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Journal of Hydrodynamics 2013年第6期25卷 877-885页

作者：张会兰王玉杰王云琦李丹勋王兴奎 key laboratory of soil and water conservation and desertification combating Ministry of EducationDepartment of Soil and Water ConservationBeijing Forestry University State key laboratory of Hydroscience and Engineering Tsinghua University key laboratory of soil and water conservation and desertification combating Ministry of EducationSchool of Soil and Water ConservationBeijing Forestry University

To investigate the performance of fully- and semi-distributed hydrologic models in simulating the process of transformation from rainfall to runoff in mountain areas, the fully-distributed models Basin Pollution Calculation Center （BPCC） and HEC- HMS are calibrated for the Zhenjiangguan watershed located in the upper stream of Minjiang River Southwest China using streamflow observations at the basin outlet. Semi-automatical optimization method is implemented to both models to improve simulated resuits by removing artificial errors. Based on the consistency of the simulated hydrographs with the observed ones, the statistical coefficients such as the relative error, the probability distribution and the correlation coefficient, are further introduced to evaluate quantitatively the performance of the two models. Analyses indicate that the hydrographs simulated by the BPCC are relatively closer to the observed ones than those simulated by the HEC-HMS in view of the spatial heterogeneity in terrain, soil texture, land cover and meteorological conditions in mountain areas.

关键词： Basin Pollution Calculation Center (BPCC) HEC-HMS hydrologic modeling mountain area semi-automaticallyoptimization

Land-use changes in the small watershed of the Loess Plateau,hilly-gully region, China

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Journal of Forestry Research 2015年第1期26卷 91-99页

作者： Yini Han Jianzhi Niu Feizhou Wu key laboratory of soil and water conservation & desertification combating Beijing Forestry University

As more and more farmland is converted to forestry, the need for effective decision support regarding the use of land in the fragile ecological environment of the Loess Plateau hilly-gully area. The Luoyugou watershed was chosen as the study area to calculate the single dynamic degree, integrated dynamic degree, and change indexes of land use, as well as the land-use type transition matrix. This was done by interpreting the TM and SPOT images of the Luoyugou watershed in 1986, 1995, and2004 and making statistical analysis. The results of ou statistical analysis show that the conversion of slope farm land to terrace and forest land plays a dominant role in land-use changes in the Luoyugou watershed from 1986 to2004. The land-use changes are mainly driven by popula tion growth, socio-economic development, consume spending, and investment in forest ecology.

关键词： Loess Plateau hilly-gully region Luoyugou watershed Land use and cover changes Driving force

Characteristics of run off and sediment generation of forest vegetationon a hill slope by use of artificial rainfall apparatus

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Journal of Forestry Research 2012年第3期23卷 419-424页

作者： LI Xiang NIU Jian-zhi LI Jiao XIE Bao-yuan HAN Yi-ni TAN Jing-ping ZHANG Ying-hu key laboratory of soil and water conservation&desertification combating Beijing Forestry UniversityBeijing 100083China

We studied the impact of forest vegetation on soil erosion, surface runoff, and sediment generation by using field simulated rainfall apparatus. We measured runoff and sediment generation of five 4.5 × 2.1 m runoff plots （a bare soil as a control; two Pinus tabulaeformis forest plots and two Platycladus orientalis forest with row spacing of 1 m × 1 m and 1.5 m× 1.5 m, respectively） in Beijing Jiu Feng National Forest Park under three rainfall intensities （0.42, 0.83, 1.26 mm per minute）. Forest vegetation significantly reduced soil erosion and sediment yield. Mean total runoff volume in the four tree stand plots was 93% of that in the control plot, demonstrating the limited effectiveness of forest vegeta- tion in runoff control. With increasing rainfall intensity, runoff reduction in forest plots declined from 28.32% to 2.1%. Similar trends in runoff coefficient and the relationship between runoffvolume and rainfall duration was observed. Mean total sediment yield and mean sediment yield reduction rate under different treatments was 55.05% and 43.17% of those in the bare soil control plot, respectively. Rainfall intensity played an important role in runoff and sediment generation processes, and had a greater impact on runoff than on soil erosion and sediment generation. When considering several factors in runoff and sediment transport processes, the P. tabulaeform plot with row spacing at 1 × 1 m had a greater effect on soil and water conservation than did other forested plots.

关键词： soil erosion forest vegetation rainfall intensity runoff sediment

Effects of plant roots on soil preferential pathways and soil matrix in forest ecosystems

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Journal of Forestry Research 2015年第2期26卷 397-404页

作者： Yinghu Zhang Jianzhi Niu Weili Zhu Xiaoqing Du Jiao Li key laboratory soil and water conservation and desertification combating Ministry of EducationCollege of Soil and Water ConservationBeijing Forestry University

To characterize effects of plant roots on preferential flow（PF）,we measured root length density（RLD）and root biomass（RB） in Jiufeng National Forest Park,Beijing,*** were made for RLD and RB between soil preferential pathways and soil *** and RB declined with the increasing soil depth（0–10,10–20,20–30,30–40,40–50,50–60 cm） in all experimental *** was greater in soil preferential pathways than in the surrounding soil matrix and was 69.5,75.0 and72.2 % for plant roots of diameter（d）／1,1 ／ d ／ 3 and3 ／ d ／ 5 mm,*** root systems had the most pivotal influence on soil preferential flow in this forest *** all experimental plots,RB content was the sum of RB from soil preferential pathways and the soil matrix in each soil *** respect to 6 soil depth gradient（0–10,10–20,20–30,30–40,40–50,50–60 cm） in each plot,the number of soil depth gradient that RB content was greater in soil preferential pathways than in the soil matrix was characterized,and the proportion was68.2 % in all plots.

关键词： Preferential flow Preferential pathways soil matrix Root length density Root biomass

Anchorage properties at the interface between soil and roots with branches

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Journal of Forestry Research 2017年第1期28卷 83-93页

作者： Xiaodong Ji Lihua Chen Ao Zhang key laboratory of soil and water conservation and desertification combating Ministry of Education of ChinaBeijing Forestry University100083 BeijingChina

Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.

关键词： Root-soil interface mechanics Pullout test method Root branches Branch angle

Vertical root distribution and root cohesion of typical tree species on the Loess Plateau, China

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Journal of Arid Land 2014年第5期6卷 601-611页

作者： ChaoBo ZHANG LiHua CHEN Jing JIANG College of water Resources Science and Engineering Taiyuan University of Technology key laboratory of soil and water conservation and combating desertification of Ministry of Education of China School ofWater and Soil Conservation Beijing Forestry University

Black locust（Robinia pseudoacacia L.） and Chinese pine（Pinus tabulaeformis Carr.） are two woody plants that are widely planted on the Loess Plateau for controlling soil erosion and land desertification. In this study, we conducted an excavation experiment in 2008 to investigate the overall vertical root distribution characteristics of black locust and Chinese pine. We also performed triaxial compression tests to evaluate the root cohesion（additional soil cohesion increased by roots） of black locust. Two types of root distribution, namely, vertical root（VR） and horizontal root（HR）, were used as samples and tested under four soil water content（SWC） conditions（12.7%, 15.0%, 18.0% and 20.0%, respectively）. Results showed that the root lengths of the two species were mainly concentrated in the root diameter of 5–20 mm. A comparison of root distribution between the two species indicated that the root length of black locust was significantly greater than that of Chinese pine in nearly all root diameters, although the black locust used in the comparison was 10 years younger than the Chinese pine. Root biomass was also significantly greater in black locust than in Chinese pine, particularly in the root diameters of 3–5 and 5–10 mm. These two species were both found to be deep-rooted. The triaxial compression tests showed that root cohesion was greater in the VR samples than in the HR samples. SWC was negatively related to both soil shear strength and root cohesion. These results could provide useful information on the architectural characteristics of woody root system and expand the knowledge on shallow slope stabilization and soil erosion control by plant roots on the Loess Plateau.

关键词： root distribution root cohesion root extinction coefficient soil erosion soil reinforcement Loess Plateau

Effect of forest on sediment yield in North China

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International soil and water conservation Research 2013年第1期1卷 58-64页

作者： Yu Xinxiao Wang Henian Xin Zhongbao Lv Xizhi College of soil and water conservation Beijing Forestry UniversityBeijing 100083China key laboratory of soil and water conservation&desertification combating of Ministry of Education Beijing 100083China

Forest-sediment relationship is a hot and important issue in Ecohydrology *** has implemented many large-scale reforestation programmes in the last decades to address the growing soil erosion and *** this study,we made statistical and graphic analyses on the long-term hydrological data of the 39 watersheds in the rocky mountain area of the North China,and then we were able to analyze the effect of forest on sediment *** results show that the effect is weak in the lees-precipitation regions(when MAP500 mm),the impact of forest on reducing sediment yield is different with the varied forest coverage(f),the relationship between the sediment yield and forest coverage show a quadratic polynomial.

关键词： North China Forest Sediment yield Effect

Effect of precipitation condition on photosynthesis and biomass accumulation and referring to splash erosion status in five typical evergreen tree species in humid monsoon climatic region of subtropical hill-land

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Journal of Central South University 2015年第10期22卷 3795-3805页

作者：余蔚青王云琦王玉杰张会兰王彬刘勇 School of soil and water conservation Beijing Forestry University key laboratory of soil and water conservation and desertification Control of Ministry of Education (Beijing Forestry University)

Negative effect of precipitation on plant photosynthesis was investigated in this work. Stomatal conductance, transpiration rate and net photosynthetic rate were measured before and after each precipitation event, respectively, and the corresponding precipitation was recorded as well. Moreover, plant dry matter accumulation was counted at the end of our entire experiment. The results show that precipitation fully demonstrates its negative effect on plant photosynthesis under the condition of without water shortage. Although it has not been proved, leaf shape seems to be associated with this effect. Broad-leaved species are less influenced than coniferous and lanceleaf species no matter on the length of variation time or changes in variation values. The different situation among three broad-leaved species seems to illustrate that the effect is also related to the size of single leaf area. The correlation between precipitation and photosynthetic rate variation is analogous to the relationship between precipitation and splash erosion, and in the view of the relationship between plant photosynthetic characteristics and dry mass accumulation, it can be thought that it can reflect the negative impact of precipitation on plant growth by making use of splash erosion. Therefore, a section was added in the traditional plant biomass estimation algorithms by using eco-physiological models, and this was proved to enhance the accuracy of traditional estimation from preliminary verifications.

关键词： precipitation leaf photosynthesis splash erosion dry matter net primary productivity

Simulated multi-scale watershed runoff and sediment production based on GeoWEPP model

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International Journal of Sediment Research 2009年第4期24卷 465-478页

作者： YU Xinxiao 1 , ZHANG Xiaoming 2 and NIU Lili 31 Prof. Dr., key laboratory of soil and water conservation and desertification combating, Ministry of Education, School of soil and water conservation, Beijing Forestry University, Beijing 100083, China, 2 Dr. China Institute of water Resource and Hydropower Research, Beijing 100048, China 3 Dr., key laboratory of soil and water conservation and desertification combating, Ministry of Education, School of soil and water conservation, Beijing Forestry University, Beijing 100083, China Prof. Dr. Key Laboratory of Soil and Water Conservation and Desertification Combating Ministry of Education School of Soil and Water Conservation Beijing Forestry University Beijing 100083 China Dr. China Institute of water Resource and Hydropower Research Beijing 100048 China Dr. Key Laboratory of Soil and Water Conservation and Desertification Combating Ministry of Education School of Soil and Water Conservation Beijing Forestry University Beijing 100083 China

The runoff and sediment yield data from the Qiaozidonggou, Qiaozixigou, and Lu’ergou watersheds, in the Loess Plateau of China are used to calibrate and validate the runoff and sediment yield simulated by GeoWEPP model of the WEPP Model at watershed scale. The indices of relative error, R, correlation coefficient, R 2 , and Nash-Suttcliffe efficiency coefficient En s are used to evaluate the model fit. The eco-hydrological responses in the Luoyugou and Lu’ergou watersheds are also forecast based on the WEPP Model. Meanwhile, the relation between vegetation pattern changes and sediment yield in the watershed is discussed, and the responses of runoff and sediment yield in the watersheds concerning forest growth stages are studied. The results show that the relative errors of simulated values of runoff and sediment yield are below 30%, the correlation coefficients are above 0.90, and the Nash-Suttcliffe efficiency coefficients are above 0.80. The simulation results present satisfactory performance, thus, the model could be used to simulate the runoff and sediment yield in these small watersheds. It is also observed that soil erosion tended to become severe as precipitation increased in the watershed, while soil erosion has a decreasing trend as forest cover increases and vegetation pattern is optimized. When the watershed is fully covered by forest, erosion and sediment yield are minimized. When the forest cover is about 30% and evenly distributed in the watershed, the erosion intensity is lower than if the forest cover is collectively distributed in the watershed. Erosion varies with different forest growth stages in the watershed; it is more serious at the young and near planting stage and is the smallest at the mature forest stage.

关键词： GeoWEPP model Eco-hydrological response watershed runoff Sediment yield Model calibration Erosion modeling

Effects of extreme soil water stress on photosynthetic efficiency and water consumption characteristics of Tamarix chinensis in China's Yellow River Delta

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Journal of Forestry Research 2017年第3期28卷 491-501页

作者： Yuan Gao Jiangbao Xia Yinping Chen Yanyun Zhao Qingxian Kong Ying Lang soil and water conservation and desertification Control key laboratory of the Ministry of Education Institute of Soil and Water ConservationBeijing Forestry University Shandong Provincial key laboratory of Eco-Environmental Science for Yellow River Delta Binzhou University Shandong Provincial key laboratory of water and soil conservation and Environmental Protection Linyi University

soil moisture is a major limiting factor for plant growth on shell ridge islands in the Yellow River Delta. However, it is difficult to carry out situ experiment to study dominant plant photosynthesis physiological on the shell ridge islands under extreme soil water stress. To evaluate the adaptability of plants to light and moisture variations under extreme soil moisture conditions present on these islands, we measured photosynthetic gas exchange process, chlorophyll fluorescence, and stem sap flow variables for 3-year-old trees of Tamarix chinensis Lour, a restoration species on these islands, subjected to three types of soil water levels： waterlogging stress （WS）, alternating dry-wet （WD）, and severe drought stress （SS） to inform decisions on its planting and management on shell ridge islands. Gas exchange, chlorophyll fluorescence, and stem sap flow in T. chinensis were then measured. Net photosynthetic rate （PN）, transpiration rate （E）, and water use efficiency （WUE） were similar under WS and alternating dry-wet conditions, but their mean E and WUE differed significantly （P 〈 0.05）. Under SS, the PN, E and WErE of T. chinensis leaves varied slightly, and mean PN, E and WUE were all low. Apparent quantum efficiency （AQY）, light compensation point （LCP）, light saturation point （LSP）, and maximum net photosynthetic rate （PNmax） of leaves were not significantly different （P 〉 0.05） under WS and dry-wet conditions; however, under extreme drought stress, compared with the dry-wet conditions, LCP was higher, Lsp was lower, and AQy and PNmax were both at the lowest level. Therefore, drought stress weakened light adaptability of leaves, and the efficiency of light transformation was poorer. （3） Maximum photochemical efficiency （Fv/Fm） and the actual photochemical efficiency （ΦPSII） were similar under waterlogged stress and dry-wet conditions, indicating a similar healthy photosynthetic apparatus and photosynthetic reaction cen- ter activity, respectively. Under SS, Fv/F

关键词： Chlorophyll fluorescence Gas exchange parameters Light use efficiency Stem sap flow wateruse efficiency