薄木生产时应注意的几个问题

随着经济的发展和人民生活水平的提高，将珍贵树种木材制成的薄木贴在人造板表面作装饰已成为时尚．然而，珍贵树种的木材产量逐渐减少，薄木的价格越来越高，国内各生产企业为了提高薄木出板车和降低生产成本，已将薄木的厚度降到0．5mm以下．但要提高珍贵树种木材的利用率，减少优质木材浪费，生产中还必须注意许多问题，本文就薄木生产时应注意的几个问题加以分析如下。1木方部制如何刻制木方和合理截断原木是能否生产出优质、美观的薄木和提高珍贵树种木材利用率的关键．在截断原木时，应尽量根据原木外部特征，正确判断木材的各种缺陷…     

对降低针叶树伐根的研讨

从提高针叶树种的木材利用率，提高木材质量以及提高造林成活率等几个方面，通过技术、经济的论证，阐述在木材生产中降低伐根的必要性及可行性，达到充分利用森林资源的目的。     

培育措施对桉树木材性质的影响

桉树已成为华南地区最重要外来速生树种，合理高效的培育措施不仅需要提高单位面积木材产量，同时还要求生产出满足木材工业要求的优质原料。概述了国内外有关培育措施对桉树木材产量与材性影响的研究，为今后我国桉树木材生产部门与加工利用部门的密切合作，提供参考。     

提高木材运输船舶能力的探讨

提高木材运输船舶能力的探讨颜学楠（四川省林业轮船运输公司）我省木材运输船舶作为木材水运生产的组成部分，历年以木排的运输为主。近年来，虽然驳船运输所占比重逐年增加，在一定程度上改善了非均衡生产的状况，却尚未从根本上改变洪水期生产、各春季修船的格局，如何...     

集成材冷压机液压系统设计

集成材可免除木材材质的天然缺陷，提高木材的装饰性档次，充分利用木材，使小料集成整料、大料。集成材生产在国外已广泛应用于木制品生产企业中。而对木材资源比较贫乏木材需求量又特别大的我国，迅速发展集成材生产与应用显得十分重要。目前我国生产集成材的企业，其主要设备“集成材冷压机”由国外引进，价格昂贵。为此，江苏保阳冷压机厂立项进行了MH32-15×3型集成材冷压机的研制，已通过鉴定。现根据专家及用户意见，本设计对原样机设计作了改进，解决了冷压机液压系统中的干涉、窜位及泄漏等问题，结构紧凑，性能可靠，提高了设备…     

波谱分析在高温高压水蒸汽处理压缩矩形木材中的应用

１ 概述 高温高压水蒸汽处理制造压缩矩形木材（简称压密材）的工艺技术研究，是以高效利用低质木材，提高木材利用率的物理加工手段。它在提高劣质材密度、强度等物理力学性能指标的同时，还可提高压密材尺寸的稳定性，而且在整个制造工艺过程中不进行木材的切削加工，简化了加工工艺、提高了木材的利用率及生产效率，对提高我国木材利用的总体水平，提高产品质量、获得高附加值产品，保障林业可持续发展将产生深远的影响，因此其发展前景十分广阔。对于高温高压水蒸汽处理制造压缩矩形木材工艺技术的研究，目前国内外刊物尚少有公开的报道…     

木材干燥室防腐环氧树脂涂料

木材干燥室防腐环氧树脂涂料王广阳（黑龙江省东方红林业局第三木材加工厂）刘庆义（哈尔滨木材干燥设备制造公司）１试验目的近年来，随着木材加工工业化程度的不断提高，生产规模的不断扩大，对优质木材的需要量亦越来越大，从而促使木材干燥技术得到很快的发展。然而木...     

木材性质遗传变异规律的研究进展

木材性质的遗传改良是提高木材品质的重要措施之一，许多国家都相继开展了材性的遗传改良工作，以期能生产更多的优质木材。文中概述了国内外木材性质遗传变异规律的研究现状，并展望了进行材性遗传改良的前景。     

国有林场木材采集工艺技术研讨

国有林场是生产商品材的重要基地,针对国有林场当前木材采集生产状况,研讨在新形势下如何提高国有林场采集工艺技术,合理组织木材采集生产作业,以提高木材生产效率、降低木材生产成本.     

我国木材干燥技术的创新途径与发展前景

1. 木材干燥的责任与地位我国木材资源的浪费，大多数是由于湿材未经干燥处理，或处理不当，致使木材降等甚至 失去了使用价值。木材干燥处理的目的在于：（1）防止木材的变形开裂；（2）提高木材的 力学强度，改善物理性能；（3）防止木材腐朽虫蛀；（4）减轻木材的重量，节省运输费用 。从以上所述可以看出，木材干燥业的责任在于改善木材的使用性能并提高它的利用率。同 时由于木材干燥是能耗最大的工序，因此无论从产品质量或从经济效益的角度来看，干燥作 业都是木制品生产中举足轻重的关键性环节之一。2. 木材干燥技术的现状2.1 木材…     

林木低磷胁迫适应机制研究进展

土壤有效磷缺乏在自然环境中是一种非常普遍的现象,近年来世界各国针对植物的觅磷和耐磷机制进行了大量研究,然而目前相关的综述性报道多限于农作物,对林木低磷胁迫适应性的综述性报道尚不多见。在长期进化过程中,林木为利用土壤中现有的含量极低的有效磷,形成了各种适应低磷胁迫的机制。文中从林木根系的形态学变化、根系分泌物对土壤难溶性磷的活化作用、林木对土壤低浓度有效磷的吸收利用以及应对低磷胁迫的遗传调控等方面综述了低磷环境中林木的适应机制,为揭示林木对缺磷环境的适应机理、发掘林木自身对土壤有效磷高效率的吸收利用能力、以及进一步筛选林木的磷高效品种和合理经营管理人工林提供参考。     

An AHP Assessment Of Barriers in Adopting Sustainable Forest Management Practices in The Context Of Carbon Emission Reductions in Cameroon

ABSTRACT

As the role of forests in climate change mitigation is explicitly recognized in the Paris Agreement, the need to enhance the adoption of Sustainable Forest Management (SFM) practices is crucial. Therefore, this paper aims at identifying and evaluating barriers in adopting SFM practices in the context of forest carbon emission reductions. A total of 15 barriers in adopting SFM practices are listed through literature and expert inputs. Using Cameroon as a case study, the listed barriers are then evaluated by experts to determine their relative importance using the Analytical Hierarchy Process (AHP) method. According to our findings, the ‘Regulatory and Legislative frameworks’ barrier category was attributed to the highest importance among other categories, in adopting SFM practices in the forestry sector. ‘Inadequate political will and incentive to enforce regulations’ appears to be the major obstacle in adopting SFM practices in Cameroon. As carbon emission reduction initiatives are being developed, there is need to move from broad to concrete suggestions that will overcome these barriers. However, proper diagnosis is necessary in order to target barriers with the right incentives and enabling conditions that will support carbon programs and projects to deliver effective emission reductions.     

丁营飞播区林分变化及经营管理措施的研究

根据1976年播后出苗率和成苗率调查,1987--1990年油松毛虫灾害对油松林分的影响,及1991年和2003年丁营飞播区森林资源清查资料,通过调查数据对比分析,丁营飞播区播后林分变化规律,符合近自然林业发展规律。面向整个丁营飞播区生态系统,依据近自然林业经营理念,研究丁营飞播区经营管理措施,实现林业经营目标的最大化。     

Estimating “autotrophic” belowground respiration in spruce and beech forests: decreases following girdling

Seasonal fluxes of CO₂ from soil and the contribution of autotrophic (root + mycorrhizal) to total soil respiration (SR) were estimated for a mixed stand of European beech (Fagus sylvatica) and Norway spruce (Picea abies) in Central Europe. Mature trees of each species were girdled in August 2002 to eliminate carbohydrate allocation to roots. SR was measured at distances of 0.5, 1.0, and 1.5/2.0 m from the bole of each tree at 1–2 weeks intervals throughout the fall of 2002 and monthly during the spring and summer of 2003. The contribution of roots and mycorrhizae to total SR was estimated by the decrease in SR compared to ungirdled control trees to account for seasonal patterns evident in controls. SR decreased with soil temperature in the fall 2002 and increased again in 2003 as soil warmed. During most of the study period, SR was strongly related to soil temperature. During the dry summer of 2003, however, SR appeared to be uncoupled from temperature and was strongly related to soil water content (SWC). Mean rates of SR in beech and spruce control plots as well as root densities did not show a clear pattern with distance from the bole. SR decreased to levels below controls in beech within a few days after girdling, whereas spruce did not show a significant decrease until October 2002, 6 weeks after girdling. In both beech and spruce, decreased SR in response to girdling was greatest closest to the bole, possibly reflecting increased mycorrhizal activity close to the bole. Autotrophic respiration was estimated in beech to be as much as 50% of the total SR in the stand. The contribution of autotrophic respiration was less certain for spruce, although close to the bole, the autotrophic fraction may contribute to total SR as much as in beech. The large fraction of autotrophic respiration in total SR requires better understanding of tree level stresses that affect carbon allocation below ground.     

通过RNAi技术抑制杨树c3h基因表达提高糖转化效率

利用克隆得到的毛白杨c3h1基因构建其RNAi抑制表达载体,通过根癌农杆菌介导的叶盘法转化银腺杨无性系84 K,Realtime PCR检测表明其转基因株系323、325和322中c3h1基因表达量较野生型植株分别下调89.04%、82.22%和68.38%;茎横切片组化染色和显微结构观察表明转基因植株木质部发育和木质素沉积方式发生了改变;木质素、纤维素含量测定及苯酚—硫酸法总糖含量与HPLC法可溶性总糖和单糖含量检测结果表明:转基因植株木质素含量平均降低23.00%,最高可达39.71%;酸前处理效率最高提高了41.39%;未经酸处理直接酶解的糖化效率是对照植株的2.34～2.72倍,322株系和323株系比对照植株经酸前处理后再酶解的糖化效率高出81.18%和375.53%。     

水载型木材防腐剂中有效成分固着的影响因素

水载型木材防腐剂在木材防腐市场中占据着主导地位,然而其中的有效成分的抗水流失性差是其存在的主要缺点,这在很大程度上是由于防腐处理材在使用前防腐剂有效成分与木材成分之间的固着反应不充分而造成的,因此提高防腐有效成分在处理材中的固着质量是提高抗流失性的关键.笔者对国内外在水载型防腐剂中有效成分固着方面的研究进行了较为系统、全面的介绍,其中包括木材树种、固着的环境温度与相对湿度、固着时间、木材含水率、防腐剂的保持量、防腐剂成分组成等不同因素的影响,并在此基础上提出了今后的研究方向.     

江西省峡江县城市森林建设规划

以江西省峡江县城市森林为研究对象,通过对城市森林数量、布局等现状的调查和分析,提出了峡江县城市森林建设总体规划目标、总体布局以及建设内容。研究结果表明:按照规划实施,至2020年峡江县城市森林覆盖率将由2010年的60.5%升至68.0%,建成区绿地率由44.6%升至49.7%,建成区绿化覆盖率由49.9%升至53.2%,人均公共绿地面积由12.2m2升至15m2,城市森林生态效益将得到更大发挥,城市生态环境质量将显著提高。该规划的研究成果也将为其他县级城市森林建设规划提供参考。       

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Predicting maize and soybean production in a sheltered field in the Cornbelt region of North Central USA

Shelterbelts (field windbreaks) are an important tool for farming in semi-arid areas but are not commonly used. An obstacle to the adoption of shelterbelts is the lack of site-specific information about the benefits and costs associated with establishing and maintaining them. A group of researchers has been developing a modeling system that will estimate site-specific effects, benefits, and costs for sheltered fields that produce maize or corn (Zea maize) and soybean (Glycine max) in the U.S. Corn Belt region. Akey component of the modeling system is the use of the CROPGRO-Soybean and CERES-Maize models to simulate yield response to microclimatic changes acrossa sheltered field. In this work, we tested the ability of both models to simulate yield in a sheltered field, evaluated the potential yield increase of shelterbelts based on long-term simulations, and compared the influence of shelter induced changes in temperature and windrun on yield. Both models simulated yield increases due to shelter. The soybean model was more responsive to microclimatic differences than the maize model. Long-term simulations generally showed a field level increase in yield due to shelter for maize and soybeans with an average increase of 4.1 and 3.3, respectively. Change in windrun due to shelter is more important in increasing yield than changes in temperature. The CERES-Maize model seems to be more sensitive to changes in windrun than the CROPGRO-Soybean model.