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471.
克隆整合提高了入侵植物空心莲子草对北美车前的竞争力 总被引:4,自引:0,他引:4
选取北美车前Plantago virginica L.为竞争背景草,以空心莲子草Alternanthera philoxeroides(Mart.)Griseb.为研究对象,通过切断或保持其先端分株与后端分株间的匍匐茎连接,研究了克隆整合对先端分株生长以及竞争力的影响。结果显示:不管是否存在竞争,克隆整合显著提高了空心莲子草先端分株的生物量、总匍匐茎长度、叶片数目和分株数目,并降低了其对茎的生物量投资。此外,克隆整合显著提高了空心莲子草先端分株对北美车前的竞争力。种间竞争显著降低了空心莲子草的生长,但并没有显著影响其生物量分配。上述结果表明,克隆整合在一定程度上能够促进入侵克隆植物的生长和竞争力,从而可能潜在影响其入侵性。 相似文献
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473.
In order to investigate the effects of clonal integration on the adaptation of clonal plants to the environmental stress of homogeneous herbivory, we conducted a greenhouse experiment to investigate the ecophysiological response characteristics of Phalaris arundinacea collected from the riparian zone of the Poyang Lake wetland and Le'an River in Jiangxi Province and the effect of clonal integration on this dominant plant under two-months of simulated cyclical homogenous herbivory. Simulated herbivory strength was set at four different levels: no leaf removal (control) and 25%, 50%, and 75% leaf removal. We implemented two methods of clonal integration including no integration, in which the rhizome connection was severed, and integration, in which the rhizome connection was intact. We found that simulated herbivory significantly decreased the number of leaves, total shoot length, number of ramets, and biomass of P. arundinacea (P < 5%), regardless of whether the rhizomes were intact or severed. Ramets with severed rhizome connections (RRC) generally had higher growth indices than those with intact rhizome connections (RIC). Severing rhizomes did not significantly affect the chlorophyll content of P. arundinacea, while RRC under simulated herbivory intensities of 25% and 50% leaf removal had higher chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (Chlt) contents than RIC did, and simulated herbivory increased the chlorophyll contents of all ramets. RRC net photosynthesis rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and transpiration rate (Tr) were all higher in RRC than they were in RIC under simulated herbivory intensities of 50% and 75% leaf removal; however, the opposite relationship was observed under a simulated herbivory intensity of 25% leaf removal. Further, simulated herbivory limited the photosynthetic index of P. arundinacea. These effects resulted in an inadequate accumulation of nutrients in the plant. Phalaris arundinacea can adapt to simulated herbivory treatments in terms of growth, but clonal integration cannot improve the growth of P. arundinacea under a homogeneous herbivory treatment. © 2018 Science Press. All rights reserved. 相似文献
474.
The transition to full democracy in South Africa in 1994 saw local government becoming the focal point for dealing with socio-economic development needs of communities. The Integrated Development Plan (IDP) has been used as the tool for guiding local development objectives, balanced against environmental demands within a sustainable development paradigm. Here we examine the extent to which this is being achieved through an analysis of IDPs from 35 different municipalities at three scales. We test the hypothesis that the metropolitan municipalities are better at mainstreaming environmental issues into their IDPs than local and district municipalities. Results indicate that mainstreaming environmental issues in IDPs is still low. The hypothesis that metropoles are better at mainstreaming environmental issues than district and local municipalities was not accepted since there were no significant differences between municipalities. There was low relative budget allocations and inclusion of vision and mission statements that mainstream environmental issues in all municipalities. For mainstreaming of environmental issues to be effective in IDPs, both proactive approaches and multi-faceted bottom-up and top-down approaches are suggested. 相似文献
475.
张乐勤 《环境与可持续发展》2021,46(1)
本文采用主成分分析方法,测算了长三角一体化区域经济发展与环境负荷系统综合指数;运用耦合协调模型,对两系统耦合协调度进行了考察;依据耦合协调度,构建了绿色发展能力判别标准,据此对绿色发展状态进行了识别;基于基尼系数方法,对绿色发展状况均衡性进行了探索。结果表明:(1)安徽、浙江、江苏、上海的经济发展指数分别由2005年的0.41、0.41、0.46、0.44跃升至2017年的0.81、0.72、0.85、0.84,环境负荷指数分别由2005年的0.91、0.91、0.90、0.84降至2017年的0.58、0.51、0.55、0.44;(2)研究时段内,安徽、浙江、江苏、上海的耦合协调度均值分别为0.7677、0.7667、0.7688、0.7691,均呈准绿色发展状态;(3)考察时序内,长三角一体化区域绿色发展能力基尼系数均值为0.0129,准绿色发展能力均衡。基于研究结果,提出了提升长三角一体化区域绿色发展能力的政策建议。 相似文献
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477.
海岸带地区是陆海交互作用区,是陆海统筹中需要重点关注的区域,党的十九大报告里提出要坚持陆海统筹,《深化党和国家机构改革方案》中提出整合原环境保护部等部委的相关污染防治和生态保护执法及国家海洋局的海洋环境保护职责,组建生态环境部。本研究通过对厦门市陆海统筹政策现状系统梳理分析,厘清生态环境建设中陆海统筹的关键问题,总结出陆海统筹工作的对策建议,包括构建生态环境陆海统筹管理新模式、蓝色经济与生态文明协同发展新模式、基于绿色发展的弹性海岸新模式、"三个一"智慧海岸带大数据信息系统技术新体系等。这些对策对于我国海岸带城市区域生态环境建设的陆海统筹和海岸带综合管理工作具有借鉴意义。 相似文献
478.
Management of Kruger National Park (KNP) has recently made considerable progress in developing new policies to address biodiversity conservation and management challenges. These include tourism, water provision and elephant management policies. This study examines the integration of these three policies with regard to biodiversity conservation and management. Findings indicate that in their current fragmented form, the three policies actually undermine opportunities for effective biodiversity conservation and management in the KNP. This can be reversed by adopting a new management approach based on an environmental matrix organizational framework. Such a framework provides a mechanism for integrated policymaking and implementation and for improving biodiversity conservation and management in the KNP. The study concludes that an integrated approach is necessary due to the interlinkages between policies that affect biodiversity conservation at the KNP. 相似文献
479.
There is a recognised need to integrate multiple toxicity data deriving from battery bioassays into an easily understandable and single value, which may facilitate the decision-making process related to the management of contaminated sediments. In this study, two integration results systems were applied and compared: toxicity classification system (TCS) and Toxicity Test Battery integrated Index (TBI). The quality of sediments of the Taranto seas (Mar Grande and Mar Piccolo) was assessed by a battery of five test species representing different trophic levels (Dunaliella tertiolecta, Tigriopus fulvus, Corophium insidiosum, Mytilus galloprovincialis, and Anphibalanus amphitrite) and performed on three exposure phases (elutriate, porewater, and whole sediment). The integration of biological tests results with TBI showed that stations located in Mar Grande and one station in Mar Piccolo were in the high ecotoxicological risk level, according to the results obtained with TCS. The comparison of results deriving from two evaluation systems showed similarity in the ecotoxicological risk level. Only in one case there was a lack of concordance between two indices giving opposite judgments. The present study demonstrates that the use of one of the two indices can be useful to estimate and to rank hazard level for sediments. 相似文献
480.
利用荧光区域积分结合物料平衡计算及多元直接梯度分析,考察强化除磷-硫自养系统对低COD/TN比市政污水中有机物、氮和磷污染物的去除特性.结果表明,在进水COD/TN比为4.5~6.0的条件下,强化除磷-硫自养系统出水中的TN、NH4+-N和TP浓度分别降至1.31、1.11和0.23mg/L,其去除率分别达到了96.3%、96.0%和86.9%.强化除磷-硫自养系统对荧光区域Ⅰ~Ⅴ标准积分体积的去除率分别为73.7%、64.3%、50.6%、61.3%和28.1%.物料平衡计算表明,非曝气区对荧光区域Ⅰ、Ⅱ和Ⅳ的物质有明显的去除效果;好氧区对荧光区域Ⅰ、Ⅱ和Ⅲ的物质有明显的去除效果.多元直接梯度分析表明,磷的释放过程可能与溶解性微生物代谢产物荧光区中的有机物相关,而自养的硝化反应、吸磷过程和有机物的去除可在好氧区达到统一. 相似文献