检索结果-南通市图书馆

Effects of soil drought on photosynthetic traits and antioxidant enzyme activities in Hippophae rhamnoides seedlings

引用

Journal of Forestry Research 2017年第2期28卷 255-263页

作者： Jingwen Liu Ronghua Zhang Guangcan Zhang Jing Guo Zhi Dong key laboratory of soil erosion and ecological restoration Shandong Agricultural UniversityTai'an 271018Shandong People's Republic of China

Water deficit is one of the major limiting factors in vegetation recovery and reconstruction in the semi-arid area of loess hilly regions. Leaf photosynthesis in Hippophae rhamnoides Linn., a common tree grown in this region, decreases under water stress, but the mechanism responsible is not clear. The objective of this study was to investigate the effects of drought stress on photosynthesis and the relationship between photosynthetic variables and soil water contents to help us better understand the photophysiological characteristics of H. rhamnoides under water stress and guide cultivation in the loess hilly region. Here,gas exchange, chlorophyll fluorescence and antioxidant enzyme activity in leaves of 3-year-old saplings of *** grown in pots were tested under eight soil water conditions. When soil water content（RWC） was between 38.9 and 70.5 %, stomatal limitation was responsible for the reduced net photosynthetic rate（PN）.When RWC was lower than 38.9 %, nonstomatal limitation was the main factor restricting PN. Moderate water stress improved the water use efficiency（WUE） of the *** stress significantly influenced fluorescence variables and the antioxidant enzyme system. When RWC was between 38.9 and 70.5 %, nonphotochemical quenching（NPQ） increased and then decreased, indicating that thermal energy dissipation was a significant photoprotection mechanism. Antioxidant enzymes were activated when RWC ranged from 48.3 to 70.5 %; under severe water stress（RWC ／ 38.9 %）, the antioxidant enzyme system was damaged, the activity of the antioxidant enzymes declined, and membranes were damaged. In the semiarid loess hilly region, RWC between 58.6 and 70.5 % was the economic water threshold value that maintained higher WUE and PN, and the maximum soil water deficit level that could sustain H. rhamnoides was RWC of 38.9 %.

关键词： photosynthetic photosynthesis drought stomatal antioxidant hilly deficit loess cultivation chlorophyll

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

Cloning and expression analysis of the FvNCED3 gene and its promoter from ash(Fraxinus velutina)

引用

Journal of Forestry Research 2019年第2期30卷 471-482页

作者： Tian Li Jingkuan Sun Chuanrong Li Zhaohua Lu Jiangbao Xia Shandong Provincial key laboratory of Eco-Environmental Science for Yellow River Delta Binzhou University Taishan Forest Ecosystem Research Station/Shandong Provincial key laboratory of soil erosion and ecological restoration

The 9-cis-epoxycarotenoid dioxygenase(NCED)gene is rate-limiting in abscisic acid(ABA) *** this study, an NCED gene, designated FvNCED3(KY008746), was cloned from velvet ash(Fraxinus velutina Torr.) with a RACE method. The full length c DNA of FvNCED3 encodes a 573-amino acid *** analysis showed that the FvNCED3 protein was highly homologous to other NCED proteins. The expression patterns of FvNCED3 in different ash organs were analyzed by real-time PCR which revealed that FvNCED3 expression levels were highest in leaves and lowest in roots. The gene expression patterns of FvNCED3 under abiotic stress indicated that its expression increased under drought, salt and ABA stress and decreased due to high and low temperatures. There were no obvious changes under ultraviolet light. The 1094-bp upstream sequence 5' flank regulation region of the FvNCED3 gene was also cloned from ash using the Genome Walking method. To assess the activity of the FvNCED3 promoter, a p FvNCED3 p::GUS plant expression vector was constructed for tobacco transformation. GUS expression of the FvNCED3 GUS enzyme activity was detected in almost all transgenic tobacco tissues, especially in the young leaves,stigma, anther, ovule and ovary. After treating the transgenic tobacco with NaCl and placing it under drought stress, GUS staining of tobacco leaves increased compared with that under normal growth conditions. This result indicates that gene expression driven by the FvNCED3 promoter can be induced by salt and drought stress.

关键词： Ash Function analysis NCED gene Promoter Tobacco

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

Fractal features and infiltration characteristics of the soil from different land uses in a small watershed in a rocky,mountainous area in Shandong Province

引用

Journal of Forestry Research 2020年第3期31卷 1017-1024页

作者： Lei Wang Rui Yang Shuyong Zhang Guangcan Zhang Xia Liu key laboratory of soil erosion and ecological restoration Shandong Agricultural UniversityTaian 271018ShandongPeople’s Republic of China Jiangsu key laboratory of soil and Water Conservation and ecological restoration Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu ProvinceForestry College of Nanjing Forestry UniversityNanjing 210037People’s Republic of China

We studied infiltration and fractal mechanisms on sloping farmlands in a small watershed in Shandong Province in the rocky mountain areas of northern *** studied soil fraction and soil water retention curves,and developed a soil infiltration model to analyze its quantitative relationship with soil particle size and pore dimensions under four types of land use,including sloping farmland,abandoned land,natural forest,and forest plantation(Malus pumila,Crataegus pinnatifida).soil stability infiltration rate ranked as sloping farmland>abandoned land>natural forest>forest *** sequence of soil particle size and pore dimension ranked as natural forest>forest plantation>abandoned land>sloping *** were significant positive correlations between soil particle size and pore dimension,and both were positively correlated with the percent volume of silt and *** were negatively correlated with soil infiltration *** Horton model and the power function model were more suitable for simulating soil infiltration and the infiltration *** concluded that the soil in this area displayed typical fragments of rocky mountainous regions due to the loss of silt and clay caused by cultivation on sloping *** uniformity and fractal dimensions of soil particle sizes and pore distribution decreased,thereby enhancing soil infiltration capacity and decreasing soil water retention capacity.

关键词： soil structure soil infiltration Fractal dimension Sloping farmland Rocky mountainous area

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

Drivers of soil erosion and subsurface loss by soil leakage during karst rocky desertification in SW China

引用

International soil and Water Conservation Research 2022年第2期10卷 217-227页

作者： Xudong Peng Quanhou Dai College of Forestry Guizhou UniversityGuiyang550025China Institute of soil erosion and ecological restoration Guizhou UniversityGuiyang550025China The key laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region(Ministry of Education) Collaborative Innovation Center for Mountain Ecology&Agro-Bioengineering(CICMEAB)Research Center of Soil Erosion and Ecological RestorationGuizhou UniversityGuiyang550025China

As an extreme manifestation of environmental degradation,karst rock desertification is caused by soil loss and rock *** some areas with serious rocky desertification,there is no soil to be eroded or *** soil loss in these areas superimposes soil erosion and unique subsurface loss by soil leakage through fissures,pipelines,sinkholes,etc.,which directly reduce soil resources and accelerate rocky ***,the factors driving soil erosion and subsurface loss by soil leakage are still *** experiments were conducted on simulated slopes with surface-exposed bedrock and subsurface fissures based on field investigations in a karst rocky desertification area of Guizhou Province,*** factors,including rainfall intensity,slope gradient,bedrock exposure rate and subsurface fissure degree,were considered in the *** found that the amount of soil surface erosion and subsurface leakage loss is driven not only by the runoff volume but also by other influential *** intensity is the driving factor determining the amount of surface erosion and subsurface leakage loss of soil and water and the relationship between *** slope gradient plays a leading role only in subsurface fissure flow leakage *** bedrock exposure rate drives the surface soil erosion rate,shows a critical value(30%),and dominates the fissure flow leakage loss *** fissure density plays an important role in the surface loss of soil and water;however,an increase in the subsurface fissure density does not obviously accelerate the subsurface leakage loss of soil and *** this result,obtained from laboratory simulations,may differ at the field scale or larger,it could provide a foundation for systematic studies on soil erosion/leakage and insights into the relations between rocky desertification and soil erosion/leakage and their driving factors in karst rocky desertification.

关键词： Driving factors Karst rocky desertification soil erosion Subsurface leakage Southwest China

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

Effects of experimental warming on soil microbial communities in two contrasting subalpine forest ecosystems,eastern Tibetan Plateau,China

引用

Journal of Mountain Science 2016年第8期13卷 1442-1452页

作者： SUN Di-di LI Yue-jiao ZHAO Wen-qiang ZHANG Zi-liang LI Dan-dan ZHAO Chun-zhang LIU Qing key laboratory of Mountain ecological restoration and Bioresource Utilization&ecological restoration and Biodiversity Conservation key laboratory of Sichuan Province Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041China ecological Security and Protection key laboratory of Sichuan Province Mianyang Normal UniversityMianyang 621000China State key laboratory of soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

soil microbial communities are primarily regulated by environmental temperature. Our study investigated the effects of global warming on soil microbial community composition as measured via phospholipid fatty acid （PLFA） analysis and soil chemical characteristics in relation to soil depth in a dragon spruce plantation and a spruce-fir-dominated natural forestin the Eastern Tibetan Plateau. Opentop chambers were utilized to increase the soil and air temperature. soil samples were collected from the o-10 cm, 10-20cm, and 20-30 cm layers after a 4-year warming. Our results showed that the soil microbial community and the contents of TC （Total carbon）, TN （Total nitrogen）. NO3-. and NH4＋ responded differently to warming in the two contrasting forests, especially at the 0-10 cm soil depth. Warming increased soil microbial biomass at the 0-20 cm depth of soil in natural forest but reduced it at the o-lo cm depth ofsoil in the plantation. In contrast, the TC and TN contents were reduced in most soil layers of a natural forest but increased in all of the soil layers of the plantation under warming conditions. This result suggested that the effects of warming on soil microbial community and soil C and N pools would differ according to soil depth and forest types; thus, the two contrasting forests would under go differing changes following the future climate warming in this region.

关键词： Microbial biomass Microbialcommunity Phospholipid fatty acid (PLFA) Eastern

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

soil mulching can mitigate soil water defi ciency impacts on rainfed maize production in semiarid environments

引用

Journal of Integrative Agriculture 2015年第1期14卷 58-66页

作者： ZHU Lin LIU Jian-liang LUO Sha-sha BU Ling-duo CHEN Xin-ping LI Shi-qing State key laboratory of soil erosion and Dryland Farming on the Loess Plateau Northwest A&F University key laboratory of Mountain ecological restoration and Bioresource Utilization Chengdu Institute of BiologyChinese Academy of Sciences Center for Resources Environment and Food SecurityChina Agricultural University

Temporally irregular rainfall distribution and inefficient rainwater management create severe constraints on crop production in rainfed semiarid areas. Gravel and plastic film mulching are effective methods for improving agricultural productivity and water utilization. However, the effects of these mulching practices on soil water supply and plant water use associated with crop yield are not well understood. A 3-yr study was conducted to analyze the occurrence and distribution of dry spells in a semiarid region of Northwest China and to evaluate the effects of non-mulching （CK）, gravel mulching （GM） and plastic film mulching （FM） on the soil water supply, plant water use and maize （Zea mays L.） grain yield. Rainfall analysis showed that dry spells of ≥5 days occurred frequently in each of 3 yr, accounting for 59.9-69.2% of the maize growing periods. The 〉15-d dry spells during the jointing stage would expose maize plants to particularly severe water stress. Compared with the CK treatment, both the GM and FM treatments markedly increased soil water storage during the early growing season. In general, the total evapotranspiration （ET） was not significantly different among the three treatments, but the mulched treatments significantly increased the ratio of pre- to post-silking ET, which was closely associated with yield improvement. As a result, the grain yield significantly increased by 17.1, 70.3 and 16.7% for the GM treatment and by 28.3, 87.6 and 38.2% for the FM treatment in 2010, 2011 and 2012, respectively, compared with the CK treatment. It＇s concluded that both GM and FM are effective strategies for mitigating the impacts of water deficit and improving maize production in semiarid areas. However. FM is more effective than GM.

关键词： semiarid areas plastic film mulching gravel mulching dry spell evapotranspiration maize yield

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

Plant–soil microbe feedbacks drive seedling establishment during secondary forest succession:the‘successional stage hypothesis’

引用

Journal of Plant Ecology 2023年第6期16卷 259-270页

作者： Qing Liu Wenqiang Zhao CAS key laboratory of Mountain ecological restoration and Bioresource Utilization&ecological restoration Biodiversity Conservation key laboratory of Sichuan Province Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041China

INTRODUCTION Forests are increasingly under threat due to logging,fire,severe drought and other natural disturbances,which may compromise their ability to conserve biodiversity and regulate climate systems(Powers and Marin-spiotta 2017).Extensive deforestation and forest degradation will leave behind a complex landscape consisting of a matrix of forest patches under different levels of succession(Quesada et al.2009).

关键词： forest seedling soil

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

The effects of phenolic acid on nitrogen metabolism in Populus 3 euramericana ‘Neva’

引用

Journal of Forestry Research 2018年第4期29卷 923-929页

作者： Hui Li Huicheng Xie Zilong Du Xianshuang Xing Jie Zhao Jing Guo Xia Liu Shuyong Zhang key laboratory of soil erosion and ecological restoration of Shandong Province Forestry College Shandong Agricultural University Taian 271018 China College of Agriculture and Forestry Science Linyi University Linyi 276000 China Hydrographic Office of Shandong Province Jinan 250002China Jiangsu key laboratory of soil and Water Conservation and ecological restoration Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province Forestry College of Nanjing Forestry University Nanjing 210037 China

The declines in soil fertility and productivity in continuously cropped poplar plantations axe related to phenolic acid accumulation in the soil. Nitrogen is a vital life element for poplar and whether the accumulation of phenolic acid could influence nitrogen metabolism in poplar and thereby hinder continuous cropping is not clear. In this study, poplar cuttings of Populus × euramericana ‘Neva＇ were potted in vermiculite, and phenolic acids at three concentrations （032, 0.5X and 1.0X） were added according to the actual content （1.0X） in the soil of a second-generation poplar plantation. Each treatment had eight replicates. We measured gas exchange parameters and the activities of key enzymes related to nitrogen metabolism in the leaves. Leaf photosynthetic parameters varied with the concentration of phenolic acids. The net photosynthetic rate （PN） significantly decreased with increasing phenolic acid concentration, and non-stomatal factors might have been the primary limitation for PN- The activities of nitrate reductase （NR）, glutamine synthetase （GS） and glutamate synthase （GOGAT）, as well as the contents of nitrate nitrogen, ammonium nitrogen, and total nitrogen in the leaves decreased with increasing phenolic acid concentration. This was significantly and positively related to PN （P 〈 0.05）. The low concentration of phe- nolic acids mainly affected the transformation process of NO3- to NO2-, while the high concentration of phenolic acids affected both processes, where NO3- was transferred to NO2- and NH4＋ was transferred to glutamine （Gln）. Overall, phenolic acid had significant inhibitory effects on the photosynthetic productivity of Populus x euramericana ＇Neva＇. This was probably due to its influence on the activities of nitrogen assimilation enzymes, which reduced the amount of amino acids that were translated into protein and enzymes. Improving the absorption and utilization of nitrogen by plants could help to overcome the problems caused by continuous cro

关键词： Continuous cropping management Poplar Phenolic acids Photosynthesis Nitrogen metabolism Enzyme activity

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

Temporal sediment source tracing during storm events in the black soil region, Northeast China

引用

International soil and Water Conservation Research 2024年第2期12卷 322-336页

作者： Lin Su Donghao Huang Lili Zhou Chengjiu Guo Baoyong Liu College of Water Conservancy Shenyang Agricultural UniversityShenyang110866China key laboratory of soil erosion Control and ecological restoration in Liaoning Province Shenyang110866China College of Environmental Science and Engineering Liaoning Technical UniversityFuxin123000China

Sediment fingerprinting technology is widely used to differentiate sediment ***,despite its long-recognized benefits,there it has been seldom applied to assess the variability of sediment sources during storm *** this study,sediment fingerprinting is used for four storm events to determine the dynamic changes in sediment sources throughout them in the black soil region in Northeast *** potential sediment sources—cultivated land,unpaved roads,and gullies—were effectively differentiated using four geochemical tracers(As,Be,Cs,and Cu),with an accuracy of 100%.The relative sediment contribution from each source was determined using linear and Bayesian mixing *** mean absolute fit(MAF)values of the linear mixing model(MAF_(mean)=0.976–0.949)were higher than those of the Bayesian mixing model(MAF_(mean)=0.921–0.992),indicating that the first performed *** land was the primary source of the sediment load,accounting for 59.03%of it(load-weighted mean=68.29%),followed by the gullies(37.15%,load-weighted mean=28.09%),and unpaved roads(3.90%,load-weighted mean=3.69%)for the four storm *** addition,a high variability in sediment source contribution was observed during the storm *** land was the dominant sediment source during storm events with higher sediment concentrations(logarithmic function,r^(2)=0.878,perosion ***,it provides data support for exploring soil erosion mechanisms and effective erosion control in the black soil region in Northeast China.

关键词： Sediment flux Sediment sources Sediment source fingerprinting Storm event Black soil region

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

Spatial-temporal differentiation and influencing factors of rural settlements in mountainous areas: an example of Liangshan Yi Autonomous Prefecture, Southwestern China

引用

Journal of Mountain Science 2024年第1期21卷 218-235页

作者： WANG Yumeng DENG Qingchun YANG Haiqing LIU Hui YANG Feng ZHAO Yakai School of Geographical Sciences China West Normal UniversityNanchong 637009China Sichuan Provincial Engineering laboratory of Monitoring and Control for soil erosion in Dry Valleys China West Normal UniversityNanchong 637009China Liangshan soil erosion and ecological restoration in Dry Valleys Observation and Research Station Xide 616753China

Rural settlement is the basic spatial unit for compact communities in rural area. Scientific exploration of spatial-temporal differentiation and its influencing factors is the premise of spatial layout rationalization. Based on land use data of Liangshan Yi Autonomous Prefecture(hereinafter referred to as Liangshan Prefecture) in Sichuan Province, China from 1980 to 2020, compactness index, fractal dimension, imbalance index, location entropy and the optimal parameters-based geographical detector(OPGD) model are used to analyze the spatial-temporal evolution of the morphological characteristics of rural settlements, and to explore the influence of natural geographical factors, socioeconomic factors, and policy factors on the spatial differentiation of rural settlements. The results show that:(1) From 1980 to 2020, the rural settlements area in Liangshan Prefecture increased by 15.96 km^(2). In space, the rural settlements are generally distributed in a local aggregation, dense in the middle and sparse around the periphery. In 2015, the spatial density and expansion index of rural settlements reached the peak.(2) From 1980 to 2020, the compactness index decreased from 0.7636 to 0.7496, the fractal dimension increased from 1.0283 to 1.0314, and the fragmentation index decreased from 0.1183 to 0.1047. The spatial morphological structure of rural settlements tended to be loose, the shape contour tended to be complex, the degree of fragmentation decreased, and the spatial distribution was significantly imbalanced.(3) The results of OPGD detection in 2015 show that the influence of each factor is slope(0.2371) > traffic accessibility(0.2098) > population(0.1403) > regional GDP(0.1325) > elevation(0.0987) > poverty alleviation(0). The results of OPGD detection in 2020 show that the influence of each factor is slope(0.2339) > traffic accessibility(0.2198) > population(0.1432) > regional GDP(0.1219) > poverty alleviation(0.0992) > elevation(0.093). Natural geographical facto

关键词： Rural settlements Location entropy Geographical detector Spatiotemporal differentiation Influencing factors

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：