Dynamic Changes of Animal Community Composition and Distribution by Spartina Invasion in Yancheng Beach Wetland,China          下载免费PDF全文

Guilin Xie  Baozhong Wang  Kuijun Zhao  Susu Li  Lihua Zhou 《洁净——土壤、空气、水》2015,43(10):1409-1418

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The Invasion of Spartina alterniflora Alters Carbon Dynamics in China's Yancheng Natural Reserve          下载免费PDF全文

Changfang Zhou  Hui Zhao  Zhiyi Sun  Luxian Zhou  Chao Fang  Yan Xiao  Zifa Deng  Yingbiao Zhi  Yongqiang Zhao  Shuqing An 《洁净——土壤、空气、水》2015,43(2):159-165

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岩溶区土著植物黄荆条和红背山麻杆水浸提液对入侵植物飞机草萌发的影响   总被引：3，自引：1，他引：2  

潘玉梅  唐赛春  蒲高忠  李先琨  陈秋霞  韦春强 《中国岩溶》2008,27(2):097-102

黄荆条和红背山麻杆是广西岩溶地区常见的土著植物,在这两种土著植物较多的群落中,飞机草的入侵受到影响。本文通过分析发芽率、发芽速率和化感效应敏感指数等指标,研究了黄荆条和红背山麻杆的根、茎、叶三个部位不同浓度的水提液对飞机草种子萌发的影响,以检验这两种土著植物是否对飞机草具有化感作用。结果表明,与对照相比,红背山麻杆各部位不同浓度的水提液以及黄荆条的根、茎不同浓度的水提液对飞机草种子萌发有微弱的影响,整体表现出低促高抑的现象; 但黄荆条的叶原液对飞机草种子萌发抑制作用显著,在黄荆条叶原液处理下,飞机草发芽率仅为对照的20. 75% ,化感效应敏感指数为- 3. 8191。从生态效益和经济效益考虑,黄荆条可作为岩溶地区生物替代防治飞机草的优选植物。   相似文献   

峰峰矿区矿井突水分类及发生机理研究   总被引：2，自引：0，他引：2  

杨新安  程军  杨喜增 《地质灾害与环境保护》1999,10(2):24-29

在对峰峰矿区大量突水实例深入分析的基础上,根据隔水岩体初始特性即有无断层构造及其规模大小,将矿井突水分为完整隔水岩体突水、小断层破碎带突水及大断层突水三种类型。应用岩体变形与破裂机制和岩体水力学原理,对上述三种类型突水的发生机理进行研究,并讨论预防方法。  相似文献   

Agonistic interactions and dominance establishment in three crayfish species non-native to Europe     

《Limnologica》2019

Ecosystems increasingly face concurrent invasions by multiple species, but knowledge about relationships among invasive species is under studied. We examined agonistic encounters among signal crayfish Pacifastacus leniusculus, marbled crayfish Procambarus virginalis, and the common yabby Cherax destructor, none native to Europe, to assess the influence of aggression on their success in a sympatric environment. In interspecific interactions, similar-sized signal crayfish were significantly more likely to initiate aggressive encounters and won significantly more fights against similar-sized opponents. The marbled crayfish was the least aggressive and least successful in agonistic interactions. The mean number of fights, fight duration, and number and duration of low and high intensity fights varied significantly between intra- and inter-specific interactions, tending to be more pronounced in conspecific encounters. We concluded that crayfish species differ in fighting strategies employed during intra- and inter-specific interactions. Of the species evaluated, the signal crayfish shows the highest potential to establish dominance. However, factors such as growth rate, reproductive potential, ecosystem variables, and temperature of habitat may alter the competitiveness of an invader.  相似文献   

Changes associated with Phragmites australis invasion in plant community and soil properties: A study on three invaded communities in a wetland,Victoria, Australia     

《Limnologica》2017

Phragmites australis invasion is altering plant communities and therefore, soil properties have been changed significantly. This study compared the diversity among three communities in a wetland to assess the impact of invasion by Phragmites and the associated impact on soil properties. Three diversity indices, species richness (S), evenness (E) and Shanon-Weiner index (H) had significantly higher values in uninvaded plots compared to invaded in all the communities. Invaded plots had the lowest diversity, with H = 0 and Simpson’s index (D) = 1, (i.e. they were monospecific). These results support the idea that a reduction in diversity can be expected in wetlands colonized by Phragmites. Phragmites invasion significantly increased soil moisture, EC, phenolics, organic carbon, dehydrogenase activity and microbial biomass (C, N, P) with reduction of pH and arbuscular mycorrhizae fungi spore density compared with uninvaded zones. In addition, the study of antifungal phytochemistry of Phragmites elucidated the decrease of the competitive abilities of native plant Melaleuca ericifolia by interfering with formation of mycorrhizal associations and biomass. Our results suggest that Phragmites invasion has caused significant ecological alterations in communities by demonstrating a combined effect to plant diversity and soil variables.  相似文献   

西洞庭湖天然和人工改造湿地中克氏原螯虾(Procambarus clarkii)与日本沼虾(Macrobrachium nipponense)的食性差异     

谭文卓  李斌  王玉玉  肖雅渝  陆修远  杨梨萍  雷光春  蔡教慧  何木盈 《湖泊科学》2022,34(1):184-193

栖息地退化和外来物种入侵都是淡水生态系统中的主要威胁因素,因此,量化不同人类活动干扰强度下外来入侵生物和本土生物的食性组成差异,对于明确种间竞争强度,制定适合的管理对策至关重要.本研究应用碳、氮稳定同位素分析技术,比较了长江中下游西洞庭湖湿地受人类活动干扰程度不同的天然湿地和人工改造湿地中的入侵种克氏原螯虾(Procambarus clarkii)与本土种日本沼虾(Macrobrachium nipponense)的食性组成及差异.2017年8月8-18日在西洞庭湖区不同人类干扰强度的栖息地中采集了两种消费者和5种潜在食物来源样品,共计91个.测定碳氮稳定同位素含量后,使用贝叶斯混合模型,估算不同食物来源对消费者的贡献.研究发现:在两种栖息地中克氏原螯虾与日本沼虾食性均有重叠,且在改造湿地中重叠度更大.与克氏原螯虾相比,日本沼虾消费更多的动物性食物.与天然湿地相比,在改造湿地中由于克氏原螯虾数量更多,与本土种竞争食物资源,克氏原螯虾和日本沼虾δ¹³ C比值都显著升高,食性组成均发生了变化,植物性食物来源比重增加.由于食性改变,在改造湿地中仅日本沼虾δ¹⁵ N比值显著下降,克氏原螯虾在两种栖息地中δ¹⁵ N比值无显著变化.本研究证明,随着人类干扰强度增大,受干扰湿地中外来入侵生物对本土生物的影响增大.  相似文献   

富钾海绿石的新发现:钾肥资源的评价研究的新方向     

孟祥化 《化工矿产地质》1998,20(3):212-212

我国是一个人口众多的发展中国家,农业是国民经济的基础,农用钾肥主要都来自天然矿物资源,特别是我国东中部人口密集的主要农业基地的大部分省份,富钾的矿产资源十分贫乏。过去几十年来把蒸发盐建造的钾盐作为钾资源研究主要目标,到目前为止进展不大。根据最新矿产资...  相似文献   

麻黄山西探区淡水泥浆侵入电阻率测井特征分析及其应用     

赵永刚  潘和平 《地质科技情报》2012,31(1):106-109

麻黄山西探区大部分井的泥浆矿化度小于地层水矿化度,导致淡水泥浆侵入,影响电阻率测井值,使利用测井资料评价油水层存在较大的技术难度.在分析麻黄山西探区淡水泥浆侵入电阻率测井特征的基础上,对电阻率测井系列进行了合理选择,论述了径向电阻率比值法,并采用径向电阻率比值法计算含水饱和度,测井解释结果与试油资料对比表明,解释效果好,符合率高.  相似文献   

大庆油田高密度油包水钻井液技术研究与应用          下载免费PDF全文

刘永贵  胡志强  王俊杰  盖大众 《探矿工程》2014,41(12):24-26,30

针对大庆油田朝503区块地层压力高、地层流体活跃、水平井施工难度大的特点,通过室内实验,将原有的低粘高切油包水钻井液体系配方进行了改进完善,使其在密度上限达到2.00 g／cm^3时,油水比可控范围90∶10～75∶25,仍然具有良好的流变性、电稳定性和沉降稳定性。经过在朝42－平125井的应用,满足现场的施工要求,保证了井下安全。  相似文献