条子泥围垦区水盐特征与植被分布的关系          下载免费PDF全文

詹泸成  马芬艳  陈建生  辛沛 《水科学进展》2021,32(1):127-138

为了探究江苏东台条子泥围垦区的水盐分布规律,揭示圆环状植被分布与土壤水盐条件的关系,于2019年9月对围垦区内用作湿地恢复的区域进行测量和采样。在植被环附近测量了二维、三维大地电阻率,采集降水、地表水、土壤、地下水等样品,测试样品的水盐指标和D、18O同位素组成。结果表明:植被圆环下方3 m深度内均存在对应的高电阻率/低盐度区域,且随着植被类型由中心向外环变化,对应的土壤水盐度也逐渐增大;土壤水盐度是不同植被呈现圆环状分布的重要影响因素,其变化受降水入渗和土壤蒸发引起的盐分集结共同作用;土壤盐度直接影响了不同植被种群的分布格局,而植被对入渗和蒸发过程的影响也反作用于土壤盐度分布。  相似文献   

基于Modflow某电厂厂址区地下水环境影响评价研究     

钞中东 《地下水》2019,(1):17-20

根据某火电厂建设项目自身性质及其对地下水环境影响的特点,采用数值模拟法进行预测与评价,建立能够正确刻画评价区地下水流动特征的地下水数值模型,并预测评价项目厂区在建设阶段、运行阶段及服务期满后等3个情景下地下水环境的影响和危害情况。认为本项目废水设计为零排放,不会对场址所在的地下水系统造成新的影响。在正常工况下,建设项目不会对当地地下水产生明显影响。在考虑发生风险事故且防渗措施失效情况下,建设项目对场区及下游地下水环境造成轻微影响,不会引起地下水质量标准降低,在及时采取防渗堵漏措施后,对场区及下游地区地下水不会产生影响。旨在为有效预防和控制电厂区域的地下水环境恶化,保护地下水资源,为电厂工程设计和环境管理提供科学依据。  相似文献   

准噶尔西北部塔尔巴哈台组早石炭世植物和遗迹化石的发现及其古地理意义*   总被引：1，自引：0，他引：1       下载免费PDF全文

纵瑞文  范若颖  赵龙  龚一鸣  王国灿 《古地理学报》2014,16(3):319-334

首次在准噶尔西北部塔尔巴哈台组上部发现了早石炭世维宪期植物化石 Archaeocalamites scrobiculatus,Sublepidodendron grabaui,S. mirabile,S. cf. mirabile,Sublepidodendron sp., Lepidodendropsis sp., Mesocalamites sp., Sigillaria sp., Rhodiopteridium?sp.,Knorria sp.,证实了该组的时代可延续到早石炭世。根据研究区塔尔巴哈台组和上覆黑山头组的生物组合面貌及二者的接触关系,论证了塔尔巴哈台组顶部和黑山头组在准噶尔西北部具有明显的穿时性,前者从杜内期延续到维宪期,后者从杜内期延续到谢尔普霍夫期。与植物化石共同保存的深水相遗迹化石指示了塔尔巴哈台地区在早石炭世早中期为半深海-深海沉积环境,不同于东部吉木乃地区同期的滨浅海沉积环境,说明准噶尔西北部在早石炭世存在着不同的沉积体系。北疆地区早石炭世广泛的海侵活动以及额尔齐斯-斋桑洋向南侧哈萨克斯坦板块俯冲是造成这种沉积差异的主控因素,同时也造成了塔尔巴哈台组和黑山头组在区域上具穿时性。  相似文献   

阿拉善荒漠典型植物功能群氮、磷化学计量特征   总被引：2，自引：0，他引：2  

张珂  陈永乐  高艳红  回嵘  何明珠 《中国沙漠》2014,34(5):1261-1267

氮（N）、磷（P）作为荒漠生态系统重要的养分元素和限制性因子,在维持植物功能群组成及结构稳定、生态系统内养分循环中发挥着重要的作用。本研究沿水热梯度从东至西在阿拉善荒漠设置52个调查样地,通过对优势植物的调查取样,分析了荒漠植物不同功能（类）群N、P元素的生态化学计量特征,并就N、P含量及N：P值对荒漠植物的限制性作用进行了检验和讨论。结果显示：（1）所调查阿拉善荒漠区植物叶片的N、P含量分别为10.65±7.91 mg·g^-1和1.04±0.81 mg·g^-1,N：P值为11.53±5.06,叶片N含量与P含量及N：P值均显著正相关,P含量与N：P值显著负相关;通过对比分析认为该区植物同时受到N、P双重制约,且更易受N限制。（2）从植物生活型比较,认为草本植物叶片N、P含量均高于灌木植物叶片,而灌木植物叶片的N：P值大于草本植物;对光合作用途径分析发现,C₃植物叶片N含量高于C₄植物叶片,而C₄植物叶片P含量高于C₃植物叶片;从系统发育类型方面分析,认为单子叶植物叶片N含量低于双子叶植物叶片N含量,而P含量则高于双子叶植物叶片P含量。  相似文献   

植被功能型、气候和土壤氮素对中国东部南北样带叶片氮浓度空间格局的影响     

展小云  于贵瑞  何念鹏 《资源与生态学报(英文版)》2013,4(2):125-131

我们通过采集中国东部南北样带（NSTEC）上112个样点的102种植物叶片样品,分析了植物叶片氮浓度对植被功能型（PFTs）以及环境因素的响应特征。研究结果表明：（1）植物叶片氮浓度均值为17．7mg.g^-1,最大值和最小值分别出现在落叶阔叶植物和常绿针叶植物中。对乔木而言,叶片氮浓度表现为落叶植物〉常绿植物,阔叶植物〉针叶植物;乔木和灌木的叶片氮浓度显著高于草本植物,而乔木和灌木之间则无显著差异。（2）叶片氮浓度与年均温度（MAT）呈现凸型二次曲线关系,与年均降水量（MAP）则呈现显著的线性负相关关系,与土壤氮素浓度（Nsoil）则线性正相关,并且这种关系并不随着植被功能型的改变而改变。（3）PFTs,气候和Nsoil共同解释植物叶片氮浓度空间格局变异的46．1％,其中PFTs,气候和Nsoil可分别独立解释植物叶片氮浓度空间格局变异的15．6％,2．3％,4．7％。该研究结果表明,气候和土壤氮素对植物叶片氮浓度的影响主要是通过作用于生态系统中的物种组成,而非直接作用实现的。这种基于较大区域尺度上的野外观测分析有助于我们准确的理解植被功能型和环境因素对叶片氮浓度变异的影响机制。  相似文献   

Distribution of petroleum hydrocarbons in soils and the underlying unsaturated subsurface at an abandoned petrochemical site,North China   总被引：1，自引：0，他引：1       下载免费PDF全文

Qian Zhang  Guangcai Wang  Norio Sugiura  Motoo Utsumi  Zhenya Zhang  Yingnan Yang 《水文研究》2014,28(4):2185-2191

Contamination characteristics of petroleum hydrocarbons in soils and the underlying unsaturated subsurface were analysed by investigating and sampling at different depth of five boreholes named SH1 through SH5 at a typical petrochemical site, North China. Topsoil volatile organic gas measurement revealed that SH‐3 was the center of one pollution plume. Soil samples analysis showed that aromatic hydrocarbons and chlorinated hydrocarbons were major pollutants. Their maximum concentration was found at 6.5 and 14.6 m of SH‐2, 13 m of SH‐5, and 18.5 m of SH‐3. These pollutants are mostly accumulated on the interface between two different lithological layers, especially between the sand and silt clay layers. Denitrifying and iron reducing were main biogeochemical processes in this site. Under the influence of groundwater level fluctuation, free NAPLs passed through the boundary and dissolved into the lower groundwater. Knowledge of these associations between contaminant distributions and affecting factors could have implications for soil and groundwater pollution prevention and control. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

2008年以来雅安市地震宏观现象研究     

戈培峰  宁冬梅  韩世康 《四川地震》2014,(1):24-28

强烈地震发生之前出现的宏观异常现象是否与地震相关是一个重要的研究题目。根据雅安市2008~2013年收集到的宏观现象调查资料进行归纳和分析,统计结果显示:雅安市的宏观现象出现后在一定范围发生M≥4级以上地震的对应比率仅占3%,这说明宏观现象与地震发生之间的关系和收集宏观现象的方式需进一步探索。  相似文献   

Mineral weathering and element cycling in soil-microorganism-plant system   总被引：1，自引：0，他引：1  

ZHU YongGuan  DUAN GuiLan  CHEN BaoDong  PENG XinHua  CHEN Zheng  SUN GuoXin 《中国科学:地球科学(英文版)》2014,57(5):888-896

Soil is an essential part of the critical zone,and soil-microbe-plant system serves as a key link among lithosphere,biosphere,atmosphere and hydrosphere.As one of the habitats with the richest biodiversity,soil plays a critical role in element biogeochemistry on the earth surface(weathered crust).Here we review the soil biological processes that are relevant to mineral weathering,element cycling,and transformation,with an emphasis on rock weathering mediated by soil microbes,plant root and the rhizosphere.  相似文献   

Plant root traits affecting the resistance of soils to concentrated flow erosion   总被引：5，自引：0，他引：5  

Melanie Burylo  Freddy Rey  Nicolle Mathys  Thierry Dutoit 《地球表面变化过程与地形》2012,37(14):1463-1470

The effect of plant species on erosion processes may be decisive for long‐term soil protection in degraded ecosystems. The identification of functional effect traits that predict species ability for erosion control would be of great interest for ecological restoration purposes. Flume experiments were carried out to investigate the effect of the root systems of three species having contrasted ecological requirements from eroded marly lands of the French Southern Alps [i.e. Robinia pseudo acacia (tree), Pinus nigra austriaca (tree) and Achnatherum calamagrostis (grass)], on concentrated flow erosion rates. Ten functional traits, describing plant morphological and biomechanical features, were measured on each tested sample. Analyses were performed to identify traits that determine plant root effects on erosion control. Erosion rates were lowest for samples of Robinia pseudo acacia, intermediate in Achnatherum calamagrostis and highest in Pinus nigra austriaca. The three species also differed strongly in their traits. Principal components analysis showed that the erosion‐reducing potential of plant species was negatively correlated to root diameter and positively correlated to the percentage of fine roots. The results highlighted the role of small flexible roots in root reinforcement processes, and suggested the importance of high root surface and higher tensile strength for soil stabilization. By combining flume experiment to plant functional traits measurements, we identified root system features influencing plant species performance for soil protection against concentrated flow erosion. Plant functional traits related to species efficiency for erosion control represent useful tools to improve the diagnosis of land vulnerability to erosion, plant community resistance and the prediction of ecosystem functioning after ecological restoration. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Earth Surface Exchanges (ESEX) Commentary on ‘Plants as river system engineers’ by A. Gurnell. Earth Surface Processes and Landforms 39: 4–25, 2014. DOI 10.1002/esp.3397          下载免费PDF全文

Philip Greenwood  Nikolaus J. Kuhn 《地球表面变化过程与地形》2015,40(1):131-134

In a review of the role of plants in river systems, Gurnell (2014) explains how living riparian vegetation can moderate and manipulate river environments by trapping sediment and promoting longer‐term stability. Although the review concentrates on perennial plants in the humid temperate zone, this commentary acts as a reminder that some plants in other kinds of fluvial environment do not act in this way. This is done by describing how Impatiens glandulifera (Himalayan Balsam), a highly invasive annual plant that is now found in many countries on three separate continents, may significantly increase soil erosion along riverbanks and the riparian zone of inland watercourses. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献