Long-term recovery of a Louisiana brackish marsh plant community from oil-spill impact: vegetation response and mitigating effects of marsh surface elevation   总被引：1，自引：0，他引：1  

Hester MW  Mendelssohn IA 《Marine environmental research》2000,49(3):233-254

Oil spills can have significant, short-term, negative impacts on coastal marshes, but the long-term effects and eventual recovery are not well documented, particularly in brackish marshes. The goals of this investigation were to: (1) document the long-term recovery of a Louisiana brackish marsh plant community impacted by a 1985 oil spill; (2) separate the effect of the oil spill on marsh deterioration from ambient rates of marsh deterioration; and (3) assess the relative importance of residual oil in the sediment and decreased marsh surface elevation in the failure of certain areas to recover. A total of 68 permanent plots previously established in 1985 were re-surveyed for plant and soil recovery in the fall of 1989. Although substantial (and near total) vegetative recovery was evident by significant increases in live and total vegetative cover, many of the plots that were initially heavily impacted by oil still displayed elevated levels of total saturated hydrocarbons in the soil. August 1990 measurements of plant photosynthetic response and edaphic variables revealed no significant differences between control plots and plots heavily impacted by oil that displayed vegetative regrowth. Rates of wetland land loss in the oiled marsh during an 8-year period that bracketed the time of the spill were within the historical range measured for this site and similar to the land loss rates of adjacent reference marshes. Results from a manipulative field transplant experiment indicated that the long-term failure of certain small areas to revegetate was primarily due to a decrease of marsh surface elevation (increased flooding stress), not a residual oil effect.  相似文献   

Phytoremediation of small-scale oil spills in fresh marsh environments: a mesocosm simulation     

Dowty RA  Shaffer GP  Hester MW  Childers GW  Campo FM  Greene MC 《Marine environmental research》2001,52(3):195-211

Research was conducted to assess the impact of oiling on fresh-marsh plant communities and to test the efficacy of techniques that may be used to enhance the bioremediation of crude oil spills in these environments while minimizing secondary anthropogenic impacts. To emulate field conditions, a mesocosm facility was used that houses 120 mesocosm vessels, each of 200-1 capacity. A five-way factorial treatment arrangement was used that included two substrates (inorganic, organic), two nutrient regimes (fertilized, not fertilized), two aeration levels (substrate aeration, no aeration), three oiling concentrations (0-, 5-, 10-1 m(-2) of South Louisiana Sweet Crude oil), and four vascular plant species (Alternanthera philoxeroides, Panicum hemitomon, Phragmites australis, Sagittaria lancifolia, and an unplanted control). Under the 5- and 10-1 m(-2) oiling concentrations, S. lancifolia displayed a short-term response of increased productivity, whereas P. hemitomon had the highest biomass production and photosynthetic rates at the end of the 18-month experiment. Overall plant growth and productivity, as well as oil degradation, were significantly higher in the inorganic substrate, indicating that biodegradation of oil spills in organic substrates may require a longer time period. Time-released fertilizer also stimulated plant productivity and resulted in higher soil respiratory quotients, suggestive of greater microbial activity, particularly in aerated mesocosms. The amount of oil remaining after 18 months was lowest in aerated and fertilized mesocosms containing either P. hemitomon or S. lancifolia and a substrate of low organic matter content.  相似文献   

红板岩材料隐式本构模型的建立及其应用研究     

邹光华  朱建明 《工程地质学报》2003,11(3):258-262

针对红板岩材料在岩土工程中所表现的大量模糊的和不确定的因素等特点,基于人工神经网络的学习能力,借助于室内岩石力学试验,进行了对该材料的力学本构特性进行了神经网络模拟研究,提出了隐式本构模型的思想和方法,并通过该方法对该岩石的流变试验结果进行学习,获得了以网络权值结构保存的力学特性知识,由此得到了表征红板岩应力应变本构关系的隐式本构模型。应用结果表明,该方法对岩土类材料本构关系的模拟研究具有很好的应用前景。  相似文献   

从埃及之行谈环境物探工作     

邹光华 《地质与勘探》2004,40(Z1):88-90

文章简要介绍作者在埃及之行中所接触到的生态环境问题,主要是:1.沙漠广布;2.阿斯旺水坝引起的生态环境变化;3.大气污染.进而从我国环境地质工作的战略地位出发提出应积极开拓环境物探工作的新领域,并简述已有成效的环境物探工作.  相似文献   

滤水管（Slug）试验数据的自动数字计算     

Kemb.  MW 郑孝玉 《水文地质工程地质译丛》1990,(1):37-41

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澳大利亚堪宁盆地礁组合的埋藏成岩作用     

Wall.  MW 黄思静 《国外地质(成都)》1993,(2):1-13,18

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智利Collahuasi盲铜矿的发现     

Dick  LA 邹光华 《物探化探译丛》1994,(2):32-35

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迎接挑战 研究对策     

邹光华 《物探与化探》1985,9(5):321-330

本文主要讨论在新的一轮普查中如何更加充分而有效地发挥物化探方法作用的一些问题。  相似文献   

矿床地质—地球物理模型     

邹光华 《物探化探译丛》1992,(4):111-117

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进一步推广应用计算机技术     

邹光华 《物探化探计算技术》1984,(1)

电子计算机的发明,已被美国未来学家托夫勒称作为人类进入第三次浪潮的标志,而所谓第三次浪潮即信息革命和知识革命的时代,这个阶段的特点是工业上以新兴电子工业、遗传工程、海洋工业、光导纤维等为基础。由于人类知识的发展速度越来越快,需要不断吸收更多的信息,信息结构产生了重大变化,社会信息的数量增长之快,令人震惊,在这种信息爆炸的情况下,为了解放  相似文献