检索结果-南通市图书馆

Soil Fertility Indices of Citrus Orchard Land Along Topographic Gradients in the Three Gorges Area of China

Pedosphere 2011年第6期21卷 782-792页

作者： WU Dian-Ming YU Yuan-Chun XIA Li-Zhong YIN Shi-Xue YANG Lin-Zhang college of Forest Resources and Environment Nanjing Forestry University Nanjing 210037 （China） state Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） college of environmental science and Engineering Yangzhou University Yangzhou 22500g （China）

In the Three Gorges Area of China, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. Although efforts have been undertaken to reduce soil and water losses from slope land used for citrus production, information on the effects of management practices on soil fertility indices is either limited or nonexistent. This study was conducted to compare the effects of 10 years of various management practices, citrus intercropped with white clover (WC), citrus mulched with straw (SM), citrus intercropped with contour hedgerows (CH), citrus orchard land with impermeable membrane (IM), and citrus intercropped with wheat (Triticum aestivum) and peanut (Arachris hypogaea) (WP), as treatments on soil fertility indices with that of the conventional citrus management (CM). Results showed that the soil organic carbon, total and available nitrogen, available potassium, and water-stable aggregate (> 0.25 mm) contents at the 0–5 cm depth were higher for the WC and SM treatments than the CM treatment. There was also spatial variation in soil fertility along slopes of the WC and SM treatments. The soil total and available nitrogen, phosphorus, and potassium, and water-stable aggregate (> 0.25 mm) contents at both the 0–5 and 5–20 cm depths were higher for the CH and IM treatments than the CM treatment. The average soil available nitrogen and available potassium contents were higher for the WP treatment than the CM treatment, but the WP treatment had little effect on the soil organic carbon, total nitrogen, and water-stable aggregate (> 0.25 mm) contents. These suggested that white clover intercropping and straw mulching were the most effective approaches to improve soil fertility in citrus orchard land of the Three Gorges area.

关键词： intercropping slope land soil nutrients soil water-stable aggregates straw mulching

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of thinning intensity on the stem CO_(2) efflux of Larix principis-rupprechtii Mayr

引用

Forest Ecosystems 2021年第4期8卷 841-855页

作者： Kuangji Zhao Timothy J.Fahey Xiangzhen Wang Jie Wang Fang He Chuan Fan Zhongkui Jia Xianwei Li Sichuan Province Key Laboratory of Ecological forestry Engineering on the Upper Reaches of the Yangtze River College of ForestrySichuan Agricultural University611130 ChengduChina Key Laboratory for Silviculture and Conservation of the Ministry of Education College of ForestryBeijing Forestry University100083 BeijingChina Department of Natural Resources Cornell University14853 New YorkUSA

Background:Stem CO_(2) efflux(E_(S))plays a critical role in the carbon budget of forest *** is a core practice for sustainable management of *** is therefore necessary and urgent to study the effect and mechanism of thinning intensity(TI)on E_(S).Methods:In this study,five TIs were applied in Larix principis-rupprechtii Mayr 21-,25-,and 41-year-old stands in North China in *** infrared gas analyzer(Li-8100 A)was used to measure ES and its association with environmental factors at monthly intervals from May to October in 2013 to *** addition,nutrients,wood structure and nonstructural carbon(NSC)data were measured in August ***:The results show that ES increased with increasing *** maximum ES values occurred at a TI of 35%(3.29,4.57 and 2.98μmol·m^(-2)·s^(-1))and were 1.54-,1.94-and 2.89-fold greater than the minimum E_(S) value in the CK stands(2.14,2.35 and 1.03μmol·m^(-2)·s^(-1))in July for the 21-,25-and 41-year-old forests,*** E_(S) of the trees in low-density stands was more sensitive to temperature than that of the trees in high-density *** sugars(SS)and temperature are the main factors affecting *** the stand density is low enough as 41-year-old ***-rupprechtii forests with TI 35%,bark thickness(BT)and humidity should be considered in addition to air temperature(T_(a)),wood temperature(T_(w)),sapwood width(SW),nitrogen concentration(N)and SS in the evaluation of *** a change in stand density is ignored,the CO_(2) released from individual 21-,25-and 41-year-old trees could be underestimated by 168.89%,101.94% and 200.49%,***_(2) release was estimated based on the stem equation in combination with the factors influencing ES for ***:We suggest that it is not sufficient to conventional models which quantify ES only by temperature and that incorporating the associated drivers(***,SS,SW and N)based on stand density into conventional model

关键词： Stem CO_(2)efflux Thinning intensity environmental factors Nutrient content Wood structure Nonstructural carbon Larix principis-rupprechtii

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

environmental dispersivity in free-water-surface-effect dominated wetland:multi-scale analysis

引用

Frontiers of environmental science & Engineering 2011年第4期5卷 597-603页

作者： Zi WU Zhi LI Li ZENG Ling SHAO Hansong TANG Qing YANG Guoqian CHEN state Key Laboratory of Turbulence and Complex Systems College of EngineeringPeking UniversityBeijing 100871China Department of Civil Engineering City University of New York City CollegeNew YorkNY 10031USA

Distinct from the case with width-dominated shallow wetland flows,the longitudinal evolution of contaminant concentration in the most-typical pattern of wetland as dominated by free-water-surface-effect is characterized by a multi-scale analysis in the present *** environmental dispersion model for the evolution of the mean concentration is deduced as an extension of Taylor's classical formulation by Mei’s multi-scale *** environmental dispersivity is found identical to that determined by the method of concentration moments.

关键词： free-surface wetland environmental dispersion multi-scale analysis

来源：

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

Assessing stand structure in successional stages of dark coniferous forests in western Sichuan, China

引用

Journal of forestry Research 2016年第4期27卷 779-786页

作者： Jiangming Ma Shirong Liu Zuomin Shi Jingxin Wang Key Laboratory of Forest Ecology and Environment State Forestry Administration Institute of Forest EcologyEnvironment and Protection Chinese Academy of Forestry college of Life science Guangxi Normal University Key Laboratory of Ecology of Rare and Endangered Species and environmental Protection (Guangxi Normal university) Ministry of Education China Division of forestry and Natural Resources West Virginia University

Subalpine dark coniferous forests in the western Sichuan Province of China play an important role in the hydrological processes in the upper reaches of the Yangtze River. Second-growth forests, with different stand successional stages, have developed as a result of logging over the past 50 years. Forest cover and stand structure changed greatly with concomitant degradation of forest ecosystem functions. To understand how the stand structures of the second-growth forests change during the stand succession process, we analyzed stand structure characteristics and an old-growth state index of the bamboo and moss-forest types. We found that stand structure at the young successional stage featured one-third of the structure characteristics of the old-growth dark coniferous forests,while the structure of the medium-aged stage had reached half the structure of the old-growth state. The two forest types were similar in the rate of development at the young successional stage but differed at the medium-aged stage;the moss-forest type had more advanced development than the bamboo-forest type at the medium-aged successional stage.

关键词： stand forests bamboo leaved ecosystem logging young Yangtze succession shrub

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Seedling growth and metal accumulation of selected woody species in copper and lead/zinc mine tailings

引用

Journal of environmental sciences 2011年第2期23卷 266-274页

作者： Xiang Shi Xiaolei Zhang Guangcai Chen Yitai Chen Ling Wang Xiaoquan Shan Research Institute of Subtropical forestry Chinese Academy of Forestry Fuyang 311400 China college of forestry Shandong Agricultural University Taian 271018 China college of Agronomy and Biotechnology Yunnan Agricultural University Kunming 650201 China state Key Laboratory of environmental Chemistry and Ecotoxicology Research Center for Econvironmental Sciences Chinese Academy of Sciences Beijing 100085 China

A greenhouse pot experiment was conducted to evaluate the potential of selected woody plants for revegetation in copper （Cu） and lead/zinc （Pb/Zn） mine tailing areas. Five woody species （Amorpha fruticosa Linn, Vitex trifolia Linn. var. simplicifolia Chum, Glochidion puberum （Linn.） Hutch, Broussonetia papyrifera, and Styrax tonkinensis） and one herbaceous species （ Sesbania cannabina Pets） were planted in Cu and Pb/Zn tailings to assess their growth, root morphology, nutrition uptake, metal accumulation, and translocation in plants. Amorpha fruticosa maintained normal growth, while the other species demonstrated stress related growth and root development. Sesbania cannabina showed the highest biomass among the plants, although it decreased by 30% in Cu tailings and 40% in Pb/Zn railings. Calculated tolerance index （TI） values suggested that A. fruticosa, an N-fixing shrub, was the most tolerant species to both tailings （TI values 0.92-1.01）, while S. cannabina had a moderate TI of 0.65-0.81 and B. papyrifera was the most sensitive species, especially to Pb/Zn tailings （TI values 0.15-0.19）. Despite the high concentrations of heavy metals in the mine tailings and plants roots, only a small transfer of these elements to the aboveground parts of the woody plants was evident from the low translocation factor （TF） values. Among the woody plants, V. trifolia var. simplicifolia had the highest TF values for Zn （1.32）, Cu （0.78）, and Pb/Zn （0.78）. The results suggested that A. fruticosa and S. cannabina, which have the highest tolerance and biomass production, respectively, demonstrated the potential for tailings revegetation in southern China.

关键词： woody plants mine tailing tolerance revegetation root

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Patterns and driving factors of leaf C,N,and P stoichiometry in two forest types with different stand ages in a mid-subtropical zone

引用

Forest Ecosystems 2022年第1期9卷 47-56页

作者： Yunni Chang Quanlin Zhong Hong Yang Chaobin Xu Weiping Hua Baoyin Li Fujian Provincial Key Laboratory for Plant Eco-physiology Fujian Normal UniversityFuzhou350007China college of Geographical sciences Fujian Normal UniversityFuzhou350007China state Key Laboratory for Subtropical Mountain Ecology of the Ministry of science and Technology and Fujian Province Fujian Normal UniversityFuzhou350007China college of environmental science and Engineering Fujian Normal UniversityFuzhou350007China Department of Geography and environmental science University of ReadingReadingUK college of Ecological and Resources Engineering Wuyi UniversityWuyishan354300China college of forestry Fujian Agriculture and Forestry UniversityFuzhou350002China

Background:Carbon(C),nitrogen(N),and phosphorus(P)stoichiometry is a key indicator of nutrient utilization in plants,and C/N/P ratios are related to the life histories and adaptation strategies of tree ***,no consensus has been reached on how leaf stoichiometric characteristics are affected by forest type and stand *** relationships between leaf stoichiometry and geographical,meteorological,and soil factors also remain poorly ***:Leaf and soil were sampled from forest stands of different age groups(young,middle-aged,near-mature,and mature)in two forest types(Chinese fir(Cunninghamia lanceolata)forests and evergreen broadleaved forests).The relationships between leaf C,N,and P stoichiometric parameters and geographical,meteorological,and soil factors were analysed by using redundancy analysis(RDA)and stepwise linear regression ***:Leaf C concentrations peaked in the near-mature stands with increasing age irrespective of forest *** N and P concentrations fluctuated with a rising trend in Chinese fir forests,while decreased first and increased later from young to mature phases in natural evergreen broadleaved *** fir forests were primarily limited by N and P,while natural evergreen broadleaved forests were more susceptible to P *** C,N,and P stoichiometric characteristics in Chinese fir forests were mainly affected by the soil total P concentration(SP),longitude(LNG),growing season precipitation(GSP)and mean temperature in July(JUT).The leaf C concentration was mainly affected by GSP and JUT;leaf N and P concentrations were both positively correlated with LNG;and leaf P was positively correlated with *** evergreen broadleaved forests,however,leaf stoichiometric parameters displayed significant correlations with latitude(LAT)and mean annual precipitation(MAP).Conclusions:Leaf stoichiometry differed among forest stands of different age groups and forest *** C,N,and P stoichiometry was pri

关键词： Leaf stoichiometry C/N/P ratios environmental factors Stand age groups Chinese fir forest Natural evergreen broadleaved forest

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Initial results for urban metal distributions in house dusts of Syracuse,new york,USA

引用

science China(Life sciences) 2005年第Z1期48卷 92-99页

作者： D.L.Johnson J.Hager A.Hunt D.A.Griffith S.Blount S.Ellsworth J.Hintz R.Lucci A.Mittiga D.Prokhorova L.Tidd M.M.Millones M.Vincent SUNY college of environmental science and forestry SyracuseNYUSA Upstate new york Specialist environmental Consulting 15 Elizabeth St.BaldwinsvilleNYUSA Department of Geography Syracuse UniversitySyracuseNYUSA Department of Geography and Regional Studies University of MiamiCoral GablesFLUSA Department of Chemistry LeMoyne CollegeSyracuseNYUSA

A program of house dust sample collection and analysis has begun in Syracuse,new york,USA,in order to determine the feasibility of a geography-based exposure assessment for urban *** sampling program,and the protocols it employs,is described for two different types of wipe media,Ghost Wipes and Whatman *** results show that strong spatial patterns of floor dust loading(mg dust per square foot)can be observed for data aggregated at a spatial scale of about 1600 m(~2.5 km^(2)).Floor dust metal concentrations were similar to those found in other urban environments,with some regional *** median floor dust Pb concentration was~108 mg·kg^(-1)for this initial data set of~264 sampled residential locations,and varied from 50 to 1100 mg Pb·kg^(-1).

关键词： floor dust loading wipe tests GIS dust Pb concentration humidity corrections

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of the Variability of Canopy Resistance over a Desert Steppe Site in Inner Mongolia, China

引用

Advances in Atmospheric sciences 2014年第3期31卷 681-692页

作者： ZHANG Guo ZHOU Guangsheng CHEN Fei WANG Yu Chinese Academy of Meteorological sciences university of Chinese Academy of sciences state Key Laboratory of Vegetation and environmental Change Institute of Botany Chinese Academy of Sciences National Center for Atmospheric Research college of forestry Henan University of Science and Technology

ABSTRACT Canopy resistance substantially affects the partitioning of available energy over vegetated surfaces. This study analyzed the variability of canopy resistance and associated driving environmental factors over a desert steppe site in Inner Mongolia, China, through the use of eddy-flux and meteorological data collected from 2008 to 2010. Distinct seasonal and interannual variabilities in canopy resistance were identified within those three years, and these variabilities were controlled primarily by precipitation. Strong interannual variability was found in vapor pressure deficit （VPD）, similar to that of air temperature. Based on the principal component regression method, the analysis of the relative contribution of five major environmental factors [soil-water content （SWC）, leaf-area index （LAI）, photosynthetically active radiation （Kp）, VPD, and air temperature] to canopy resistance showed that the canopy-resistance variation was most responsive to SWC （with 〉 35% contribution）, followed by LAI, especially for water-stressed soil conditions （〉 20% influence）, and VPD （consistently with an influence of approximately 20%）. Canopy-resistance variations did not respond to Kp due to the small interannual variability in Kp during the three years. These analyses were used to develop a new exponential function of water stress for the widely used Jarvis scheme, which substantially improved the calculation of canopy resistance and latent heat fluxes, especially for moist and wet soils, and effectively reduced the high bias in evaporation estimated by the original Jarvis scheme. This study highlighted the important control of canopy resistance on plant evaporation and growth for the investigated desert steppe site with a relatively low LA1.

关键词： variability canopy resistance desert steppe site principal component regression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nonpolar cross-stacked super-aligned carbon nanotube membrane for efficient wastewater treatment

引用

Frontiers of environmental science & Engineering 2023年第3期17卷 37-47页

作者： Shuang Zhang Shuai Liang Yifan Gao Yang Wu Xia Huang Bejing Key Laboratory for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Engineering Research Center for Water Pollution Source Control&Eco-remediation College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China state Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center Tsinghua UniversityBeijing 100084China

Membrane separation technology has made great progress in various practical applications,but the unsatisfactory separation performance of prevailing membrane materials hampers its further sustainable *** study proposed a novel nonpolar super-aligned carbon nanotube(SACNT)membrane,which was prepared with a layer-by-layer cross-stacking *** controlling the number of stacked SACNT layers,three kinds of SACNT membranes(SACNT_200,SACNT 300,and SACNT_400)were *** characterizations and filtration tests were performed to investigate their physico-chemical properties,surface wetting behavior,and filtration *** with two commercial membranes(Com_0.22 and Com_0.45),all the SACNT membranes achieved smoother and more uniform *** to the hexagonal graphene structure of CNTs,the surface chemistry of the SACNT membranes is simple and inert,thereby potentially eliminating the covalent-bonding-induced membrane ***,the SACNT membranes exhibited a typical nonpolar wetting behavior,with high contact angles for polar liquids(water:~124.9°-126.5°;formamide:~80.0°-83.99)but low contact angles for nonpolar diodomethane(~18.8°-20.99).This unique nonpolar feature potentially leads to weak interactions with polar ***,compared with the commercial membranes,the SACNT membranes obtained a significantly higher selectivity while achieving a comparable or higher permeability(depending on the number of stacked layers).Moreover,the SACNT membranes exhibited superior separation performance in various application scenarios,including municipal wastewater treatment(2.3 times higher cleaning efficiency),electro-assistant fouling inhibition(or even self-cleaning),and oil/water separation(>99.2%of separation efficiency),suggesting promising application prospects in various fields.

关键词： Membranefouling Wastewater Membrane separation Antifouling Aligned carbon nanotube

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new Species of the Genus Elaphe(Squamata: Colubridae) from Zoige County,Sichuan,China

引用

Asian Herpetological Research 2012年第1期3卷 38-45页

作者： Song HUANG Li DING Frank T.BURBRINK Jun YANG Jietang HUANG Chen LING Xin CHEN Yaping ZHANG college of Life and Environment sciences Huangshan University state Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of Sciences Huangshan Institute of Ophiology Chengdu Institute of Biology Chinese Academy of Sciences Department of Biology the College of Staten Islandthe City University of New York Department of Biology the Graduate Centerthe City University of New York School of Life sciences Sichuan University college of forestry Southwest Forestry University

Previous phylogenetic analyses of DNA sequence data reveal a likely new species of Elaphe Fitzinger from China,which forms the sister group of all extant Elaphe. One of the three original specimens is crushed and the other two are neonates,which precludes a morphological analysis. Three adult snakes(2 females,1 male) collected from Jiangzha Hot Spring in Zoige County,Sichuan,China on 26 July 2010 now facilitate the species’ description. Mitochondrial DNA nucleotide sequences of cytochrome b(cyt b),NADH dehydrogenase subunit 4(ND4),12S ribosomal RNA(12S rRNA),and cytochrome oxidase subunit 1(CO1) from the adults are identical to sequences from the crashed specimen. Interspecific uncorrected p-distances of partial CO1 gene of 26 sequences from all 11 species of Elaphe,including this new species,are large(8.5–15.2%). This new species is morphologically distinguished from all other species of Elaphe by several characters: 'M'-shaped marking on the supraoculars and adjacent frontal; four parallel series of red-brown spots on the dorsum extending from the neck to the vent; four longitudinal stripes associated with the spots; each spot is usually composed of a whole(or incomplete) red-brown scale with puce borders; spots of each stripe are similar in shape,they occur at relatively regular intervals of one or two scales,and they are slightly red-brown in color; and it has three preoculars,whereas all other species have one or two. Now Elaphe contains 11 species and this discovery highlights the need for continued exploration of temperate regions.

关键词： new species mitochondrial DNA DNA barcoding Zoige ratsnake

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：