firesuppression and changes in land use from subsistence-to-industrialforestry, facilitated Norway spruceregeneration as undergrowth in open Scots pine standsafter logging. This natural regeneration has, to alarge extent, been cut down and replaced by pineafforestation. During the second half of the 20thcentury, the standing timber volume has steadilyincreased, while the mean age of the forest hasdecreased. Today's young dense forests will result inhigher timber values in the coming decades, but theforest has lost a range of ecological niches.     

The impact of SFM-certification on forest product markets in Western Europe — an analysis using a forest sector simulation model

In the international discussion on labels for sustainably produced wood products based on the certification of sustainable forest management (SFM), little attention has been paid to what is probably the most crucial part of any market-based instrument: the potential impact on forest products markets. This paper analyses the potential impact of SFM-certification on forest products markets using a simulation model of the Western European forest sector. Two scenarios with assumptions regarding certification (chain-of-custody costs, timber supply reduction from certified forests) are projected for the period 1995–2015 and tested against the results of a base scenario (‘business as usual’). In general, the results show that rather modest changes are to be expected from SFM-certification in forest products markets. The market impact of a timber supply reduction from certified forest would be more distinct than the impacts of chain-of-custody costs. Industry gross profits would decrease more than production. Due to the large share of roundwood costs in total costs, the sawmill industry would be affected more by even small changes in raw-material prices than the panel and paper industry.     

Ecological strategies of forest insects: the need for a community-level approach to reforestation

The traditional, single-species approach to forest pest management is considered in light of the range of ecological strategies respresented in forest arthropod communities. Insect population growth and impact depend on host variables subject to silvicultural manipulation, especially during early stages of forest development, but silvicultural practices often induce undesirable responses from non-target insect populations. A suggested approach to forest pest management involves consideration of arthropod community structure, life history traits, and interactions among arthropod and plant species in order to anticipate insect responses and refine silvicultural recommendations accordingly.     

Temporal mapping of deforestation and forest degradation in Nepal: Applications to forest conservation

Deforestation and forest degradation are associated and progressive processes resulting in the conversion of forest area into a mosaic of mature forest fragments, pasture, and degraded habitat. Monitoring of forest landscape spatial structures has been recommended to detect degenerative trends in forest conditions. GIS and remote sensing play an important role in the generation of such data to identify degraded and deforested areas as well as potential areas for conservation. In this study we analyzed forest degradation and deforestation trends in Chitwan district in Nepal, which contains key habitat elements for wildlife in the region. An artificial neural network was used to predict forest canopy density in five classes using Landsat images of the year 2001. Forest canopy density was predicted with 82% overall accuracy. Except riverine forest, forest area of all other forest types was reduced. Terai Shorea robusta forest, which has high commercial value, showed a loss of 23% between 1976 and 1989 and an overall loss of 15% forest covers between the year 1976 and 2001. Deforestation and forest degradation disproportionately reduced the sizes of the different forest types, a finding that has important management implications. The maps presented in this article could be useful to prioritize limited resources for conservation.     

Dissolved Al reduces Mg uptake in Norway spruce forest: Results from a long-term field manipulation experiment in Norway

Dissolved aluminium (Al) in soils, mobilized by acid deposition, is considered a threat to forest health through hampering root growth and nutrient uptake. Since the end of the 1980s dissolved Al in forest soil water plays a key role in the assessment of critical loads of acid deposition. So far, most evidence for toxicity of dissolved Al in forest soil water is based on nutrient solution studies and pot experiments. Here, we present results from one of the few in situ ecosystem-scale forest manipulation experiments to study the effect of Al on mature forest trees. A plotwise addition of dilute AlCl₃ was conducted during seven years in an even-aged spruce forest (Picea abies) in an area in Norway with low acid deposition. Soil solution concentrations of Al were increased to potentially toxic levels (up to 500 μmol L⁻¹) and base cation (Ca + Mg + K) to inorganic Al ratios in the soil solution in the root zone were mostly below 1 in the Al-addition treatments. In the control treatment (only water addition) Al concentrations did not exceed 15 μmol L⁻¹ and base cation to inorganic Al ratios were above 1. The toxic effects of Al on fine root growth and plant growth found in hydroponic studies and pot trials are not confirmed by this field manipulation. However, magnesium (Mg) contents in needles decreased significantly and persistently in plots with elevated Al concentrations, whereas the needle Ca content did not respond. The depletion of the Mg content in needles is suggested to be due to antagonistic effects of high Al concentrations at the root surface, consistent with observed reductions in Mg to Al ratio of inner bark. This study clearly supports a role for Al in critical load functions for forests as dissolved Al causes a decrease in uptake of Mg. However, other signs of reduced forest vitality were not observed. Soil base cation status may need to be included in risk evaluations of forest health under acid deposition.     

A protocol to estimate epiphyte biomass in a forest management unit: case of Cameroon

Vascular epiphyte biomass is poorly studied in Congo Basin forest. The aim of this study was to develop a protocol to estimate epiphyte biomass. Epiphytes were collected on 77 phorophytes of diameter 57–169.5 cm, oven-dried for biomass. Allometric equations for epiphyte biomass were developed with diameter and phorophyte height as predictor variables using regression analysis. The mean epiphyte biomass was 24.48 kg/phorophyte with a standard deviation of ±49.99. Cylicodiscus gabunensis and Triplochiton scleroxylon hosted the greatest epiphyte biomass with a mean vascular epiphyte biomass of 71.65 and 62.3 kg/phorophyte, respectively. Kruskal–Wallis test (p = 0.005) showed that there was a significant difference between epiphyte biomass with respect to phorophyte species. The relationship found between epiphyte biomass and dendrometric variables of the phorophytes were intermediate (Adj.R² < 0.630) meaning epiphyte biomass increased with increasing tree diameter. However, models with diameter input variables had greater prediction than input variables of total height. Based on the Akaike Information Criterion (AIC), the allometry lnY = ?21.37 + 5.21 x ln(D) ?0.35 x ln(H) with AIC (183) was the best equation for the prediction of epiphyte biomass. These findings shall contribute to REDD+ (Reducing Emissions from Deforestation and Forest Degradation) strategy for climate change mitigation in Congo Basin.     

Nutrient cycling and biomass flows in a low-quality forest stand improvement system in the Lesser Khingan Range of China

The material flow and bulk internal flow analyses were used to establish a material accumulation and cycling model for a low-quality forest stand improvement system and a series of processes were considered. The model was applied in a one-hectare low-quality forest plot in the Lesser Khingan Range of China. Results showed that during 1997–2007, the stands absorbed 270.19 kg of N, 74.28 kg of P, and 124.39 kg of K from soils, 51.82 kg of N and 2.38 kg of P were directly absorbed by foliage, and 16.25 kg of K was released to soils by eluviation. Until 2007, the accumulated nutrients in the stands included 236.91 kg of N, 65.28 kg of P, and 108.55 kg of K. When horizontal strip clearcutting was applied in 2007, 50% accumulated nutrients in the stands were shifted due to harvesting operations, and 212.74 kg of N, 26.97 kg of P, and 98.88 kg of K were accumulated in soils, declining by 9.47% for N, 3.68% for P, and 17.60% for K, respectively, compared with year 1997. 94.61 t per hectare of biomass was generated, of which the biomass in stands accounted for 87.36%. The felled tree biomass was 36.89 t per hectare, of which 84.90% and 10.03% of biomass were utilized in terms of logs and other means, and the rest was left on site.     

外来入侵种及其对森林生态系统的威胁:概念和对策

外来入侵种问题越来越受到关注，其对经济、人类生活、环境和生物多样性的危害也被广泛认识。结合介绍外来入侵种的定义、危害性和入侵过程，对入侵种的生物学特征、易受入侵种危害的生态系统的特征和控制措施进行了归纳；结合国内外研究和管理现状，对我国的外来入侵种研究和管理对策提出了具体建议。     

Risks to forest carbon offset projects in a changing climate

When included as part of a larger greenhouse gas (GHG) emissions reduction program, forest offsets may provide low-cost opportunities for GHG mitigation. One barrier to including forest offsets in climate policy is the risk of reversal, the intentional or unintentional release of carbon back to the atmosphere due to storms, fire, pests, land use decisions, and many other factors. To address this shortcoming, a variety of different strategies have emerged to minimize either the risk or the financial and environmental implications of reversal. These strategies range from management decisions made at the individual stand level to buffers and set-asides that function across entire trading programs. For such strategies to work, the actual risk and magnitude of potential reversals need to be clearly understood. In this paper we examine three factors that are likely to influence reversal risk: natural disturbances (such as storms, fire, and insect outbreaks), climate change, and landowner behavior. Although increases in atmospheric CO₂ and to a lesser extent warming will likely bring benefits to some forest ecosystems, temperature stress may result in others. Furthermore, optimism based on experimental results of physiology and growth must be tempered with knowledge that future large-scale disturbances and extreme weather events are also likely to increase. At the individual project level, management strategies such as manipulation of forest structure, age, and composition can be used to influence carbon sequestration and reversal risk. Because some management strategies have the potential to maximize risk or carbon objectives at the expense of the other, policymakers should ensure that forest offset policies and programs do not provide the singular incentive to maximize carbon storage. Given the scale and magnitude of potential disturbance events in the future, however, management decisions at the individual project level may be insufficient to adequately address reversal risk; other, non-silvicultural strategies and policy mechanisms may be necessary. We conclude with a brief review of policy mechanisms that have been developed or proposed to help manage or mitigate reversal risk at both individual project and policy-wide scales.     

Ethical analysis: A structured approach to facilitate the resolution of forest conflicts

The complexity of natural resource conflicts is often due to the original issues becoming hidden amongst the differing perceptions of the situation. These perceptions are based on the interests, values and principles of those concerned. The resulting complexity makes resolution of the conflict extremely difficult. Ethical analysis (EA) is a tool that could lay the groundwork for resolution of complex natural resource conflicts. The fundamental task of EA is to map and understand the interests, values and principles of the conflicting parties, thereby presenting the conflict's core drivers. It attempts not to solve the problem but to help the parties to understand their own and other parties' values and interests; increasing awareness of the parties' principles, values and moral codes and of those of their opponents, which will make possible a shared perception of reality, vital for resolution. This self-reflection and improved mutual understanding encourages honesty in subsequent attempts at resolution; promoting trust in the other groups' commitment to resolving the conflict. In short, EA enables cutting through the myriad of perceptions to get to the heart of the conflict, and present it in a manner facilitating the next stage of the process, namely, resolution.     

Risk management: A probe and study on forest fires

The subject of risk management is attracting more and more attention around the world. The risk of forest fire disasters should be faced and dealt with for forest fires cannot be avoided. Treating forest fire disasters as a risk management issue promotes important measures and methods for fire fighters to prevent, reduce and control the risks of forest fires. In this paper, the risk concept and risk connotation as well as the management risks for forest fire suppression are discussed clearly. Issues such as risk judgments, risk analysis, risk control and the assessment of risk, including their contents and corresponding methods are clarified. Translated from Forest Resources Management, 2006, 2: 24–27 [译自: 林业资源맜理]