Microstructure of viscoelastic thermal compressed (VTC) wood using computed microtomography

The paper describes for the first time the analysis of the structure of compressed wood using computed tomography. The anatomical structures of Douglas-fir and hybrid poplar before and after densification with the viscoelastic thermal compression (VTC) process were described by pore size distributions and mean pore sizes and compared. The compression of Douglas-fir mainly affected earlywood, while the compression of hybrid poplar mainly occurred in the vessels. In both wood species, the densification resulted in a significant decrease in the pore volumes. The porosity decreased to less than half of the original value for Douglas-fir earlywood and to approximately one-quarter for the vessels in hybrid poplar. The relevant mean pore sizes also decreased dramatically to about one-quarter compared to the original values. In contrast, latewood in Douglas-fir and libriform fibers in hybrid poplar are quite stable under compression. Douglas-fir latewood retained its original structure after compression and did not show any reduction in pore size. The results confirmed that the anatomical structure of VTC densified wood can be described by pore size distributions and mean pore sizes. However, in the case of broad or bimodal distributions, the mean pore sizes are of less significance.     

Conversion of tropical moist forest into cacao agroforest: consequences for carbon pools and annual C sequestration

Tropical forests store a large part of the terrestrial carbon and play a key role in the global carbon (C) cycle. In parts of Southeast Asia, conversion of natural forest to cacao agroforestry systems is an important driver of deforestation, resulting in C losses from biomass and soil to the atmosphere. This case study from Sulawesi, Indonesia, compares natural forest with nearby shaded cacao agroforests for all major above and belowground biomass C pools (n = 6 plots) and net primary production (n = 3 plots). Total biomass (above- and belowground to 250 cm soil depth) in the forest (approx. 150 Mg C ha^?1) was more than eight times higher than in the agroforest (19 Mg C ha^?1). Total net primary production (NPP, above- and belowground) was larger in the forest than in the agroforest (approx. 29 vs. 20 Mg dry matter (DM) ha^?1 year^?1), while wood increment was twice as high in the forest (approx. 6 vs. 3 Mg DM ha^?1 year^?1). The SOC pools to 250 cm depth amounted to 134 and 78 Mg C ha^?1 in the forest and agroforest stands, respectively. Replacement of tropical moist forest by cacao agroforest reduces the biomass C pool by approximately 130 Mg C ha^?1; another 50 Mg C ha^?1 may be released from the soil. Further, the replacement of forest by cacao agroforest also results in a 70–80 % decrease of the annual C sequestration potential due to a significantly smaller stem increment.     

从法正林转向近自然林:德国多功能森林经营在国家、区域和经营单位层面的实践

简要介绍德国林业的发展历史、多功能林业的法律规定和实现多功能目标的近自然林业理论和技术, 分别从经营单位、区域和国家层面分析总结了德国作为林业发达国家开展多功能森林经营的具体实例和初步结果, 提出了在各个层面上多功能森林经营的工作要点和评价效果的方法、指标和标准等可学习借鉴的要点。认为多功能近自然林业的理论是中华民族一直倡导的"真、善、美"的文化理念在林业经营中的具体表达, 我国开展多功能林业有良好的历史文化基础和现实需求动力。     

Empirical Modeling of Mean Residence Time in a Co‐Rotating Twin‐Screw Extruder with Rice Flour

Mean residence time of rice flour in a twin‐screw extruder was determined using a blue tracer. Variables studied included moisture content, screw speed, barrel temperature, and screw configuration. Mean residence time increased with the increase of the barrel temperature and with the addition of reverse and kneading elements. Mean residence time was significantly related to screw speed, moisture content, die pressure, and screw configuration (P < 0.05). An empirical model was developed to predict mean residence time with the ability to reflect the changes of the barrel temperature and screw configuration. The effects of different extrusion operating conditions including screw speed, moisture content, barrel temperature, and screw geometry on the mean residence time were considered in the model. The validity of the developed model was extensively evaluated and verified using different screw geometries and other processing variables. The mean residence times predicted by the developed model are in good agreement with the experimental data.     

A case of a canine pigmented plaque associated with the presence of a Chi-papillomavirus

The seven fully described canine papillomaviruses (CPVs) have been allocated by sequence comparison and other genetic features into three phylogenetic clades. This largely reflects clinical findings, so each sequence of a newly discovered CPV in combination with clinical and pathological details is a valuable piece of evidence. We hypothesize that the genomic sequence of a new CPV can help to predict clinical features and progression, and that this can be tested in subsequent cases. In this case, a 2-year-old female dachshund-mix presented with papillomatosis clinically and histologically characterized as pigmented viral plaques. PCRs using primers evaluated for CPVs successfully amplified papillomavirus (PV) DNA. Sequencing of the products revealed an unknown PV putatively belonging to the PV genus Chi. Rolling circle amplification was used to amplify the entire viral genome. Sequencing revealed a novel PV, designated as CPV8, which was most closely related (63% homology) to the recently discovered CPV4. CPV4 is associated with benign pigmented plaques in pugs. Phylogenetic analysis based on the nucleotide sequences of four viral genes showed that the novel virus was closest to CPV3, CPV4 and CPV5. The presence of viral DNA was confirmed in the lesions by in situ hybridization using specific probes. CPV8 may consequently be regarded as the fourth member of the Chi-papillomavirus genus. All viruses belonging to this genus induce pigmented plaques in dogs. These findings support the hypothesis that genomic sequences can be useful in predicting the clinical features of CPV infection.     

Exploratory multi-criteria analysis in sustainability impact assessment of forest-wood chains: the example of a regional case study in Baden–Württemberg

Sustainability impact assessment (SIA) is a prospective, integrated assessment approach for potential impacts of policy actions. Multi-criteria analysis (MCA) can be used to facilitate a multi-indicator evaluation in this framework in order to foster rational and transparent decision-making processes for SIA. Based on the outputs of the EFORWOOD project, this paper presents an exploratory MCA to a regional forest-wood chain (FWC) in Baden–Württemberg. This assessment is based on a set of sustainability indicators at process level for a baseline year 2005, reference futures ‘A1’ and ‘B2’ following the definition of the IPCC and a bio-energy scenario implanted into the reference future ‘A1’. The indicator values were calculated by the process tool ToSIA. It is demonstrated how time steps for parts of the regional FWC (forest management, harvest and transport to the mill gate) can be evaluated, as well as the outcomes of different scenarios for a time period. For this purpose, a novel software tool, ToSIA-MCA, is used to calculate relative sustainability impact rating (SIR) based on a PROMETHEE II algorithm. Further, we performed uncertainty analysis to test the stability of ranking results in the absence of real preference information with regard to uncertainty in indicator data. By comparing different indicator weighting patterns, the sensitivity of SIR calculation was further tested. The exploratory MCA outcomes are critically evaluated against the background of assumptions, and data used in the regional case, and an outlook is given on the importance to gain stronger stakeholder involvement in real-life applications.     

The Relevance of Economic Data from Forest Accountancy Networks for Forest Management,Research and Politics Consultation

Multifunctional forestry in Germany is characterized by long production periods and highly complex biological–technical processes. Therefore forest enterprises are complex systems, which are closely intertwined with their economic environment. To ensure their economic success, forest enterprises and forest policies need to take the economic development into consideration. The cost accounting scheme of the German Forestry Council provides a basis for management accounting in multifunctional forest enterprises and distinguishes five different production areas whereby intercompany comparisons of different kinds of ownership in forest accountancy networks (FANs) are possible. Results from such a FAN are used to illustrate the economic situation and long-term development of a panel of private forest enterprises. As well these data can support decision-making processes of individual enterprises, forest economic analyses and consultation in forest policy analyses.     

A practical way to integrate risk in forest management decisions

Key message

The concept of expected losses is an appropriate measure for integrating risk in the determination of the optimal rotation period and choice of tree species.

Context

Natural threats are challenging forest management decisions. Essential decisions about the optimal length of a harvest period are often taken without considering risks.

Aims

Here, a practical and easy to apply way to integrate risk in these decisions is shown. Furthermore, it is seen how the rotation period changes according to the risk-type and risk-level.

Methods

The marginal principle of Preßler’s indicator rate is developed further by including the concept of expected losses, leading to an optimal harvest age under risk. The application of the new formula is shown by a simulation, which also visualises the influence on the optimal rotation age.

Results

Whether risk influences the optimal harvest age compared to a risk free solution, depends on the relationship between expected losses in terms of land rent of the succeeding stand and expected losses in terms of value growth of the existing stand. If they are equal, the rotation age stays. If the expected loss on value growth is bigger than on land rent, the rotation period will be shorter, while it will be longer if the relation is inverse.

Conclusion

The concept of expected losses can be applied to practically determine the optimal rotation period under risk.

     

Controlled mechanical ventilation with constant positive end-expiratory pressure and alveolar recruitment manoeuvres during anaesthesia in laterally or dorsally recumbent horses

Objective

To compare the effects of controlled mechanical ventilation (CMV) and constant positive end-expiratory pressure (PEEP) and interposed recruitment manoeuvres (RMs) with those of CMV without PEEP on gas exchange during general anaesthesia and the early recovery period.