扬州市不同功能区表层土壤中多环芳烃的含量、来源及其生态风险

对扬州市6个不同功能区（公园、菜地、文教区、居民区、加油站和工业区）共59个表层土壤样品（0~10 cm）中15种美国环境保护署优控的多环芳烃（PAHs）的含量和来源进行了分析,并利用苯并[a]芘（BaP）毒性当量浓度（TEQ_BaP）评价了土壤中PAHs的生态风险.结果表明,扬州市土壤中Σ15PAHs总量范围为21~36118 μg·kg^-1,中值为295 μg·kg^-1,PAHs组成中以4~6环为主.不同功能区Σ15PAHs总量平均值高低顺序为工业区 > 加油站 > 文教区 > 菜地 > 居民区 > 公园.相关性分析表明,整个扬州市土壤中Σ15PAHs总量与土壤总有机碳（TOC）（P<0.05）和黑碳（BC）（P<0.01）含量都呈显著性正相关,但除了加油站土壤中Σ15PAHs总量与BC含量呈显著性正相关（P<0.01）外,不同功能区土壤中Σ15PAHs总量与TOC、BC含量都无显著相关性.特征比值法结果表明,不同功能区土壤中PAHs来源虽有些差异,但都主要来源于石油泄漏以及石油、煤和生物质等的燃烧.扬州市土壤中15种PAHs总TEQ_BaP值的范围是2~4448 μg·kg^-1.以荷兰土壤环境标准中的10种PAHs总TEQ_BaP值33 μg·kg^-1为标准,扬州市有45.8%的土样超标,各功能区点位超标率高低顺序为工业区（70%） > 加油站（60%） > 文教区（55.6%） > 菜地（50.0%） > 居民区（30%） > 公园（10%）.因此,扬州市不同功能区中都有部分表层土壤存在潜在的生态风险,工业区和加油站风险相对较高,而居民区和公园风险相对较低.     

生物炭输入对不同滨岸带土壤营养元素有效态变化的影响

生物炭作为一种新型环保材料常被用于改良土壤和污染修复,生物炭输入对土壤中营养元素的有效态会产生明显影响.本文基于太湖滨岸带不同土地利用类型(林地、草地、耕地和荒地),对比研究生物炭施加对不同类型土壤中营养元素有效态含量的影响,并探讨其动力学变化规律.结果表明,生物炭施加能够明显影响滨岸带土壤营养元素有效态含量,但对碳氮磷的影响效果存在差别.添加生物炭之后,土壤中溶解性有机碳呈显著下降趋势,而有效氮轻微增加,有效磷则明显增加.林地、草地、耕地和荒地土壤中溶解性有机碳含量分别下降了33. 3%、27. 4%、29. 5%和51. 4%;有效氮含量分别提高了10. 8%、18. 2%、16. 4%和15. 2%;有效磷含量分别增加了40. 0%、50. 2%、34. 0%和43. 6%.对比控制组(CK)和添加组(BC)的变化,土壤溶解性有机碳和有效磷含量在两组之间差别不大,而有效氮的含量变化差距较大,且在4种利用类型土壤中,生物炭施加后对不同营养元素有效态的影响程度有所差异.     

湿润亚热带山地表土植硅体指示的垂直植被变化——以福建戴云山为例

表土植硅体组合与其上覆植被类型之间的关系研究是利用植硅体进行古气候和古植被重建的基础.选取位于湿润亚热带地区的戴云山作为研究对象,沿海拔梯度以50?—?100 m为间隔共采集21个表土样品,以探讨该地区表土植硅体组合对山地植被的指示意义.结果表明:戴云山表土植硅体含量丰富,类型多样,主要以禾本科类植硅体占优势;此外,随着海拔的升高,表土植硅体组合中哑铃型和短鞍型百分含量快速增加,而扇型和长鞍型,特别是木本类植硅体的百分含量则逐渐减少,指示了山地植被从温性针叶林向常绿灌丛林的过渡,说明戴云山表土植硅体组合能够反映山地垂直植被带变化的主要特征;植硅体类型主成分分析(PCA)结果显示位于湿润亚热带地区的戴云山表土植硅体组合变化可能主要受温度的控制.本研究为今后在湿润亚热带山地地区开展古气候和古植被重建研究提供了重要的基础资料.     

三峡库区消落带土壤中重金属铬调查与分析

报道了三峡库区长江干流及小江支流消落带土壤重金属铬含量背景值调查结果。结果表明目前土壤未被重金属铬污染。     

Integrating Nonindigenous Aquatic Plant Control with Protection of Snail Kite Nests in Florida

The endangered snail kite (Rostrhamus sociabilis) feeds primarily on the freshwater apple snail (Pomacea paludosa) in Florida. The nonindigenous, floating water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes) impede kites from finding snails. Effective control of these aquatic plants in the littoral zone of central and south Florida lakes benefits kites by maintaining open foraging habitat. However, incidental herbicide spraying of nesting substrates result in nest collapse when kites breed in nonwoody, emergent plants [cattail (Typha spp.) and giant bulrush (Scirpus validus)] in the outer littoral zone during lower lake levels. Many endangered species recovery plans and their implementation have experienced problems due to inaction and/or noncooperation by various governmental agencies and their personnel. Herein, we describe the development and implementation of a buffer zone strategy to prevent secondary impacts from an aquatic plant control program to snail kites nesting on lakes in central and south Florida. A strategy was jointly developed by personnel of five state and federal agencies to control herbicide application near kite nesting areas during the normal breeding season. Although requiring various modifications during its implementation, this cooperative effort successfully integrated aquatic plant control objectives with snail kite conservation on Lake Okeechobee during 1988. The program was expanded the following year to lakes Kissimmee and Tohopekaliga. Since the implementation of the snail kite impact preclusion program, no nest loss was attributed to incidental herbicide applications on lakes Okeechobee, Kissimmee, and Tohopekaliga.     

ENVIRONMENTAL AUDITING: Which Birds Are Useful Bioindicators of Mining and Grazing Impacts in Arid South Australia?

Significant annual variations in population size of most species were evident with greater abundance of most species in wet years. Habitat variables, particularly vegetation structure, were also an important determinant of the abundance of most bird species and tended to mask the impacts of the land use under investigation. Several bird species had benefited from the provision of permanent water at mining and pastoral sites. Other species utilized increased nesting or feeding opportunities associated with the mining operation and increased food supply at the pastoral sites. Crested bellbirds and mixed-feeding flocks of small insectivorous birds were apparently disadvantaged by mining and hence may be useful bioindicators of mining impacts. No bird species or community parameters were identified which could serve as useful early warning bioindicators of pastoral impacts.     

RESEARCH: Land Use Characteristics and Water Quality: A Methodology for Valuing of Forested Buffers

In this study, water quality and basin characteristics data from different basins of the Fish River basin, Baldwin County, Alabama, were used to develop a valuation model. This valuation model is based on the effectiveness of “contributing zones” identified and delineated using methods described by Basnyat and others (Environmental Management]1999] 23(4):539–549). The “contributing zone” delineation model suggests that depending on soil permeability, soil moisture, depth to water table, slope, and vegetation, buffer widths varying from 16 m to 104 m must be maintained to assimilate or detain more than 90% of the nitrate passing through the buffers. The economic model suggests the value of retiring lands (to create the buffers) varies from $0 to $3067 per ha, depending on the types of crops currently grown. The total value of retiring all areas identified by the contributing zone model is $1,125,639 for the study area. This land value will then form the basis for estimates of the costs of land management options for improving (or maintaining) water quality throughout the study area.     

“Protecting coastal zones in the Mediterranean: an economic and regulatory analysis”

This paper examines existing measures taken to protect the coastal zones of the Mediterranean Sea and assesses their success. A summary of the main pressures facing this region is given, followed by an analysis of the legislation covering coastal zone development in ten countries: Algeria, Croatia, Egypt, France, Israel, Italy, Malta, Spain, Tunisia and Turkey. The paper finds that not all of these States have legislation specifically covering coastal zones, but there is concern in all areas that existing legislation is not working. The costs and benefits of controlling coastal development are examined. Firstly, a literature review of valuation studies identifies a range of values placed on the developed and undeveloped coastline for both users and local property owners. These values were then used in a model to evaluate policy options to control development of a stretch of coastline. The model indicates that a stricter control regime of coastal development may provide significant benefits.

基于GIS的厦门市沿海岸线景观生态规划

根据景观生态学的基本原理和方法,运用GIS技术与因子加权叠加法,对厦门市沿海岸线进行了多目标的景观生态适宜性分析,并依据城市发展规划对沿海岸线及近岸海域的发展要求,提出厦门市沿海岸线及近岸海域的景观生态规划方案。该方案为促进厦门市经济发展和生态环境保护,创建“海湾型生态城市”提供了科学依据,并对我国城市沿海岸线的生态规划具有一定的参考意义。     

新型膜-生物反应器在不同通量下的膜污染特性研究

选择适当的膜通量是膜-生物反应器控制膜污染的有效手段之一.本文根据膜通量与临界通量的关系选取了5个不同的膜通量,考察在这些通量条件下新型膜-生物反应器膜污染发展特性的变化.试验结果表明,膜通量的变化会影响膜污染的发展特性.当膜通量小于临界通量区时,膜污染发展具有"2阶段"趋势,并且膜通量越小"第1阶段"和"第2阶段"的膜污染发展速率对比越显著.当膜通量在临界通量区通量内时,首先出现短暂的膜污染快速增长期,随后膜污染发展仍呈现"2阶段"现象.当膜通量大于临界通量区通量时,膜操作压力(TMP)从开始运行即迅速上涨直至试验结束.