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41.
F.?Ishiguri S.?Maruyama K.?Takahashi Z.?Abe S.?Yokota M.?Andoh N.?YoshizawaEmail author 《Journal of Wood Science》2003,49(2):135-139
Sugi green logs with red or black heartwood were smoke-heated, and the changes in the color of the heartwood after ultraviolet
(UV) (λ = 365 nm) radiation exposure were then observed. After UV radiation exposure, the redness and yellowness increased in both
the red and black heartwoods, whereas the brightness decreased. In the black heartwood, the resulting color turned from yellowish
white to reddish brown. Reddening in black heartwood after exposure to a combination of smoke heating and UV radiation is
thought to be due to a decrease in brightness and an increase in both redness and yellowness. However, the degree of change
in heartwood color by UV radiation exposure was not greatly affected by smoke-heating treatments of various lengths. When
methanol extracts were fractionated and exposed to UV radiation, the yellowness increased in the n-hexane-soluble portion and the redness increased in the acetone-soluble fractions from the n-hexane-insoluble portion. These results suggest that the n-hexane-soluble fraction contains the substances that allow heartwood color to change to yellow after UV radiation exposure,
and the acetone-soluble-fraction from the n-hexane-insoluble portion contains the substances that allow it to change to red.
Received: November 14, 2001 / Accepted: June 3, 2002
Acknowledgment This research was supported in part by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of
Science.
This study was presented in part at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001
Correspondence to:N. Yoshizawa 相似文献
42.
Fibril angle variability in earlywood of Norway spruce using soft rot cavities and polarization confocal microscopy 总被引:4,自引:0,他引:4
Anna Bergander Jonas Br?ndstr?m Geoffrey Daniel Lennart Sahnen 《Journal of Wood Science》2002,48(4):255-263
The main purpose of this study was to investigate the variability of the fibril angle of tracheids in earlywood of Norway spruce (Picea abies L. Karst.). Polarization confocal microscopy was chosen and compared with the method utilizing the orientation of soft rot cavities. There was a significant correlation between the soft rot and polarization confocal microscopy methods, which showed the same trend of high fibril angles in the first part of the earlywood followed by a decrease toward the end of earlywood. This declining trend was less pronounced in annual rings containing compression wood. Moreover, large variations in fibril angle occurred between neighboring tracheids. The investigation also emphasized the differences between X-ray diffraction and microscopic methods, as the large variation seen by the latter methods is not seen by the X-ray diffraction approach because of its large area of measurement. No correlation was found between fiber morphology (i.e., average length, width, density) and the average fibril angle in the investigated annual rings. 相似文献
43.
Using soft X-ray photography, two-dimensional observations were made of the water distribution within the green stem ofCryptomeria japonica D. Don. Variations in the distribution pattern of the wet area in the horizontal plane of the lower stem were described. The distribution patterns showed extreme variation among individual trees, with broad wet-area distribution types appearing, namely, the regularly distributed wet area and the irregularly distributed wet area. We defined five basic types of wet-area distribution patterns on the basis of their regularity or irregularity. It was concluded that the between-tree variation in the wet-area distribution causes the between-tree variation in the mean moisture content of the heartwood. The distribution patterns of the wet area were similar for individual trees within each plus-tree clone.Part of this paper was presented at 46th annual meeting of the Japan Wood Research Society at Kumamoto, April 1996 相似文献
44.
Understory individuals were found to form patches in a 100-year-old deciduous broad-leaved forest. The closed forest canopy
was uniform, and so the light conditions at various locations across the forest floor differed little after the leaf flush
of the overstory. To explain the distribution pattern in the understory, a hypothesis was proposed: in spring, the forest
floor is divided into patches according to the timing of leaf flush of the overstory individuals, and the light conditions
are more favorable for understory plants under the crowns of trees with later-flushing leaves. In the plot, three groups of
early, intermediate, and late, were recognized in the overstory concerning the timing of leaf flush. As for the start of leaf
flush, a difference of 31.6 days was recognized among tree species, and for the end of leaf flush, a difference of 40.3 days.
In the spring of 1998, the relative photosynthetic-photon-flux density under an intensively studiedCastanea crenata tree (late-flushing species) usually showed higher values than that under a similarly studiedAcer mono tree (early-flushing species). Analysis of the spatial-distribution pattern using Morisita’s1δ index revealed that the understory community had an aggregated distribution. In the overstory, the late- and the intermediate-flushing-species
groups showed aggregated distributions, while the early-flushing-species group showed random distribution. Spatial correlation
between the understory and the overstory was analyzed by using Morisita’sRδ index. The distribution of whole understory community spatially co-occurred with that of the late-flushing-species group
of the overstory. In contrast, the understory community was less developed below the members of the early-flushing-species
group of the overstory. We consider that the data presented here support our hypothesis, and we suggest that the growth and
survival of understory individuals were promoted in the places receiving light for long periods in spring. 相似文献
45.
lNTRoDUCTIONTheon-sitcnon-dcstructit'cmcasurcl11cntofu.oodmoisbocontcntattTactsgrcatintcrcsts.Itpla3'simpor-tantpartsinthescicntificrcscarchsucl1asonthchcatandmasstransportproccssesint"ooddri'ing.thcim-pregnationofliquidinxt'ood.thcmoisturccontcntdistri-b… 相似文献
46.
47.
四川盆地浅丘陵区农林复合系统内部天空散射辐射分布特性理论分析 总被引:1,自引:0,他引:1
根据四川盆地浅丘区农林复合系统特点,从理论上分析了该系统内天空散射辐射令布特征。提出了在林带和地形(坡度变化)的双重影响下的林带间平均相对辐照成分布特征,为农林复合系统的设计提供了依据;除林带本身产生“光胁地”外,地形变化即坡度的增加,叶“光胁地”效应有增强作用,对其范围有扩大作用。 相似文献
48.
杨树微纤丝角的变异及其与木材性质的相关关系 总被引:6,自引:0,他引:6
微纤丝角为细胞次生壁S2层微纤丝排列方向与细胞主轴所形成的夹角,与木材的物理性质、力学性质和化学性质都有着直接的关系。应用x射线衍射法测定了7个杨树无性系(14株样木)胸径处各年轮的微纤丝角,并对应分析和测定了各年轮的木材基本密度、纤维长度、纤维宽度和纤维素含量。研究结果表明,杨树微纤丝角在年轮间存在显著差异,其径向变异规律为从髓心向外以微纤丝角逐渐降低,年轮间的平均微纤丝角在7.8旱?8褐洌荒静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾吭谀曷旨湟泊嬖谙灾钜臁O喙胤治霰砻鳎⑾怂拷怯肽静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾看嬖谙灾母合喙毓叵??0.01),相关系数分别为-0.450、-0.586、-0.516和-0.660。回归分析结果表明,多项式方程可较好地描述杨树微纤丝角与所测定的木材性质的关系,相关系数均在-0.45以上(n=125)。本文的研究结果认为,在今后针对杨树材性改良的育种计划中,微纤丝角是一个重要的选育和改良指标。图3表3参34。 相似文献
49.
ZHOU Haibin LIU Junliang JIANG Zehui Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R. China 《中国林业科技(英文版)》2006,5(1):8-13
INTRODUCTIONWith the implementing of the Natural ForestryProtection policies in China, the plantation forestry willplay a much larger part in meeting the demand for wood.But the plantation wood, especially Poplar and Fir, havecommon properties of soft structure, low density andpoor processing. Generally speaking, these propertiescan be evidently improved by compressing. MasafumiInoue et al. (1991a, 1991b, 1990) had studied thesurface compression of coniferous wood. Their studiesshowed … 相似文献
50.
Spiraea pubescens, a common shrub in the warm-temperate deciduous forest zone which is distributed in the Dongling Mountain area of Beijing,
was exposed to ambient and enhanced ultraviolet-B (UV-B, 280–320 nm) radiation by artificially supplying a daily dose of 9.4
kJ/m2 for three growing seasons, a level that simulated a 17% depletion in stratospheric ozone. The objective of this study was
to explore the effects of long-term UV-B enhancement on stomatal conductance, leaf tissue δ
13C, leaf water content, and leaf area. Particular attention was paid to the effects of UV-B radiation on water use efficiency
(WUE) and leaf total nitrogen content. Enhanced UV-B radiation significantly reduced leaf area (50.1%) but increased leaf
total nitrogen content (102%). These changes were associated with a decrease in stomatal conductance (16.1%) and intercellular
CO2 concentration/ air CO2 concentration (C
i
/C
a) (4.0%), and an increase in leaf tissue δ
13C (20.5‰), leaf water content (3.1%), specific leaf weight (SLW) (5.2%) and WUE (4.1%). The effects of UV-B on the plant were
greatly affected by the water content of the deep soil (30–40 cm). During the dry season, differences in the stomatal conductance,
δ
13C, and WUE between the control and UV-B treated shrubs were very small; whereas, differences became much greater when soil
water stress disappeared. Furthermore, the effects of UV-B became much less significant as the treatment period progressed
over the three growing seasons. Correlation analysis showed that enhanced UV-B radiation decreased the strength of the correlation
between soil water content and leaf water content, δ
13C, C
i/C
a, stomatal conductance, with the exception of WUE that had a significant correlation coefficient with soil water content.
These results suggest that WUE would become more sensitive to soil water variation due to UV-B radiation. Based on this experiment,
it was found that enhanced UV-B radiation had much more significant effects on morphological traits and growth of S. pubescens than hydro-physiological characteristics.
__________
Translated from Journal of Plant Ecology, 2006, 30(1): 47–56 [译自: 植物生态学报] 相似文献