毛竹林免耕施肥技术试验研究

在地形复杂、坡度较陡、大雨频繁的毛竹林区,采用免耕施肥技术,既不造成水土流失,又能达到增产的效果。经试验,每年施碳铵70～80kg/亩、尿素15kg/亩的试验区比对照区竹笋增产69.88％,竹材增产34.94％,毛料增产30.93％;每年施碳铵40kg/亩和尿素20kg/亩的示范区比示范前竹笋增产669.2％,竹材增产131.82％,毛料增产97.54％。本研究免耕施肥方法有:开水平沟、竹蒲头打洞和每竹眉形沟施三种,均有明显效果,但三种方法之间无显著差异。     

木材储备基地及其多功能森林经营建设对策

木材战略储备基地作为林业产业发展的重大举措被列入我国“十二五”林业发展规划,以应对我国木材自产不足、外供不济的安全保障问题,但面临速生丰产林用地有限、社会对森林综合需求增加、生产成本上升、效益低下等因素制约。文中在分析木材储备的特征及其森林经营需求的基础上,提出以林分状态存在的活立木储备是低成本、环境友好型、有战略意义的木材储备,而且木材储备基地是一种以物质生产功能为主导的多功能用材林模式;在此基础上,进一步提出了通过建设有生命活力和结构稳定的用材林生态系统来实现有经济效益的木材战略储备基地的多功能森林可持续经营对策。     

12种实木地板尺寸稳定性初探

文章对12种常用实木地板的尺寸稳定性进行研究,结果表明,柚木的尺寸稳定性最好,收缩率为0.33%,膨胀率为0.1%;水曲柳、桦木、纤皮玉蕊尺寸稳定性较差,收缩率均大于2.24%,膨胀率均大于0.35%;其余的8种地板稳定性相差不大,收缩率为1.09%～1.71%,膨胀率为0.16%～0.23%。成品实木地板尺寸变化较小且缓慢,在使用时做好水分处理就可以避免其严重变形。     

三通道刨花干燥机刨花干燥过程自动控制系统初探

文中对三通道刨花干燥机刨花干燥中被控对象的特性、过程控制的方法、检测仪表、调节控制器与调速系统进行了探索与研究。干燥机的热效率高、刨花终含水率均匀、形态好。     

乐昌含笑木材构造和性质

本文对乐昌含笑的木材构造和木材物理力学性质进行了研究。结果表明,乐昌含笑生长迅速,树干通直,其木材纹理直,密度小,质软,结构中而均匀,干缩差异小。且具有易干燥、不翘曲、不弯裂等优点,材性类似于杨树。适于作纸浆和胶合板等用材。     

Characterization of major,unused, and unvalued Indonesian wood species I. Dependencies of mechanical properties in transverse direction on the changes of moisture content and/or temperature

Mechanical property changes due to the moisture content (MC) and/or temperature changes were examined for 15 Indonesian wood species. A static bending test was carried out at 20°C, 65% relative humidity (air-dry), and water-saturated at 20°C (wet-20) and 80°C (wet-80). For individual test conditions, modulus of elasticity (MOE) and modulus of rupture (MOR) increased linearly with specific gravity regardless of wood species; however, maximum deflection did not correlate with specific gravity for any MC or temperature conditions. The relative values of MOE and MOR measured in wet-20 to air-dry conditions were variously affected from slightly to strongly depending on the wood species. However, the relative values always decreased markedly when saturated in water at 80°C, regardless of wood species. The relative MOE, MOR, and maximum deflection values due to the change in MC or MC and temperature combined were independent of specific gravity but may be dependent on wood type: softwood or hardwood.     

Bioremediation of CCA-treated wood by brown-rot fungi <Emphasis Type="Italic">Fomitopsis palustris</Emphasis>, <Emphasis Type="Italic">Coniophora puteana</Emphasis>, and <Emphasis Type="Italic">Laetiporus sulphureus</Emphasis>

This study evaluated oxalic acid accumulation and bioremediation of chromated copper arsenate (CCA)-treated wood by three brown-rot fungi Fomitopsis palustris, Coniophora puteana, and Laetiporus sulphureus. The fungi were first cultivated in a fermentation broth to accumulate oxalic acid. Bioremediation of CCA-treated wood was then carried out by leaching of heavy metals with oxalic acid over a 10-day fermentation period. Higher amounts of oxalic acid were produced by F. palustris and L. sulphureus compared with C. puteana. After 10-day fermentation, oxalic acid accumulation reached 4.2 g/l and 3.2 g/l for these fungi, respectively. Fomitopsis palustris and L. sulphureus exposed to CCA-treated sawdust for 10 days showed a decrease in arsenic of 100% and 85%, respectively; however, C. puteana remediation removed only 18% arsenic from CCA-treated sawdust. Likewise, chromium removal in F. palustris and L. sulphureus remediation processes was higher than those for C. puteana. This was attributed to low oxalic acid accumulation. These results suggest that F. palustris and L. sulphureus remediation processes can remove inorganic metal compounds via oxalic acid production by increasing the acidity of the substrate and increasing the solubility of the metals.An erratum to this article can be found at     

Plastic deformation in small clear pieces of Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis>) during densification with the CaLignum process

Specimens made of clear wood from Scots pine (Pinus sylvestris L.) were compressed semi-isostatically at 25°C in a Quintus press. Pressure ranged from 0 to 140MPa and the maximum decrease in the crosscut area was about 60%. Quarter-sawn and plain-sawn specimens were densified with the inside face (pith side) up or down. A laser-made dot grid on the crosscut area of the uncompressed specimen was used to calculate plastic strains by image analysis of the displacement of dots after compression. Multivariate models were developed to determine the causes of deformation. The lower face was restrained by the press table and remained flat whereas sides attached to the rubber diaphragm became more irregularly shaped when compressed. Most of the total compression occurred below 50MPa and was determined exclusively by pressure. Above 50MPa, wood density was more important and compression was lower in the interior of specimens and in heartwood. Plastic compressive strain occurred predominately in the radial direction and toward the rigid press table. Strains were dependent on the sawing pattern and orientation. The growth rings of quarter-sawn specimens oriented with the outer face (bark side) down tended to buckle.     

Inhibiting factors of symptom development in several Japanese red pine (<Emphasis Type="Italic">Pinus densiflora</Emphasis>) families selected as resistant to pine wilt

Pinus densiflora and P. thunbergii, native to Japan, are highly susceptible to pine wilt disease caused by infection with a pine wood nematode (Bursaphelenchus xylophilus). Trees of these susceptible species have occasionally been found surviving in forests that are extensively damaged by this disease. Seedlings from a part of surviving trees that were selected as resistant families indicate lower mortality rates after the infection. The factors that prevent the symptoms from developing in resistant families of a susceptible species, P. densiflora, as based on the analysis of the pathogens behavior in the tree tissue and the anatomy of the resistant families, are presented in this paper. Nematode populations remained lower in the stems of seedlings from resistant families of P. densiflora than in the stems of non-resistant families. Areas dysfunctional in water transport developed in the stems of resistant families, but did not reach a size large enough to seriously block the ascent of sap. These results suggest that there are systems within the seedlings that prevent nematode migration and reproduction. The 2-year-old seedlings from resistant families of P. densiflora, however, did not suppress the pathogen activity. Numerous branches are a visible characteristic in the seedlings of some resistant families. The arrangement of the resin canals, the only channels in the tree to the pathogen migration, was disoriented at the joints between the branches and the main stem. Such a structure may be effective as a barrier to nematode dispersal.