检索结果-南通市图书馆

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan(Siberia)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Forestry Research 2024年第3期35卷 13-27页

作者： Elena A.Babushkina Dmitry R.Dergunov Mikhail S.Zharkov Liliana V.Belokopytova Dina F.Zhirnova Bao Yang Jingjing Liu Xiaomei Peng ·Eugene A.Vaganoy Khakass Technical Institute Siberian Federal UniversityAbakan 655017Russia Institute of Ecology and Geography Siberian Federal UniversityKrasnoyarsk 660036Russia Mathematical Methods and IT department Siberian Federal UniversityKrasnoyarsk 660036Russia Key Laboratory of Desert and desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000People's Republic of China School of Geographic and Oceanographic Sciences Nanjing UniversityNanjing 210093People's Republic of China department of Dendroecology V.N.Sukachev Institute of ForestSiberian Branch of the Russian Academy of ScienceKrasnoyarsk 660036Russia

Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings.This study considered long-term chronologies of tracheid measurements,indexed by a novel approach to separate their specific climatic responses from signal recorded in cell production(closely reflected in tree-ring width).To fll gaps in understanding the impact of climate on conifer xylem structure,Scots pine(Pinus sylvestris L.)trees>200 years old were selected within the forest-steppe zone in southern Siberia.Such habitats undergo mild moisture deficits and the resulting climatic regulation of growth processes.Mean and maximum values of cell radial diameter and cell wall thickness were recorded for each tree ring.Despite a low level of climatogenic stress,components of cell chronologies independent of cambial activity were separated to obtain significant climatic signals revealing the timing of the specific stages of tracheid differentiation.Cell expansion lasted from mid-April to July and was impacted similarly to tree-ring width(stimulated by precipitation and stressed by heat),maximum cell size formed late June.A switch in the climatic responses of mean anatomical traits indicated transition to latewood in mid-July.Secondary wall deposition lasted until mid-September,suppressed by end of season temperatures.Generally,anatomical climatic responses were modulated by a less dry May and September compared with summer months.

关键词： Quantitative wood anatomy Cell radial size Cell wall thickness Pinus sylvestris Climatic response

Bibliometric analysis of the status and trend of biological soil crusts research from 1912 to 2023

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2024年第2期16卷 98-108页

作者： XiaoJu Yang FaSi Wu Long Li QingLin Guo ZongRen Yu SongCong Chen XueYong Zhao Naiman desertification Research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences University of Chinese Academy of Sciences National Research Center for Conservation of Ancient Wall Paintings and Earthen Sites Dunhuang Academy Gansu Provincial Research Center for Conservation of Dunhuang Cultural Heritage Cultural Heritage Conservation and Design Consulting Co. Ltd. of Mogao Grottoes

Biological soil crusts(BSCs) play an important role in soil development and ecological function, and it is more important for quantitatively analyzing the processes and trends of BSCs to identify the advantages and disadvantages of BSCs research for the development and application of BSCs theory. Bibliometric analysis of 2,186BSCs literatures from Web of Science showed an exponential growth trend, as China and the United States as the top 2 in terms of publication volume. High quality publications are mainly from European and American countries, such as the United States, Germany and Spain. The top 3 publishers are Journal of Arid Environments, Soil Biology & Biochemistry and Plant and Soil, and disciplines include ecology, environmental science, and soil science, etc.. Research institutions mainly affiliate to the Chinese Academy of Sciences, United States department of the Interior, United States Geological Survey, Hebrew University of Jerusalem, Consejo Superior de Investigaciones Cientificas, and Universidad Rey Juan Carlos. Authors mainly come from United States, Israel, Spain and China. Funds are mainly from the National Natural Science Foundation of China, Spanish Government,Chinese Academy of Sciences, and National Science Foundation of the United States. Biological soil crusts(biocrusts, cyanobacteria, lichens, moss crusts, bryophytes), drylands, climate change, photosynthesis and desert are high-frequency keywords. Future research will focus on the driving mechanisms of BSCs on global biogeochemical cycles, maintaining global biodiversity on important ecological processes, global C, N, and P cycles. The impact on biological invasion, sandstorms, and water balance, multifunctional and reciprocal mechanisms for maintaining the stability of desert and sandy ecosystems, and impact on the formulation of management policies for arid ecosystems, corresponding to global climate change, and the estimation of regional, local, and microscale distribution of BSCs based on machine deep learning modeling gradually fo

关键词： Biological soil crusts Bibliometric analysis Web of science CiteSpace VOSviewer

Combined effect of micro silica with clay, and gypsum as mulches on shear strength and wind erosion rate of sands

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Soil and Water Conservation Research 2019年第4期7卷 388-394页

作者： Fateme Naghizade Asl Hamid Reza Asgari Hojat Emami Mohammad Jafari department of combating desertification Gorgan University of Agricultural Sciences and Natural Resources***GorganIran department of Soil Science Ferdowsi University of Mashhad***MashhadIran department of combating desertification Tehran University***TehranIran

Mulching is known as one of the fastest strategies to control wind erosion and sand dunes movement.We hypothesized that mixed micro silica with clay,gypsum and clay-gypsum as mulches will increase shear strength,threshold friction velocity and decrease soil losses of drifting sands.For this purpose,mixture of micro silica rates (0,1,5,10,15 and 20%) with clay,gypsum,and clay-gypsum applied on sand surfaces.After 60 days of mulching,shear strength,the threshold friction velocity and soil losses at a wind speed of 15 m/S at the height of 20 cm for 20 rain.The results of this research revealed that the addition of 10% of micro silica in combination with clay and clay-gypsum increased the shear strength up to 10.6 and 37.5% and the threshold friction velocity up to 45.2 and 48.5%,respectively and decreased soil losses up to 100% in comparison with the samples without micro silica.Adding micro silica to gypsum had no considerable effect on shear strength,threshold friction velocity and soil losses.It was concluded that no pozzolanic reaction occurred between micro silica and gypsum and it was found that improvement in mechanical property and erodibility of clay-gypsum mulch was probably due to the pozzolanic reaction between micro silica and clay.Application of 10% of micro silica in combination with clay or clay-gypsum is therefore recommended as suitable mulch.

关键词： Drifting sands Soil loss Threshold friction velocity Micro silica Mulch

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Effects of thinning on stand structure and tree stability in an afforested oriental beech(Fagus orientalis Lipsky) stand in northeast Turkey

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2015年第1期26卷 123-129页

作者： Zafer Yücesan Sevilay ?z?elik Ercan Oktan Faculty of Forestry Karadeniz Technical University General Directorate of combating to desertification and Erosion Control

We studied relationships between stand structure and stand stability according to thinning intensity in an afforested oriental beech stand. Various thinning intensities were applied in sample stands. We sampled eight plots in stands that were lightly thinned, eight plots in heavily thinned stands and eight plots in unthinned stands as a control. Height and diameter distributions of the stands were measured to assess stand structure. We quantified individual tree stability and collective stability. Heavy thinning during the first thinning operation damaged the storied structure of the stand in thicket stage and affected collective structuring ability. While most control plots had multi-storied stands, after light and heavy thinning two-storied structure became more common.Large gaps occurred in the canopy after heavy thinning. On average, nine tree collectives were formed per sampling plot in the untreated stand, seven collectives after thinning in 2008 and four collectives after thinning in 2009. Stable trees accounted for 17 % of trees in control plots, 24 % in lightly thinned plots, and 15 % in heavily thinned plots. Collective stability values were 83 % in control plots, 82 % in lightly thinned plots and 36 % in heavily thinned plots. We conclude that it is necessary to retain collective structuring capacity during thinning operations for sustaining stand stability.

关键词： Oriental beech Thinning Stand structure Tree stability

Quantitative comparison of semi- and fully-distributed hydrologic models in simulating flood hydrographs on a mountain watershed in southwest China

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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,China.Comparisons were made for RLD and RB between soil preferential pathways and soil matrices.RLD and RB declined with the increasing soil depth（0–10,10–20,20–30,30–40,40–50,50–60 cm） in all experimental plots.RLD 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,respectively.Fine root systems had the most pivotal influence on soil preferential flow in this forest ecosystem.In all experimental plots,RB content was the sum of RB from soil preferential pathways and the soil matrix in each soil depth.With 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

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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