快速监测评估废弃采石场生态恢复的研究

以北京门头沟区典型废弃石灰石矿山为例,通过野外调查、采样和实验室分析,计算得到废弃采石场植被与土壤自然演替之间关系.研究发现,TM影像中废弃采石矿场b3/b4波段比均值与废弃采石场综合恢复指数Irq之间具有较强的相关性,据其回归方程利用遥感手段快速评估计算得到研究区其他废弃采石矿场的综合恢复指数.可见,实地植被 - 土壤调查分析与空间遥感监测技术能够相互验证对采石场生态恢复状态的评估.     

月湖底栖动物的空间格局及其对水草可恢复区的指示

底质适宜是富营养湖泊恢复沉水植物(水草)的重要前提。大型底栖动物可综合指示底质的污染程度,于2002~2003年在武汉月湖开展了底栖动物水平分布对水草可恢复区指示作用的研究。首先通过月湖底栖动物与环境的相关分析,选择颤蚓科寡毛类作为底质营养状况的指示类群,然后利用同类湖泊群颤蚓与水草数据分析阈值,初步确定颤蚓密度≤100 ind/m2的底质适合水草生长,最后绘制月湖颤蚓分布的水平等值线,显示水草恢复的合适区域。在此基础上构建了应用底栖动物空间格局指示水草恢复区的技术原理框架。     

三峡库区森林植被恢复与可持续经营研究

系统的野外调查数据和历史资料分析结果表明,三峡库区森林植被在空间上发展不均匀,无明显垂直分带,且分布分散,人为干扰严重。目前,在70多个植被类型中,森林类型占25个,江岸两侧海拔800 m以下地区森林已经很少。森林类型中,马尾松、柏木林的分布面积最大,并在许多疏林中成为主要树种,主要是飞播或人工种植。库区大于25°的坡耕地占耕地面积的17.5％。库区薪炭林仅能满足农村用能总需求量的10.78％。不合理的土地利用方式和对森林的不合理砍伐导致脆弱的土壤系统和森林生态系统的严重退化、生产力下降和严重的水土流失。库区土壤年侵蚀量达到2.9亿t。三峡工程建设和移民安置对库区森林生态系统的压力和影响将是长期的。调查结果同时表明,库区植物生物多样性丰富,植物种类在5 032种以上,而且乡土树种多。分析认为,只要抓住三峡工程建设的契机,紧密结合国家天然林保护和退耕还林工程建设,充分利用良好的生物学基础,科学地封山育林,分带逐步恢复,同时,因地制宜,退耕还林,发展森林能源,建设多目标复合和多种模式并存的林业经营体系,发展经济,就能从根本上改善森林经营环境,实现森林恢复,形成合理布局的水库森林防护系统,促进三峡库区生态环境建设和可持续发展。     

温榆河氨氮污染控制措施的效果模拟

以城市退水为主要补给水源的北京市温榆河呈现以氨氮(18.68 mg·L-1)污染为主的特征.针对温榆河的水质改善需求,本研究以氨氮为目标污染物,采用QUAL2K河流水质模型和情景分析方法,对温榆河污染防治与水质改善措施的效果进行量化评估.模拟结果表明,提高污水厂的处理量和排放标准是改善温榆河水质的关键,可降低温榆河北关闸断面氨氮浓度29.66％;建设旁路离线河流净化器可削减5.57％的氨氮污染,是温榆河水质改善的有效措施.本研究提出的包括改善上游来水水质、干流截污、支流污染控制、污水厂提标改造、建设旁路离线河流净化器和生态河道等措施在内的综合实施方案,可使得温榆河的水质全程达到地表水V类标准.     

干旱荒漠区植被恢复与重建的探讨

西北干旱荒漠区生境严酷，物种贫乏，植被稀疏低矮，加上不合理的开发利用，致生境恶化。利用当地有限的水源来实现干旱荒漠区的植被恢复，防止流沙蔓延，可以从以下两方面入手：一方面，以裸地为立地条件，利用当地的关键种(keystone specics)或优势种(dominant species)，选择合适的生境，采用人工种子库和幼苗移植等方法，促使已缺失的植物种在目的地重新定居；另一方面，利用灌丛效应选择合适物种加以配合，提高干旱荒漠区的植被盖度。研究表明：以上两种途径对实现干旱荒漠区的植被恢复和重建是可行的。     

石油污染土壤的生物修复技术

石油污染土壤的生物修复技术具有高效、无二次污染和操作管理简便的优点，正逐步成为石油污染治理研究的一个重要领域。本从土壤中石油类物质降解了基本原理出发，总结了近年发展起来的强化生物降解效率的各种技术措施和工程方案及其适用条件，并在此基础上进一步分析了生物修复技术的发展方向和应用前景。中首先详细介绍了土壤中降解石油类物质的生物相组成及降解过程的基本生化原理，并指出影响微生物降解速率的因素主要有土壤pH值，温度、湿度、充氧量和各种营养物质及微量元素含量等。接着，重点重点阐述了石油污染土壤的非原位修复技术和原位修复技术并深入探讨了土地处理、生物堆积处理、堆肥处理等非原位修复技术和所采取的技术措施，主要包括应用高效降解微生物、投加氧化剂和表面活性剂等。最后，本还展望了石油类污染土壤生物治理的未来发展趋势。     

Effects of increased elevation and macro- and micronutrient additions onSpartina alterniflora transplant success in salt-marsh dieback areas in Louisiana

Spartina alterniflora was transplanted into dieback areas of a salt marsh in southeast Louisiana at two elevations (ambient and +30 cm) with and without macro- (N, P, and K) and micronutrient (Fe, Mn, Cu, and Zn) additions to determine if transplant success is dependent on increasing elevation or nutrients.Spartina alterniflora transplanted into elevated plots had more than twice the above- and belowground biomass as compared to nonelevated plots after three months of growth. Additionally, there was significantly more vegetative reproduction (greater culm density and number of newly produced culms) in elevated plots as compared to plots at ambient elevation. Macronutrient additions increased culm densities only in elevated plots.Spartina alterniflora transplanted into nonelevated plots had lower survival rates even when transplants received nutrient additions. These results suggest thatS. alterniflora may be transplanted successfully into degraded salt-marsh areas if elevation is increased. The addition of nutrients without a concomitant increase in elevation is not sufficient for transplant success.     

MULTICRITERIA EVALUATION IN A POLICY ANALYSIS OF A RHINE ESTUARY1

ABSTRACT: As part of a major project to provide the Rhine delta protection from North Sea floods, the Dutch installed sluices at Haringvliet in the late 1960s and converted the Haringvliet-Hollandsch Diep-Biesbosch (HHB) estuary into a tidally-damped, fresh-water system. Two decades later, the Dutch Rijkswaterstaat commissioned a study of alternative policies for managing the sluices and removing contaminated bottom sediments, including policies which would at least partially restore estuarine conditions to the HHB. This paper describes the public policy analysis comprising that study, focusing on the role played by formal mullicriteria evaluation (MCE), including the Analytic Hierarchy Process. Through the tasks of value-tree structuring, impact measurement, and criterion prioritization, the MCE influenced the entire structure of the analysis, became an integral part of it, and, despite initial skepticism among the participants about the utility of multicriteria analysis, was subsequently accepted and viewed favorably by the majority of them.     

WOODY VEGETATION AND RIPRAP STABILITY ALONG THE SACRAMENTO RIVER MILE 84.5–1191

ABSTRACT: Stability of vegetated and bare riprap revetments along a Sacramento River reach during the flood of record was assessed. Revetment damages resulting from the flood were identified using records provided by the U.S. Army Corps of Engineers and verified by contacts with local interests. Vegetation on revetments along a 35.6-mile reach was mapped using inspection records and stereo interpretation of aerial phoths taken shortly before and after the flood. A follow-up field inspection was conducted in September 1989. Revetment age, material, bank curvature, vegetation, and damage were mapped from a boat. Mapping results from both 1986 and 1989 were placed in a data base. About 70 percent of the bank line of the study reach was revetted. About two-thirds of the revetment was cobble; one-third was quarry stone. Revetment vegetation varied from none to large (> 50-inch diameter) cotton-woods. About 10 percent of the revetted bank line supported some type of woody vegetation. Damage rates for revetments supporting woody vegetation tended to be lower than for unvegetated revetments of the same age located on banks of similar curvature. Chisquared tests indicated damage rates were greater for older (pre-1950 construction) revetments, but were unable to detect differences based on vegetation or bank curvature. Research is needed to generate design criteria and construction techniques to allow routine use of woody plants in bank protection structures.     

Landscape ecological characteristics in temporal changes of riverside open space in urbanized area

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