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中国高等学校学术文摘·林学
中国高等学校学术文摘·林学

沈国舫

季刊

1673-3517

100029

北京市朝阳区惠新东街4号富盛大厦15层

中国高等学校学术文摘·林学/Journal Frontiers of Forestry in China
查看更多>>涉及领域包括森林生态、森林培育学、森林经理、自然保护区学、林木遗传育种、森林植物学、林木生理学、森林病虫害防治、森林资源信息管理、水土保持科学、林业经济管理、木材科学与技术、林产化工及其他相关学科。
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    Plant roots and anti-scourability of soils in the Shangshe Catchment, Dabie Mountains, Anhui Province, Eastern China

    Jiayao ZHUANGJinchi ZHANGBo ZHANGHongyan LUO...
    323-329页
    查看更多>>摘要:The distribution of root biomass was studied in different soil layers (0-10, 10-20, 20-30, 30-40 cm) by means of a "study plot" method for various plant species in the Shangshe Catchment area in the Dabie Mountains, Anhui Province. The number and lengths of root samples were recorded. In each study plot, anti-scourability of soils in corresponding soil layers was measured with a C.C. Suoboliefu anti-scourability instrument. The results showed the following: 1) The root system was largely distributed in the 0-40 cm soil layer and the number of roots was the largest in the surface soil layer. Fine roots < 1 mm in diameter predominated in root length. 2) In the same section, the anti-scourability indices of the surface soil layer were larger than those of other soil layers in the various plant species. The tree root system, especially the fine roots < 1 mm in diameter, are highly instrumental in controlling soil losses. Correlation coefficients of length, number and density of fine roots and the anti-scourability index were 0.8173, 0.7159 and 0.6434, respectively. The length of fine root is a key factor in the anti-scourability soil index. This index is closely correlated with the non-capillarity of each soil type, indicating that forests have a strong soil stabilizing function, because their root systems improve physical soil properties and ultimately are responsible for the establishment of a biosoil system with an anti-scourability index.

    Characteristics of soil water consumption of typical shrubs (Caragana microphylla) and trees (Pinus sylvestris) in the Horqin Sandy Land area, China

    AlamusaDeming JIANG
    330-337页
    查看更多>>摘要:Reforestation is one of the most effective ways to reduce the impacts of desertification. Caragana microphylla Lam. and Pinus sylvestris var. mongolica Litrin have been widely used to stabilize shifting sands in the Horqin sandy land area since the 1980s. However, soil water depletion has been of major concern in C. microphylla and P. ongolica plantations and in many places current soil moisture cannot meet the demand of growing plants. To determine the water budget of C. microphylla and P. mongolica plantations, we studied the effect of plantations on soil moisture and assessed the evapotranspiration in plantations of both species. Investigations were conducted at a fenced plot at Wulanaodu (42°29′N, 119°30′E, 479 m a. s. 1), located at the western edge of the Horqin Sandy Land area in Inner Mongolia, northern China. Five year old C. microphylla and seven year old P. mongolica plants were selected from the plantations and transplanted to iron boxes (400cm× 200cm×120cm) which can drain extra water. Plant spacing of 1 m×1 m was applied to P. mongolica, and two plant spacings of 1 m×1m and 1 m×2m to C. microphylla. The transplanted plants grew for two years in the boxes. Soil moisture from soil surface to a depth 80 cm were measured at 20 cm intervals in boxes every 10 d (2004) or 3 d (2005) during the growing season with a TDR water meter. The evapotranspiration was estimated from a mathematical formula and the characteristics of soil water consumption and evapotranspiration of these two plantations were analyzed. The soil water of P. mongolica was more than that ofC. microphylla at the same 1 m×1 m spacing. The soil water of C. microphylla with the 1 m× 2 m spacing was more than that of the 1 m ×1 m spacing. The evapotranspiration ranged from high to low as follows: C. microphylla (1 m×1 m), C. microphylla (1 m×2m) and P. mongolica (1 m×1 m) during the growing seasons. The evapotranspiration of individual plants ranging from high to low was C. microphylla (1 m×2 m), C. microphylla (1 m×1 m), and P. mongolica (1 m×1m) during the growing season. C. microphylla grown for five year consumed more water than P. mongolica grown for seven years at the same spacing.

    Infiltration characteristics of water in forest soils in the Simian mountains, Chongqing City, southwestern China

    Wei WANGHongjiang ZHANGMeng LIJinhua CHENG...
    338-343页
    查看更多>>摘要:Spearman rank-correlation analysis and grey relational grade analysis were used to study infiltration characteristics of water in different forest soils in the Simian mountains, Chongqing City. The results indicate that the soil bulk density, contents of coarse sand, and porosity of macropores were significantly correlated with saturated hydraulic conductivity. Porosity of macropores and contents of coarse sand were positively correlated with soil saturated hydraulic conductivity and soil bulk density negatively. Based on the initial infiltration rate, the stable infiltration rate, time required for infiltration to reach a stable state, and cumulative infiltration, all of which are crucial parameters determining soil infiltration capacity, the results of grey relational grade analysis showed that the grey relational grades of the different forest soils were listed from high to low as broad-leaved forest (0.8031) > Phyllostachys pubescens forest (0.7869) > mixed coniferbroadleaf forest (0.4454)>coniferous forest (0.4039). Broadleaf forest had the best ability to be infiltrated among the four soils studied. The square roots of the coefficients of determination obtained from fitting the Horton infiltration equation, simulated in our study of forest soils, were higher than 0.950. We conclude that soils of broad-leaved forests were the best suited for infiltration processes of forestry in the Simian mountains.

    Features of soil enzyme activities and the number of microorganisms in plantations and their relationships with soil nutrients in the Qinling Mountains,. China

    Gang FUZengwen LIUFangfang CUI
    344-350页
    查看更多>>摘要:We studied the distribution of soil nutrients, the number of soil microorganisms, soil enzyme activities, and their relationships in pure and mixed plantations. Soil enzyme activities, the number of soil microorganisms, and soil nutrients were measured in plantations of Chinese pine (Pinustabulaeformis), larch (Larix kaempferi), sharp tooth oak (Quercus aliena var. acuteserrata), Manchurian catalpa (Catalpa fargesii), and mixed plantations in the Qinling Mountains, China. Compared with pure plantations, the conifer-broad-leaved broadleaf mixed plantations increased total N, available N, total P, available K, and organic matter in the forest soil; promoted the activities ofinvertase and urease by 16.7% and 53.8%; and increased the total amount of soil microorganisms by 95.9% and the number of bacteria by 104.5% (p<0.05). The correlations between soil enzymes, number of microorganisms, and soil nutrients were significant(p<0.05), and the correlations between the number of soil bacteria and basic nutrient prosperities (total N, available N, available K, and organic matter (OM)) were significant or highly significant. The correlations between the number of soil actinomycetes, and soil total N, available N, OM, and pH were also significant or highly significant. A suitable mixture of planted conifers and broad-leaved species improves the quality and amount of soil nutrients, increases the number of soil microorganisms and changes their redistribution. The change of soil enzymes and the number of soil microorganisms are indications of the change tendency of soil nutrients.

    Characteristics of leaf areas of plantations in semiarid hills and gully loess regions

    Jing YINFan HEGuoyu QIUKangning HE...
    351-357页
    查看更多>>摘要:The objectives of our study were to explore the relationship of leaf area and stand density and to find a convenient way to measure stand leaf areas. During the 2004 growing season, from May to October, we used direct and indirect methods to measure the seasonal variation of the leaf areas of tree and shrub species. The trees were from Robinia pseudoacacia stands of four densities (3333 plants/hm2, 1666 plants/hm2, 1111 plants/hm2, and 833 plants/hm2) and Platycladus orientalis stands of three densities (3333 plants/hm2, 1666 plants/hm2, and 1111 plants/hm2). The shrub species were Caragana korshinskii, Hippophae rhamnoides, and Amorpha fruticosa. Based on our survey data, empirical formulas for calculating leaf area were obtained by correlating leaf fresh weight, diameter of base branches, and leaf areas. Our results show the following: 1) in September, the leaf area and leaf area index (LAI) of trees (R. pseudoacacia and P orientalis) reached their maximum values, with LAI peak values of 10.5 and 3.2, respectively. In August, the leaf area and LAI of shrubs (C. korshinskii, H. rhamnoides, and A. fruticosa) reached their maximum values, with LAI peak values of 1.195, 1.123, and 1.882, respectively. 2) There is a statistically significant power relation between leaf area and leaf fresh weight for R. pseudoacacia. There are significant linear relationships between leaf area and leaf fresh weight for P. orientalis, C. korshinskii, H. rhamnoides, and A. fruticosa. Moreover, there is also a significant power relation between leaf area and diameter of base branches for C. korshinskii. There are significant linear relations between leaf area and diameter of base branches of H. rhamnoides and A. fruticosa. 3) In the hills and gully regions of the Loess Plateau, the LAIs of R. pseudoacacia stand at different densities converged after the planted stands entered their fast growth stage. Their LAI do not seem to be affected by its initial and current density. The same is true for P. orientalis stands. However, the leaf area of individual trees is negatively and linearly related with stand density. We conclude that, in the hills and gully regions of the Loess Plateau , the bearing capacity of R. pseudoacacia and P. orientalis stands we studied have reached their maximum limitation, owing to restricted access to soil water. Therefore, in consideration of improving the quality of single trees, a stand density not exceeding 833 and 1111 plants/hm2 is recommended for R, pseudoacacia and P orientalis, respectively. In consideration of improving the quality of the entire stands, the density can be reduced even a little more.

    Application of PDA forest fire monitoring based on web service technology

    Yufei ZHOUPengju LIUXiaoming TANG
    358-362页
    查看更多>>摘要:The difficulty in information communication and sharing are major problems for forest fire monitoring and early warning in China. As authors, we applied web service technology to a personal digital assistant (PDA) forest fire monitoring system and propose the framework of a monitoring system based on service-oriented architecture (SOA). At the same time, we describe the composition and function of web services from a server side and a client side. The method for developing a web service invocation engine on the PDA is introduced in detail. Finally, an example of a fire danger rating and fire weather services system are established, based on the Beijing Forest Fire Control System. The results show that the PDA forest fire monitoring system based on web services can effectively take advantage of the existing fire protection decision information services, realize real-time information interaction and sharing, and improve the level of forest fire monitoring.

    Remote sensing monitoring of a bamboo forest based on BP neural network

    Yongjun SHIXiaojun XUHuaqiang DUGuomo ZHOU...
    363-367页
    查看更多>>摘要:The collection of information on bamboo forests plays a crucial role in the calculation of carbon content reserves, and the acquisition of high-precision information will be good for reducing estimation errors. High precision is obtained with the adoption of a back propagation (BP) neural network to extract information on bamboo forests from Enhanced Thematic Mapper + (ETM +) remote sensing images with the assistance of neural network modules provided by Matlab. We obtained a production precision of 84.04% and a user precision of 98.75%. We also conducted a comparison of classification differences of three training functions, i.e., the, LevenbergMarquardt BP algorithm function (Trainlm), a gradient decreasing function of adaptive learning rate BP (Traingda), and a gradient lowering momentum BP algorithm function (Traingdm). Our analysis suggests that Traingda had the highest precision while Trainlm function required the shortest training time.

    Prediction of mechanical properties of Chinese fir wood by near infrared spectroscopy

    Huaqiang YURongjun ZHAOFeng FUBenhua FEI...
    368-373页
    查看更多>>摘要:Mechanical properties and the visible and near infrared (NIR) (350-2500nm) spectra obtained from longitudinal and transverse face of 155 small clear wood samples of Chinese fir (Cunninghamia lanceolata) were measured, and 103 of them were used to establish calibration models. Calibrations were tested on an independent set (52 samples). Differences between calibrations developed by using the longitudinal and transverse face were small. The calibrations developed by using NIR spectra (350-2500nm) collected from transverse face were slightly inferior to those developed by using NIR spectra collected from longitudinal face. When reducing the spectral range to between 780 and 1050 nm, the calibrations developed by using NIR spectra collected from longitudinal face were slightly inferior to those developed by using NIR spectra collected from transverse face, and reducing the spectral range causes no decrease in the quality of the models developed using NIR spectra collected from transverse face. Partial lease square (PLS) modeling and test showed that calibrations developed using the visible and NIR spectra from transverse and longitudinal faces and calibrations developed by using the reducing spectral range (780- 1050nm) from the transverse face were moderate, and have a RPD range from 1.51 to 1.90. It is concluded that NIR spectroscopy can be used as an initial screening.

    Dynamic viscoelastic behavior of wood under drying conditions

    Jiali JIANGJianxiong LU
    374-379页
    查看更多>>摘要:In this study heartwood from a Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] plantation was treated using a high-temperature drying (HTD) method at 115℃, a low-temperature drying (LTD) method at 65℃, and freeze vacuum drying (FVD), respectively. The dynamic viscoelastic properties of dried wood specimens were investigated. The measurements were carried out at a temperature range of -120 to 250℃ at four different frequencies (1, 2, 5, and 10 Hz) using dynamic mechanical analysis (DMA). We have drawn the following conclusions: 1) the storage modulus E' and loss modulus E" are the highest for HTD wood and the lowest for FVD wood; 2) three relaxation processes were detected in HTD and LTD wood, attributed to the micro-Brownian motion of cell wall polymers in the non-crystalline region, the oscillations of the torso of cell wall polymers, and the motions of the methyl groups of cell wall polymers in the non-crystalline region in a decreasing order of temperatures at which they occurred; and 3) in FVD wood, four relaxation processes were observed. A newly added relaxation is attributed to the micro-Brownian motions of lignin molecules. This study suggests that both the HTD and the LTD methods restrict the micro-Brownian motion of lignin molecules somewhat by the cross-linking of chains due to their heating history.

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