Investigation on the DCM extractives of Canadian Arctic fossil woods: the Resolute sample

Summary Chemical Wood analyses carried out on the fossil pine of Resolute (Cornwallis Island), the youngest among the Canadian Arctic fossil woods recently investigated, had shown that it was weakly affected in its main wood constituents with respect to a reference pine. GC/MS analysis of dichloromethane extract, on the contrary, has revealed important changes with reference to the minor wood constituents. Besides the compounds in common with other fossils such as linear hydrocarbons, fatty acids, long chain alcohols and diterpanes, the branched hydrocarbon pristane and some amides of fatty acids were detected. Assumptions on the mechanism of formation of these compounds as well as recent literature on their occurrence are discussed. The fatty acid amides were the first time found in a fossil wood while pristane, usually present in metamorphosed fossil fuels, is normally absent in rather little degraded fossils.The authors are grateful to Dr. N. J. McMillan and Geological Survey of Canada for the donation of the sample.     

森林资源的化学利用

本文阐述了利用森林资源生产化学产品的必要性和重要意义,讨论了作为化工原料的可行性。对化学利用的方法、主要产品及其用途,需要解决的技术问题、利用现状和可能的发展作了简单介绍。针对我国的具体情况,就开展化学利用的研究提出了初步建议。     

Mineralization processes in some samples from the fossil forest of Dunarobba (Umbria, Central Italy)

 Two isolated twigs (samples A and B) from the site of the fossil forest of Dunarobba (Central Italy) were examined to assess both the degree of degradation of the organic fraction and the composition of the inorganic component. Sample A, although showing the presence of minute crystals, is mineralised only to little larger extent with respect to the trunks of the fossil forest and exhibits a wood composition almost comparable to that of the fossil forest. Main minerals are silica, calcite, chloroapatite, chloromagnesite, and clays. Residual terpenes perfectly match, as either components or proportions, those found in the fossil forest trunks. Sample B is much more mineralised and physical parts are hard (sample BII, 84% mineralisation) along with others that are quite loose (sample BI, 62% mineralisation). Goethite constitutes the major mineral in both parts. Calcite, on the contrary, is higher in BII than in BI. In agreement with the literature, goethite is present in the interstitial spaces of the cell walls whereas calcite is found in the cell lumina. The wood components are limited to lignin and terpenes; being absent cellulose or other polysaccharides. BI contains the same types of terpenes present in the fossil trunks, whereas only diterpenes have been found in BII. The samples B contain, with respect to either sample A or fossil trunks, a lower content of fully or partly aromatic sesquiterpenes and diterpenes. This fact is probably due to the oxidative environment of iron deposition. The difference in the mineralogical structures exhibited by the two samples must be searched in the different environmental conditions under which the samples were maintained. In particular, an essential role must have been played by water sources much richer in soluble salts and more differentiated than the current spring waters of the region. Received 6 March 1999     

A forest optimisation model including carbon flows: Application to a forest in Norway

We analyse which management to choose in order to increase the carbon benefit from the 1.342 million ha forest area in Hedmark County, Norway, and the cost of doing this compared to traditional profit maximising behaviour. The model used in the analysis is a dynamic forest management optimisation model which includes the main carbon flows and benefits from the forest area: tree growth and mortality, litter accumulation, decomposition of dead wood and harvest residues, soil processes, end-use of wood products, and saved greenhouse gas emissions from using wood products instead of more energy intensive materials and fossil fuels.     

The chemistry of decayed aspen wood and perspectives on its utilization

Summary The objectives of this research were to investigate the proportion of decayed wood in mature aspen stems, its chemical composition and its potential utility as a fuel or as a substrate for conversion to fine chemicals as part of an integrated utilization scheme. Three sound and ten decayed aspen stems were sampled from a boreal forest site. Stem analysis indicate that on average, 20% of the merchantable stem volume was in advanced decay and that considerable sound wood recovery was possible. Wood specific gravity and chemical composition were determined. The holocellulose content (volumetric basis) in advanced decayed wood was reduced by 67%. Thermal analysis of the wood using a differential scanning calorimeter provided graphical evidence of a different sequence of events occurring during the combustion of decayed wood and a resulting heat content per unit weight that was 40% higher than that of sound aspen wood. A higher degree of enzymatic hydrolysis was attainable with white-rotted aspen wood. Approximately 62% of the theoretical glucose yield was obtained from decayed aspen wood after alkali-peroxide pretreatment followed by a 12 hour hydrolysis using technical grade enzymes. The above information is used to elucidate future opportunities for wood recovery and energy production from decayed wood resources.The authors would like to thank the Ontario Ministry of Natural Resources, Kirkland Lake for their cooperation; and for the technical assistance by Sally Krigstin, John Leigh, Samir Konar, Ganesh Deka and Doug Charles. We would also like to thank Dr. Morris Wayman, University of Toronto, for his advice and inspiration. We are especially grateful to the following persons and companies for supplying us with enzymes and their associated technical literature: Mr. John Bayard of Van Waters & Rogers Ltee, Canada, representing NOVO Industri, Denmark; Mr. Ian Hodge representing the Miles Biotechnology Group, Canada; and Dr. Gunther Eckert, B.A.S.F., Germany for obtaining and forwarding the products and information of Rohm GmbH, Germany. This work has been partially funded by the Edward Johnson Fellowship, University of Toronto     

Carbon,Fossil Fuel,and Biodiversity Mitigation With Wood and Forests

Life-cycle analyses, energy analyses, and a range of utilization efficiencies were developed to determine the carbon dioxide (CO₂) and fossil fuel (FF) saved by various solid wood products, wood energy, and unharvested forests. Some products proved very efficient in CO₂ and FF savings, while others did not. Not considering forest regrowth after harvest or burning if not harvested, efficient products save much more CO₂ than the standing forest; but wood used only for energy generally saves slightly less. Avoided emissions (using wood in place of steel and concrete) contributes the most to CO₂ and FF savings compared to the product and wood energy contributions. Burning parts of the harvested logs that are not used for products creates an additional CO₂ and FF savings. Using wood substitutes could save 14 to 31% of global CO₂ emissions and 12 to 19% of global FF consumption by using 34 to 100% of the world’s sustainable wood growth. Maximizing forest CO₂ sequestration may not be compatible with biodiversity. More CO₂ can be sequestered synergistically in the products or wood energy and landscape together than in the unharvested landscape. Harvesting sustainably at an optimum stand age will sequester more carbon in the combined products, wood energy, and forest than harvesting sustainably at other ages.     

Non-industrial private forest owners' willingness to supply forest-based energy wood in the South Savo region in Finland

The consumption of energy wood in Finland has increased dramatically since the early 2000s, and the region of South Savo is a bellwether for its usage across the country. This increase is partly due to the national policy of sustainable energy, region's wealth of forests but is also dependent on non-industrial private forest owners (NIPF) deciding to sell energy wood. In this study, a survey with a structured questionnaire was conducted among the NIPFs in the region of South Savo to enlarge the understanding of their willingness to sell energy wood in the future and adopt new approaches to forestry that involves energy wood thinning as well as their current production of energy wood. Moreover, the factors influencing forest owner's motivations relating to energy wood thinning as well as information needs were analysed with multivariate techniques. The results show that almost half of the forest owners in the South Savo region had not sold energy wood. However, forest owners within the region generally had positive attitudes towards selling small-sized energy wood and forestry methods that involve energy wood thinning. Moreover, forest owners' willingness to sell different types of energy wood varied, depending on their background. The study suggests that the increase in supply of energy wood presumes both intensified extension services for forest owners and markets that are better organised than at the moment. The results may also prove beneficial in informing policy-makers regarding which specific target group(s) to focus on when promoting energy wood sales among NIPFs and which aspects of energy wood harvesting and sales to promote.     

Response of saproxylic insect communities to logging history,tree species,stage of decay,and wood posture in the central Nearctic boreal forest

Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest management.We used a split-plot ANOVA design to analyze differences in selected saproxylic insects(all arthropod orders and dipteran and parasitic hymenopteran families) emerging from dead wood of sites with different logging histories(horse-logged,mechanically-logged and unlogged),tree species(Populus and Picea),stage of decay(early-and late-decay stages) and posture(standing and downed logs) in the boreal forest of central Canada.No clear effects of logging history were seen for the studied taxa; however,interaction between logging history and other dead wood features was apparent.Cecidomyiidae consistently emerged more from Populus than from Picea dead wood.Most of the studied saproxylic families were more abundant in late-decay than in early-decay wood.Dipterans of the Cecidomyiidae,Ceratopogonidae,Empididae,Mycetophilidae and Sciaridae families,and hymenopterans of the Diapriidae and Ichneumonidae families were significantly more abundant in downed than in standing dead wood.In contrast,Mymaridae was most abundant in standing dead wood.Our study provides evidence that some insects at high taxonomic levels respond differently to dead wood quality,and this could inform future management strategies in the boreal forest for the conservation of saproxylic fauna and their ecological functions.     

A quantitative framework for evaluating the mass balance of in-stream organic debris

A quantitative framework is developed for analyzing the mass budget of in-stream woody debris. Wood budgets are necessary for defining the relative importance of different recruitment processes over short and long periods, for designing spatially explicit simulation models, and for estimating the range of variability. The framework is used to analyze century-long patterns of large woody debris in streams that are governed by episodic forest death (fire and wind), forest growth and chronic mortality, bank erosion, mass wasting, decay, and stream transport. Simplified mathematical expressions are used to represent climatic, hydrologic, geomorphic, and biotic processes. Results are expressed in terms of time series and probability distributions. Predictions include that in areas of longer fire rotation (500 years) toppling of fire-killed trees comprises only 15% of the long-term wood budget yet chronic stand mortality that affect the large standing forest biomass ensures continuous large volumes of wood in streams. In contrast, toppling of fire-killed trees in forest environments with shorter fire rotations (150 years) comprise about 50% of the wood budget and indicates that field observers have a significantly higher chance of encountering low wood volumes in streams. Wood recruitment by bank erosion should increase irregularly downstream and bank erosion recruitment should exceed mortality recruitment at a bank erosion rate of approximately 5 cm per year. Recruitment from debris flows represents the single largest point source of woody debris to streams. The rarity of debris flows, in conjunction with a 3% per year annual decay rate, limits the contribution of wood from debris flows to about 12% of the long-term wood budget. Fluvial transport of wood promotes an increase in both inter-jam spacing and jam volume downstream. The proportion of woody debris transported into a reach in comparison to lateral recruitment approaches an asymptotic maximum of 50% when tree height approaches channel width. The relationships among process rates, their spatial variance across landscapes, and the resulting probability distributions of long-term patterns of wood abundance are proposed as a set of general theoretical principles. New data on wood supply and storage at the network scale are needed to fully test the predictions made in this analysis.     

Forest carbon mitigation policy: A policy gap analysis for British Columbia

Land-based emissions are an important contributor to global climate change. Various jurisdictions worldwide have implemented forest carbon mitigation strategies and policies to reduce their GHG emissions or increase carbon sequestration. Yet the policy literature on forest carbon mitigation is limited, and no attempt has been made so far to systematically document a jurisdiction's existing forest carbon mitigation policies and policy gaps. This paper applies policy gap analysis to policies for GHG and forest management in the province of British Columbia (BC), Canada, as a case study focusing on the challenges posed by existing policies and the opportunities for policy innovation to more effectively promote forest carbon mitigation. This policy gap analysis shows that while BC has an ambitious climate action regime for fossil fuel-based emissions, it has few policies explicitly targeting forests or the use of harvested wood products for carbon mitigation. As a result, forest carbon mitigation is an under-exploited opportunity for the province. Throughout history, forest management policies have evolved in response to changing social values, such as protection of fresh water, fish and wildlife, and biodiversity. As this case study of BC illustrates, it is time for jurisdictions to renew their forest policies to more effectively incorporate opportunities for carbon mitigation.     

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

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

不同营养元素的施肥处理对马尾松近熟林木材基本性质的影响

研究了 4种不同营养元素的施肥处理对马尾松近熟林木材基本性质的影响。结果表明 ,在不同施肥处理后的同一年中 ,N、P、K、NPK施肥处理对木材管胞长、宽及基本密度的影响不同 ,同一施肥处理在不同年度中 ,对上述性质的影响亦异 ,总之 ,无明显变化规律。方差分析表明 4个施肥处理与无施肥处理的管胞长、宽及基本密度差异均不显著 ,生长轮宽度与管胞形态和基本密度都不显著相关。     

秦岭火地塘天然次生油松林倒木储量与分解

粗头直径≥10cm,长度通常≥1m,倾斜度超过45°的死木质残体称为倒木(Harmonetal.,1996)。倒木是森林生态系统的重要组成部分,在森林生态系统中倒木与生产者、消费者、分解者之间都有着密切的营养关系,其结构与功能相互制约,相互影响。倒木对森林中生产者的更新有着不容忽视的作用,为各类植物提供了生境,而且还对森林生态系统的演替起着重要的作用(侯平等,2001);倒木对消费     

Growth inhibition activities of Sugi bark components against Heterosigma akashiwo

In our ongoing efforts to develop new uses for wood-based waste streams, the growth inhibition activities of extracts obtained from Sugi (Cryptomeria japonica) bark were examined against Heterosigma akashiwo, otherwise known as red tide plankton. The Sugi bark was separated into its outer and inner barks and then extracted sequentially with hexane, ethyl acetate, and methanol. Strong inhibitory activities against H. akashiwo were observed in the tests involving the hexane extract from the inner and outer barks, as well as the ethyl acetate extract from the inner bark. Gas chromatography mass spectroscopy (GC–MS) analysis revealed that cubebol, phyllocladanol, 6,7-dehydroferruginol, ferruginol, and sugiol were the main components in the active extracts. These components themselves were then tested for their growth inhibition activities against H. akashiwo. Cubebol and ferruginol showed potent inhibitory activities, whereas phyllocladanol, 6,7-dehydroferruginol, and sugiol were only weakly active. Taken together, these results suggested that the Sugi bark extracts could be used as inhibition reagents against red tide plankton.     

Certification of forestry: A small-scale forester perspective

A perspective is presented on the role of forest certification in general and concerning small-scale forestry in particular. Certification may be viewed as a tool to communicate with consumers, as a tool to influence forest management or as a game of power and money. Market studies indicate that the end consumers have little interest in certification; the process seems to be more of an issue for some large retailers of wood products. The impact of certification on forest management and thus on the environment has not been studied extensively, and the original objective to stop devastation of tropical forests has so far failed. Certification is a new type of regulation, not based on democratic institutions. Equal treatment, correct procedures for appeal and transparency of decision processes are issues of governance yet to be addressed. The market penetration of certification is increasing, but its importance is an open question. One possible scenario is that large retailers and their large suppliers will adopt certification while the large number of smaller forest owners, wood processors and dealers abstain. Small-scale forest owners do well to develop their own standpoint vis-à-vis certification and marketing.     

Wood preservation (carbon sequestration) or wood burning (fossil-fuel substitution), which is better for mitigating climate change?

Context

The effective ways of using wood production with a view to mitigating climate change are still disputed. Currently, there are two major opposing conceptions. One proposes to increase the carbon stock in forests, in wood products or in some kind of long-term wood storage, thus giving primacy to carbon sequestration. The other invokes the concept of biomass carbon neutrality to assert that the substitution of wood for fossil fuels avoids carbon emissions.

Aim and method

This paper contributes to this debate by comparing carbon footprints of heat generation when choosing wood or other fuels as alternatives.

Result

On condition that wood can be preserved with sufficient durability to meet the time frame of the necessary transition towards carbon-free energy resources (decadal to centennial time scales), one can demonstrate that the use of fossil fuels, with the exception of coal, is still preferable. The reasons are that the intrinsic carbon emission factor for wood has the highest value among all fuels in common use and that reference to the concept of wood carbon neutrality neglects the possibility of storing carbon positively in wood for a long time.

Conclusion

The conclusion is that to mitigate climate change it is better to store wood than use it as a fuel.     

闽楠天然林与人工林木材物理力学性质研究

对闽楠人工林和天然林木材物理和力学性质进行了测定和比较分析,结果表明:闽楠天然林木材气干密度和全干密度分别为0.721 g.cm-3和0.680 g.cm-3,人工林木材气干密度和全干密度分别为0.572 g.cm-3和0.535 g.cm-3,闽楠天然林木材密度大于人工林且差异达到极显著水平,但人工林木材密度变异系数却小于天然林。闽楠人工林和天然林木材气干状态下体积干缩率分别为4.935%和6.439%,全干状态下分别为9.330%和11.376%,闽楠人工林木材的尺寸稳定性稍差于天然林,但从木材的差异干缩来看,闽楠天然林和人工林相近,分别为1.75和1.76。闽楠天然林木材端面、径面和弦面硬度分别为7 583 N、6 183 N和6 625 N,稍大于人工林,但差异不显著。闽楠天然林与人工林旋切板背面裂隙率分别为53%和67%,单板厚度的偏差人工林和天然林分别为0.08mm和0.09 mm。由此可知,发展闽楠人工林可以得到质量与闽楠天然林相近的板材。     

Carbon budget of Ontario's managed forests and harvested wood products, 2001–2100

Forest and harvested wood products (HWP) carbon (C) stocks between 2001 and 2100 for Ontario's managed forests were projected using FORCARB-ON, an adaptation of the U.S. national forest C budget model known as FORCARB2. A fire disturbance module was introduced to FORCARB-ON to simulate the effects of wildfire on C, and some of the model's C pools were re-parameterized using data from Canadian forests. Forest C stocks were estimated using allometric equations that represent the relationships between C and net merchantable volume and forest age based on forest inventory statistics. Other pools were included using results from ecological studies related to forest inventory variables. Data from future forest development projections adopted in approved management plans were used as model input to produce forest C budgets for the province's Crown forest management units. The estimates were extended to other types of managed forests in Ontario: parks, measured fire management zones, and private forest lands. Carbon in HWP was estimated in four categories: wood in use, wood in landfill, wood burned for energy, and C emitted by wood decomposition or burning without energy generation. We projected that the C stocks in Ontario's managed forests and HWP (in use and in landfills) would increase by 465.3 Mt from 2001 to 2100, of which 47.9 Mt is from increases in forest C and 417.4 Mt is from HWP C.