三种杨树扦插生根期间内源激素水平的比较研究

用高效液相色谱（ＨＰＬＣ）和气相色谱（ＧＣ）法，分析银白杨、毛白根和山杨的对照、ＮＡＡ处理和ＮＡＡ＋ＢＡ处理硬枝插穗（芽、皮）的内源ＡＢＡ、ＩＡＡ和玉米素含量在扦插生根期间的变化。试验表明，硬枝扦插生根是潜伏根原基存在与否和皮部内源激素平衡两方面的原因决定的。银白杨皮部的ＩＡＡ／ＡＢＡ比值和玉米素含量高，潜伏根原基有迅速恢复生长的条件，能自发生根成活。毛白杨的ＩＡＡ／ＡＢＡ比值和玉米素含量都低，需     

Evaluation of quality indexes of bending performance and hardness for hardwoods

The mechanical properties of 613 small clear specimens of 35 species (11 ring-porous hardwoods, 19 diffuse-porous hardwoods, and 5 softwoods) were evaluated. The aim of the study was to examine indexes of wood quality that are easy to measure and that exhibit a high correlation with bending performance and hardness that are essential properties of hardwood products. The modulus of rigidity, dynamic modulus of elasticity, bending properties (modulus of elasticity, modulus of rupture, stress at the proportional limit, absorbed energy, Tetmajer’s modulus), dynamic energy absorption by an impact bending test, compressive strength parallel to the grain, shear strength, partial bearing strength, and Brinell’s hardness were measured. A high correlation was found between dynamic modulus of elasticity and static modulus of elasticity. Bending stress at the proportional limit was found to be approximately equivalent to the compressive strength parallel to the grain. Static energy absorption correlated with dynamic energy absorption. Tetmajer’s modulus was found to be closely related to the ratio of the initial stiffness within the elastic range to the secant modulus at the maximum load. A high correlation was observed between Brinell’s hardness and partial bearing strength. The difference in the regression coefficients obtained for these correlations between the species groups was small. Part of this study was presented at the All Division 5 Conference of IUFRO, Taipei, October 2007     

国产阔叶树材导管中侵填体和树胶的研究

扫描电镜观察我国１０２种阔叶树材导管，其中４９种有侵填体存在，１２种有树胶存在。侵填体形态有４种类型，即泡沫状、坍塌状和圆球状。树胶分布有３种形式，即堵塞整个导管、胶层附在导管内壁、圆球状胶滴沉积在纹孔上。导管－射线间纹孔口长和宽大于３μｍ和２μｍ的树种具有侵填体，小于３μｍ和２μｍ的具有树胶。对刺槐超薄切片的观察表明，侵填体壁具有分层的初生壁和胞间层，并保留单纹孔。光镜观察３种阔叶树材导管中侵填     

东南亚阔叶树材数据库查询系统

国内研究或鉴定东南亚木材较早的为中国林业科学研究院木材工业研究所。已发表的有陈嘉宝的《十二种柬埔寨重要工业木材的粗视特征及其物理力学性质》一文;1989年又编译了《马来西亚商用木材性质和用途》一书(商用木材74种)。1988年,安徽农学院林产工业研究所卫广扬等主编的《东南亚木材——识别及用途》问世,以近百种进口的马来西亚和菲律宾原木作为木材构造和材性试验的主要材料,共记载针、阔叶树材90余种;因系进口原木,所以不少没有种名;供作材性试验的木材也多为1号标本。以上这些资料各有侧重,有的只有粗视构造,有的虽有显微构造记载但不少没有种名,不利于木材识别;有的虽然作了木材物理力学试验,但试材太少,代表性不强;就已研究的树种数量看也较少,不能满足广大用材者的需求。     

Productivity of European black alder (Alnus glutinosa) interplanted with black walnut (Juglans nigra) in illinois,U.S.A.

Fast-growing woody nurse crops planted among high value hardwoods can produce merchantable biomass early in the life of the plantation. On a productive site in south-central Illinois (U.S.A.), experimental interplantings of European black alder (Alnus glutinosa (L.) Gaertn.) and black walnut (Juglans nigra L.) were established and maintained under a factorial combination of two initial densities and two thinning regimes. This study evaluated the growth response of the alder component of this system. Although alder consistently overtopped walnut, alder mortality began to increase dramatically during the seventh growing season and was nearly complete following the nineteenth growing season. Mean alder cumulative dry mass through year 14 ranged from 19.05 to 58.62 Mg/ha among initial density and thinning treatments. Carbon sequestered in useable bolewood constituted approximately 25 of total biomass. The productivity of the interplanted alder was comparable to that of native forests while constituting only a portion of the stand and without negatively impacting walnut growth or bole quality. These results suggest that, if marketed, alder has the potential to partially offset costs associated with walnut plantation establishment and maintenance.     

API胶接硬木的耐水耐热性能研究

对水性高分子-异氰酸酯胶黏剂(API)主剂进行改性,以提高API的耐水、耐热及胶接硬木的性能。首先对比了不同聚乙烯醇及增塑剂对API性能的影响。然后在API主剂中引入耐水、耐热树脂或外交联剂(三聚氰胺甲醛树脂、酚醛树脂、N-羟甲基丙烯酰胺),讨论了它们对API胶接性能的影响。通过试验得出三聚氰胺甲醛树脂改性API的效果最好,并用正交试验设计优化了主剂的配方,最终合成了适合高档硬木胶接用的水性高分子异氰酸酯胶黏剂。在试验过程中采用日本JIS K6806-2003标准,并用柞木代替桦木提高了胶接难度。     

Bird abundance and diversity across a hardwood gradient within early seral plantation forest

The extensive removal of competing broadleaved shrubs in forest plantations typically results in structural and compositional simplification of early seral habitat. However, information on the tradeoffs between such intensive forestry practices and biodiversity is scant. Here we assess the magnitude and direction of potential impacts of intensive forest management on populations of early seral-associated breeding birds. Observed population declines of several Neotropical migrant bird species are hypothesized to be linked to the loss of early seral habitat on the breeding grounds. We investigated the association between broadleaved hardwood cover and avian abundance and diversity in intensively managed early seral Douglas-fir (Pseudotsuga menziesii) stands of the Pacific Northwest. Bird species richness decreased across an elevational gradient, but did not vary as a function of either local vegetation composition or structure. In contrast, bird abundance was strongly associated with hardwood cover at local and landscape scales, especially for foliage-gleaning species. We found strong support for the existence of a threshold in relative bird abundance as a function of hardwood at the stand scale; abundance doubled with an increase from 1% to ∼6% hardwood and then reached a plateau. Though abundance of leaf-gleaners increased even more strongly across a gradient in hardwood cover, evidence for a distinct threshold was less clear. We conclude that when early seral hardwood forest is scarce, even small increases in hardwood may provide substantial conservation benefits. However, for some species (i.e., foliage gleaners), there may be more direct trade-offs in abundance and juvenile recruitment with hardwood management intensity.     

外源激素对杜梨扦插繁殖效果的影响

采用正交试验设计,对外源激素种类和浓度2个因素分别设置4个水平。最终4种不同外源激素种类及激素浓度对杜梨硬枝扦插繁殖的研究表明:嫩枝扦插选用浓度为600mg/L的外源激素CTK处理,硬枝扦插选用800mg/L的外源激素CTK处理,其扦插效果最好。