A rationale for coastal wetland restoration through spoil bank management in Louisiana,USA

The rationale and outline of an implementation plan for restoring coastal wetlands in Louisiana is presented. The rationale for the plan is based on reversing the consequences of documented cause-and-effect relationships between wetland loss and hydrologic change. The main feature is to modify the extensive interlocking network of dredged spoil deposits, or spoil banks, by reestablishing a more natural water flow at moderate flow velocity (<5 cm/sec). Guidelines for site selection from thousands of potential sites are proposed. Examples of suitable sites are given for intermediate marshes. These sites exhibit rapid deterioration following partial or complete hydrologic impoundment, implying a strong hydrologic, rather than sedimentological, cause of wetland deterioration. We used an exploratory hydrologic model to guide determination of the amount of spoil bank to be removed. The results from an economic model indicated a very effective cost-benefit ratio. Both models and practical experience with other types of restoration plans, in Louisiana and elsewhere, exhibit an economy of scale, wherein larger projects are more cost effective than smaller projects. However, in contrast to these other projects, spoil bank management may be 100 to 1000 times more cost effective and useful in wetland tracts <1000 ha in size. Modest spoil bank management at numerous small wetland sites appears to offer substantial positive attributes compared to alternative and more intensive management at a few larger wetland sites.     

A conceptual framework for assessing cumulative impacts on the hydrology of nontidal wetlands

Wetlands occur in geologic and hydrologic settings that enhance the accumulation or retention of water. Regional slope, local relief, and permeability of the land surface are major controls on the formation of wetlands by surface-water sources. However, these landscape features also have significant control over groundwater flow systems, which commonly play a role in the formation of wetlands. Because the hydrologic system is a continuum, any modification of one component will have an effect on contiguous components. Disturbances commonly affecting the hydrologic system as it relates to wetlands include weather modification, alteration of plant communities, storage of surface water, road construction, drainage of surface water and soil water, alteration of groundwater recharge and discharge areas, and pumping of groundwater. Assessments of the cumulative effects of one or more of these disturbances on the hydrologic system as related to wetlands must take into account uncertainty in the measurements and in the assumptions that are made in hydrologic studies. For example, it may be appropriate to assume that regional groundwater flow systems are recharged in uplands and discharged in lowlands. However, a similar assumption commonly does not apply on a local scale, because of the spatial and temporal dynamics of groundwater recharge. Lack of appreciation of such hydrologic factors can lead to misunderstanding of the hydrologic function of wetlands within various parts of the landscape and mismanagement of wetland ecosystems.     

应用浮游植物对扎龙自然保护区水质的初步评价

通过对扎龙自然保护区水体中浮游植物调查及运用几种评价公式分析,评价结论为:扎龙水体浮游植物由8门60个属组成,数量在19 515×10~2～23 755×10~3个/升之间;水质属中污染型,同一年度污染情况为:8月>6月,北区>南区。     

长江口北支湿地资源和环境现状调查

调查了长江口支湿地环境现状，分析了评价长江口北支湿地的环境质量。指出，长江口北支湿地有着得天独厚的地理位置和自然条件，是世界范围内极具代表性十分重要的湿地，拥有丰富的水资源，动植物资源，滩涂资源等。近年来，由于长江上游河水质量下降，启东和海门经内河流向长江的城市生活污水，启东沿江建设的工业带，对北支口湿地环境质量产生了较大的影响。调查结果表明，长江口北支口水域主要污染物为COD，氨氮等，其污染程度呈现出以下规律：平水期（污染）＞丰水期（污染）＞枯水期（污染）。长江口北支区域陆地土壤中主要污染物为重金属元素镉，铅，锌以及滴滴涕，其中镉与滴滴涕达《土壤环境质量标准》（GB15618－1995）中三级标准，其他指标达一级标准。     

扎龙湿地的生态环境评价及防治对策

介绍了扎龙湿地的生态状况 ,并运用模糊数学对其生态状况给予评价 ,为做好扎龙湿地的生态保护工作 ,提出了相应的对策     

盐城市湿地园林建设初探

湿地园林是以湿地为对象的园林形式,为现代园林的一个组成部分,是利用现代园林建设和生态学原理,对湿地生态系统的保护、重建和恢复,艺术地再现自然湿地景现.在此,以湿地园林为研究对象,分析国内外湿地园林的发展概况,论述盐城市湿地园林建设的现状以及存在的问题,运用生态学和现代园林建设理论对盐城市湿地园林的建设进行初步的探索,较为详细的阐述其发展的规划目标以及建设的思路与对策,进一步强调湿地园林在建设城市大园林、改善生态环境方面的作用,并对湿地园林的未来进行展望.     

长江口九段沙湿地自然保护的探讨

九段沙是长江口新生沙岛，在调研其湿地生态环境和自然演变趋势基础上，尽快设立九段沙自然保护区已是各方共识，但对其而言，一方面已有大型工程的影响，另一方面滩地的冲蚀可能使高级群落－芦苇的分布面积减少，因此提出，在保护湿地初期建造，低堤不至于影响湿地的自然演变过程，而有利于保护高级群落和局部高潮滩的增速。     

鄱阳湖湿地管理对策研究

本文分析和研究了鄱阳湖湿地损失的原因和管理现状，提出了鄱阳湖湿地可持续发展的管理策略。     

Exports of dissolved ammonium (NH4 +) during storm events across multiple catchments in a glaciated forested watershed

Storm event exports of dissolved were explored for multiple events in the Point Peter Brook watershed (PPBW), a glaciated, forested watershed located in Western New York, USA. Investigations were performed across four catchments (1.6–696 ha) with varying topography and the extent of surface-saturated areas. While wetland and riparian waters were important sources of during non-storm periods, throughfall and litter leachate were the dominant contributors of during storm events. Ammonium concentrations in catchment discharge displayed a sinusoidal seasonal pattern with a maximum during early spring (March) and a minimum in late summer (August–September). Storm event concentrations of in streamflow were much greater than baseflow values and showed a consistent temporal pattern with an increase in concentrations on the hydrograph rising limb, a peak at or before the discharge peak, followed by a decline in concentrations. Storm event patterns of DON were similar to while the patterns of differed from for the summer and fall events. The storm event expression of was attributed to throughfall and throughfall-mediated leaching of the litter layer. The reactive behavior of precluded its use in an end member mixing model (EMMA) for predicting streamflow concentrations. While concentrations of in precipitation and streamflow were high for the spring events, exports of in streamflow were highest for the large and intense storm events. Baseflow concentrations increased with the percent wetland/saturated area in the catchment but the same trend did not hold for storm-event concentrations.     

西部湿地资源现状、问题及可持续发展研究——以四川省若尔盖高原湿地为例

湿地是水陆相互作用形成的独特生态系统,合理的开发利用将对西部开发中的生态环境建设直到巨大的作用。本文主要介绍我国西部湿地资源的基本情况、利用现状及存在问题,并以四川省若尔盖地区为例提出了西部湿地资源保护和可持续利用的科学对策。