共查询到20条相似文献,搜索用时 15 毫秒
1.
This study evaluated the protection effectiveness of alcohol-borne reagents for the green color of ma bamboo (Dendrocalamus latiflorus Munro) and moso bamboo (Phyllostachys pubescens Mazel). The results show that the types and concentrations of alcohol-borne reagents, the kinds of solvent, and the conditions
of treatment greatly affected the green color of these two bamboo species. Without alkali pretreatment, an excellent green
color protection (a* = −14.5) was obtained when the ma bamboo culms were treated with 0.5% methanol-borne copper chloride (CuCl2) at 60°C for 30 min. Similar results were also obtained when ma bamboo culms were treated with 0.5% methanol-borne copper
nitrate [Cu(NO3)2] at 60°C for 2 h (a* = −13.5). For moso bamboo, an attractive green color in the bamboo culms was achieved by treating the specimens with 1%
methanol-borne copper acetate [Cu(CH3COO)2] at 60°C for 30 min. The a* value of treated specimens was −13.3. In addition, results demonstrated that ultrasonic treatment was more effective on
green color protection than conventional water bath treatment. When moso bamboo was treated with 1% copper acetate at 60°C
in an ultrasonic bath for only 15 min, a remarkable green color with an a* value of −13.6 was obtained on the bamboo epidermis. 相似文献
2.
We derive a two-way volume equation for estimating the apparent culm volume of one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houz. The volume equation was derived from the assumptions that (1) the relative culm form can be expressed by Kunze’s
equation and (2) normal form-factors at two different relative heights are steady at constants independent of culm sizes.
A total number of 200 sample culms were collected from a stand of P. pubescens in Mt. Toshima, Kumamoto Prefecture, western Japan, and were randomly bisected into two sets of data, i.e. modeling and test
data. For the modeling data, normal form-factors at 0.6 and 0.9 in relative height were steady at 0.908 and 0.448, respectively.
The coefficients of the volume equation were determined based on these steady values of the normal form-factors. For the test
data, the apparent culm volume was estimated from diameter at breast height and culm height with the determined volume equation.
The mean error and root mean square error of the estimated culm volume were, respectively, 8.120 × 10−5 and 3.291 × 10−3 m3, and there was no significant difference between estimated and actual volume. In conclusion, the two-way volume equation
presented here appears to be convenient for predicting the apparent culm volume for P. pubescens. 相似文献
3.
Juan Carlos Camargo García Christoph Kleinn 《European Journal of Forest Research》2010,129(6):1213-1222
Three models for the prediction of bamboo culm length and two for culm volume were fitted from data of 303 guadua bamboo (Guadua angustifolia Kunth) culms. Data are from 101 temporary inventory plots systematically distributed over the coffee region of Colombia (inventory
area about 1,029,525 ha). Linear and non-linear regression models were used, and the precision of the models was evaluated
by cross-validation. The models were compared by studying the adjusted coefficient of determination, the bias, mean square
error and Akaike’s information criterion and by the F-test that compares predicted and observed values. For culm length, the best fit showed models that included predictor variables
related to stand characteristics such as quadratic mean diameter and number of culms per ha. For culm volume prediction, the
inclusion of culm length improved the model significantly. For the simple form factor model, precision of prediction was least.
The models developed are useful in facilitating the estimation of stand characteristics that are relevant for the silvicultural
management of Guadua stands and also for the assessment of their environmental services (such as carbon sequestration). 相似文献
4.
This study tries to clarify the conflicting results from previous studies on cell wall thickening in bamboo culms by applying light and transmission electron microscopy in combination with image analysis. It focused on both fibre and parenchyma wall thickness of both temperate (Phyllostachys spp.) and tropical (Gigantochloa levis and Dendrocalamus asper) bamboo species of different ages in the light of their suitability for the wood industry. The observations indicated a great heterogeneity in cell wall thickness and cell wall layering pattern of fibres within one culm. Nested design ANOVA’s revealed a rising trend in wall thickness of late maturing fibres and parenchyma cells during the first year but significant wall thickening during later years could not be demonstrated. The high variability within one culm and between culms of the same age from 1 year on is partly masking a clear increased cell wall thickening at higher age. Nevertheless, the highest mean values for fibre wall thickness were recorded in culms of 44 months old or older, suggesting that some kind of late cell wall maturing can take place within one culm. 相似文献
5.
正早竹(Phyllostachys praecox C.D.Chu et C.S.Chao)别名早园竹(浙江德清),属禾本科(Gramineae)刚竹属(Phyllostachys Sieb.et Zucc)刚竹组(Sect.Phyllostachys),产于我国江苏、安徽、浙江、江西、湖南、福建等省[1-3]。早竹因其笋期早、产量高、笋味美,而成为我国南方的重要笋用竹种[1]。据统计,我国南方早竹的种植面积在6.7万hm2以上,年产值达10亿多元[4]。然而,随着早竹大面积的推广种植和新的生产经营方式的推广应用,早竹遭受造瘿昆虫的严重危害。在部分严重危害的地块,有虫株率 相似文献
6.
F. Lalnunmawia 《林业研究》2008,19(2):148-150
A study was conducted to investigate culms density and size, seed size and production rate in Melocanna baccifera stands disturbed by biotic pressure and fire. Results revealed that culms density, number and size of seeds produced in the bamboo stands were significantly affected by frequent fire and excessive biotic pressure (collection of young shoots for vegetables and mature culms). The culm density and seed production rate decreased significantly in the stand subjected to excessive biotic pressure. An increasing exposure of culms to sun light was responsible for the above decrease. Seed production rate significantly increased in case of culms subjected to fire in comparison to the control. It indicated that fire stimulated the seed production in M. baccifera stand. 相似文献
7.
Professor King-Tsuen Wu 《Wood Science and Technology》1992,26(4):271-277
Summary The anatomical structure of bamboo culm is governed by the number, arrangement, shape and size of the vascular bundles. The vascular bundles at the peripheral zone of the culm are small and numerous, while those of the inner part are larger in size and smaller in number. No radial cell elements are present in the culm. Due to these peculiar structures, bamboo culms are susceptible to splitting during seasoning.This problem has been overcome by applying a high-temperature drying technique.When makino bamboo (Phyllostachys makinoi Hay.) culms were dried under elevated temperatures (from 60 °C up to 120 °C), no splits occurred on the culm surface. This phenomenon is explained by chemical composition analysis, mechanical properties associated with physical changes, scanning electron microscope and x-ray diffractometer observations.This paper was presented as a poster at the XIXth IUFRO World Congress in Montreal, Canada, August 1990. The author wishes to express his great appreciation to Dr. F. Tanaka of Wood Research Institute, Kyoto Univ., for the crystallinity determination. Thanks are given to the Government Industrial Research Institute, Osaka, Japan, for providing the x-ray diffractometer, and the National Science Council of Republic of China for supporting a 3-month leave at Wood Research Institute, Kyoto University 相似文献
8.
The objective of this study was to find an effective method for treating ma bamboo (Dendrocalamus latiflorus) and moso bamboo (Phyllostachys pubescens) using new water-based reagents containing copper. The effects of green-color protection using various treatments on bamboo
culms were examined in this study. Two methods were used: heating in a water bath and ultrasonic dipping. The results revealed
that excellent green-color protection (a* value of −6.2) was obtained when ma bamboo culms were treated with 0.25% ammoniacal copper quaternary compound-type B (ACQ-B)
in a water bath at 100°C for 2 h. It was also found that the wettability of bamboo epidermis increasedsignificantly after
pretreatment in a mixture of 1% KOH and surfactant in a water bath at 100°C for 30 min. Furthermore, pretreated moso bamboo
culms exhibited excellent green-color protection after they were treated with 0.25% ACQ-B at 100°C for 2 h (a* value of −8.2). This novel treatment method definitely endows the bamboo culms with a fascinating green skin color and consequently
could increase the economic value of bamboo products. No improvement in green-color protection was found when ultrasonic energy
was added to the water bath at ambient temperature. 相似文献
9.
[目的]揭示屏边空竹的发笋、退笋和幼竹生长规律。[方法]定点观测了30丛屏边空竹周年的出笋、退笋、秆高及地径生长数据,运用SPSS软件分析评价了不同季节出笋及幼竹生长规律。[结果](1)屏边空竹笋期历时9个月左右(从9月至次年5月),根据出笋量的差异可分为初期、盛期和末期,春季最多而夏季最少;其中5丛(16. 67%)每季出笋,具有四季发笋的习性。(2)退笋率随着笋期逐渐增加,在出笋末期达到最高,为87. 76%。(3)笋-幼竹高生长约130 d完成,平均秆高达6. 36 m;呈现"慢-快-慢"的生长规律,生长曲线可用三次曲线方程描述:H=0. 806-0. 029t+0. 001t2-5. 894×10-6t3,R2=0. 980。(4)地径的生长历时16 d左右,平均地径为18. 50 mm,也呈现"慢-快-慢"的生长规律。[结论]屏边空竹发笋期长约9个月,具有四季发笋的习性,但各季节出笋量差异显著;秆高和地径呈现"慢-快-慢"的生长规律。 相似文献
10.
Schizostachyum dullooa (Gamble) Majumder ‘dolu bamboo’ is a thin walled sympodial moderate sized to large tufted bamboo, dominant in the successional fallows of northeast India.
The impact of resource management on productivity and sustainability of the species was evaluated by investigating the population
status and regeneration in Cachar tropical semi evergreen forest under private property resource management (PPRM) and common
property resource management (CPRM) regimes. Population status revealed current-year, one-year, two-year and three-year-old
culms contribute 54%, 24%, 16% and 6% of the total culms per clump, respectively, under PPRM. Three-year-old culms were absent
in CPRM and population status was thus represented by current year (83%), one-year (16%) and two-year (1%) old culms. Net
change, rate of change and % gain in population for different age classes showed the prevalence of management practices under
CPRM was unscientific. Efficiency of new culm production per clump used as an index of regeneration was 69.7% in PPRM and
59.88% in CPRM. New culms produced under CPRM were small and thin. We conclude that CPRM is inappropriate for a long term
economic and ecological sustainability of the species and alternative management protocols are needed for conservation of
the species. 相似文献
11.
C. A. Raymond L. R. Schimleck A. Muneri A. J. Michell 《Wood Science and Technology》2001,35(3):203-215
Within-tree variation in kraft pulp yield, predicted using near infrared reflectance analysis, was studied in thirty trees
of E. globulus and fifty trees of E. nitens to develop a non-destructive sampling strategy. Trees, aged 5 to 9 years, were sampled across a range of sites in southern
Australia. Simulated core samples were removed at six fixed heights easily accessible from the ground (0.5, 0.7, ... 1.5 m)
and at seven percentage heights (0, 20, 30, ... 70%). Whole-tree values, calculated from percentage height data, were correlated
with the core data to determine the optimal sampling height. Core samples were found to be good predictors of whole-tree pulp
yield for E. globulus, with simulated cores taken from the recommended sampling height (1.1 m) explaining more than 50% of variation in whole-tree
pulp yield. Results for E. nitens were variable with large site differences apparent. On high quality sites, core samples from the recommended sampling height
(0.9 m) were good predictors of whole-tree pulp yield, explaining around 60% of the variation. On poor quality sites, cores
were poor predictors of whole-tree pulp yield. Radial orientation of cores was not important and predicted pulp yield was
not related to tree size, basic density or fibre length. To estimate stand mean pulp yield to an accuracy of ±1% would require
sampling 6 trees of E. globulus and 4 trees for E. nitens using either multiple discs or core samples. A single sampling height (1.1 m) is recommended for sampling for basic density,
fibre length, fibre coarseness and predicted pulp yield in E. globulus. For E. nitens the recommended sampling height for basic density and fibre length is 0.7 m and 0.9 m is recommended for predicted pulp yield
on good quality sites.
Received 17 September 1998 相似文献
12.
A. Itoh T. Yamakura S. Tan J. J. Kendawang H. S. Lee 《Journal of Forest Research》2003,8(2):0117-0121
Cuttings from older trees of the Dipterocarpaceae generally lose their ability to root. However, branches in a canopy of
adult dipterocarps are a possible source of cuttings because they show juvenile characteristics in architecture due to “adaptive
reiteration”, suggesting physiological rejuvenation. Effects of resource plant size on the rooting of cuttings and the possibility
of using cuttings from reiterated branches of adult trees were studied for Dryobalanops lanceolata, an emergent dipterocarp species. A cutting experiment with non-mist propagators was conducted for cuttings collected from
resource plants of four different size classes: <2 m, 2–5 m, 8–15 m, and 70 m in height. The smallest size class included
two different age classes: <2 and >2 years old. Cuttings from the tallest resource plant were collected from reiterated branches.
Rooting percentage was negatively correlated with resource plant size: 77–78% for resource plants <2 m, 63% for 2–5 m, 36%
for 8–15 m, and 0% for 70 m. Rooting percentages of cuttings collected from different individuals were not different for the
2–5 m tall class, while they were significantly different for the 8–15 m tall class. Resource plant size was negatively correlated
with the number of roots for rooted cuttings. No significant relationship was observed between resource plant size and mean
length of each root, total root length or total root dry weight for rooted cuttings. The results suggest the possibility of
collecting cuttings from relatively large resource plants up to 15 m tall and >20 years old if we chose good individuals for
resource plants. The results, however, show the difficulty in using reiterated branches of adult trees as a source of cuttings
for D. lanceolata.
Received: October 15, 2001 / Accepted: November 11, 2002
Acknowledgments We express our sincere thanks to Dr. S. Tamura, Dr. K. Ogino, and Mr. A.A. Hamid for their kind support. The tree tower was
constructed in a cooperative project between Japan and Sarawak supported by the Ministry of Education, Culture, Sports, Science
and Technology, Japan (Grant NP0201). The cutting experiment was partly funded by the Nippon Life Insurance Foundation and
the Japan Society for the Promotion of Science (JSPS-RFTF96R16001).
Correspondence to:A. Itoh 相似文献
13.
We determine the relationships of culm surface area to other culm dimensions for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houzeau de Lehaie. A total number of 150 sample culms were collected from a stand of P. pubescens in Mt. Toshima, Kumamoto Prefecture, western Japan. The culm surface area for each sample was calculated, and then the relationships
of the culm surface area to basal area and product of diameter at breast height (dbh) and culm height were analyzed. The relationship
between culm surface area and basal area could be described successfully by the power equation, whereas there was a linear
relationship of culm surface area to product of dbh and height. Although the regression equations determined here would be
useful in estimating culm surface area of P. pubescens, it is necessary to select an appropriate equation depending on the purpose and available time and labor. 相似文献
14.
The bambooPhyllostachys bambusoides has been widely planted on riverbanks in Japan to protect against erosion. Recently, unmanagedP. bambusoides stands with high culm density are spreading along the banks of rivers. In order to study the impact of the bamboo stands
on riparian ecosystems, the relations between bamboo stand structure, light conditions and plant communities under the canopy
were examined. The study sites were set in bamboo stands with various culm densities in the middle of the Yahagi River in
Toyota, Aichi Prefecture. There was a close relationship between canopy coverage and relative photon flux density (RPFD) in
the bamboo stands. RPFD showed a highly negative relationship with total culm density, whereas no significant relation was
observed between the basal area of bamboo and RPFD. The total number of plant species in the bamboo stands increased with
decreasing culm density. Only a small number of tree saplings were observed in the stands with the highest culm densities,
while several species of forest floor herbs were found in the stands with lower culm densities. A number of invasive and annual
plants colonized the thinned stand. We suggest that moderate thinning and clearing of dead culms are needed to maintain biological
diversity in the bamboo stands on riverbanks. 相似文献
15.
We used thermal images of bamboo culms of Guadua angustifolia Kunth to analyze the relationship between culm surface temperature and maturity, driven by the hypothesis that young culms may exhibit lower surface temperatures than old ones. The culm surface temperature shows small but constant differences between three age classes of 1, 2, and 3 years. Our findings indicate that surface temperature may be applied as an additional indicator to support the determination of maturity of guadua culms besides the visual assessment of the culms. 相似文献
16.
Using 3-year-old culms of 8 provenances of Bambusa chungii from Guangdong, Guangxi and Hainan Provinces, the indexes of wood properties, such as fiber dimensions and chemical composition
were investigated and analyzed by the methods of Analysis of variance and correlation coefficient to reveal the geographic
genetic variation situation. The results showed that there are significant differences between fiber length, fibrin and 1%
NaOH extraction contents of B. chungii from 8 provenances; moreover, the fiber length and fiber length/width ratio had a decreasing change pattern with geographic
variation from the south to the north in altitude (from high to low in elevation). The heritabilities for fibrin, fiber length,
1% NaOH extractive, lignin and fiber length/width ratio were 0.7, 0.84, 0.54, 0.38 and 0.13, respectively. A significant negative
correlation was found between 1% NaOH extraction, benzo-alcohol extraction contents and bamboo culm yield, whereas there was
a significant positive correlation between fibrin contents and bamboo wood yield. Besides, a close correlation was detected
between fiber dimensions indices and bamboo growth or bamboo wood yield. Finally, three provenances with high qualities and
culm yield, i.e. Huaiji, Xinyi and Guilin, were selected as superior sources based on principal component analysis.
Foundation project: This research was funded by both of the International Tropical Timber Organization (ITTO), grant No. PD10/00.
REV. 2 (I,F), and the National ‘Tenth Five-year’ Key Program of China, grant No. 2004BA506B0103. 相似文献
17.
The effects of removing aboveground vegetation on survival and growth of Hondo spruce (Picea jezoensis var. hondoensis) saplings were examined in a dense dwarf bamboo (Sasa nipponica) field inside a deer-proof fence built in a degraded sub-alpine forest on Mt Ohdaigahara, central Japan. All bamboo culms
were removed within a radius of 1 m from each sapling in a plot of 0.6 ha (removal plot), whereas no culms were removed in
two control plots of 0.1 ha. We measured the height, crown depth, and main shoot elongation over 1 year for all spruce saplings,
culm height and cover ratios of dwarf bamboo growing around each spruce sapling, and the light levels above each sapling.
Removal of dwarf bamboo regulated the culm height and bamboo coverage until the following summer such that light conditions
improved. The mortality of saplings smaller than the average culm height was lower in the removal plot (0.89%) than in a control
plot (5.9%). After bamboo removal, sapling height growth was reduced with increasing bamboo cover in the previous year. Complete
removal of the aboveground portions of covering bamboo improved sapling survival while regulating elongation growth, possibly
because of the sudden increase in light intensity. Thus, controlling the extent of dwarf bamboo removal might be necessary
to facilitate the growth of spruce saplings to restore the forest. 相似文献
18.
A non-destructive sampling strategy for basic density, based on removing 12 mm bark-to-bark cores, was developed in E. globulus and E. nitens. Fifty trees of each species, aged 5 to 9 years, were sampled across a range of sites. Core samples were removed on both
a north-south and an east-west axis from 6 fixed heights in the base of the tree (0.5 m, 0.7 m, …, 1.5 m). Whole-tree values
were calculated from disc samples removed at eight percentage heights (0, 10, 20, …, 70%) and correlations between the cores
and whole-tree values were used to determine the optimal sampling height. Core samples were found to be reliable predictors
of whole-tree density, explaining between 84% and 89% of the variation between trees. Core sampling of E. globulus and E. nitens to estimate basic density of whole-trees and stands is feasible; cores from trees at all E. globulus sites gave high correlations with whole-tree values. For E. nitens, site differences were apparent, and it is recommended that a small destructive sampling program should be undertaken prior
to commencing a major sampling program. Recommended optimal sampling heights are 1.1 m for E. globulus and 0.7 m for E. nitens. Core orientation was not important and density was not related to tree size. Six whole-tree samples or eight core samples
are required for estimating the mean density of a stand at a specific site to an accuracy of ±20 kg m−3 with a 95% confidence interval.
Received 17 September 1998 相似文献
19.
Experimental results were studied to determine the relationships between positioning precision of a differential global positioning
system (DGPS) and forest type, antenna height, and season, and to clarify the relationship between sampling number and the
convergence of positioning precision. Observation was carried out for 24 h. Mean circular area probability (CEP95) was 2.80 m for deciduous broadleaved trees, and 4.99 m for conifers. The mean CEP95 taken at 7 m height (3.14 m) was higher than that at 1 m height (3.92 m) at all sites. The mean CEP95 taken during the defoliation season (2.65 m) was slightly better than during the foliation season (2.96 m). There were significant
differences between forest types (P < 0.001) and antenna heights (P < 0.05). Positioning precision was not noticeably improved if the sampling number was around ten or less. A sampling number
of 100–1000 or more is required before substantial improvements can be expected. As long as high positioning precision is
not required, it is acceptable to use 2D & 3D modes and relatively few samples to take measurements.
Received: April 24, 2002 / Accepted: October 10, 2002
Correspondence to:I. Sawaguchi 相似文献
20.
《林业研究》2019,(6)
The hollow cylindrical culm is one of the most remarkable morphological characters of most bamboo species. In relation to its hollow structure, there are two different attributes of the culm volume in bamboo: the apparent culm volume(v_a: the total culm volume including the hollow portion) and the woody culm volume(v_w: the volume of the woody walls of the culm). The ratio of v_w to v_a is defined as the reduction factor for culm volume(f_v).The quantity f_v is useful to quantify the biomass resources of bamboo culms as well as to evaluate the carbon stock of bamboo forests. However, the direct measurement of f_v requires destructive sampling, which consumes time and labor. Hence, an alternative method for obtaining f_v is desired. In this study, we examined f_v in five species of the genus Phyllostachys and proposed alternative methods to estimate f_v. Our data showed that f_v varied by species, some of which exhibited a dependency of f_v on culm sizes. These findings indicate that the intraspecific and interspecific variation in f_v should be considered carefully when converting v_a into v_w by f_v. Based on our results, we propose here six approaches for predicting f_v and we discuss their advantages and disadvantages. Our results are intended to facilitate evaluation of the carbon sequestration capacity of bamboo forests and the commercial utilization of bamboo culms. 相似文献