涤纶高弹丝纤维球滤料过滤特性研究

采用自主研制的涤纶高弹丝纤维球滤料对景观水进行过滤试验,研究其过滤特性及相关因素对过滤性能的影响. 结果表明,在不投加任何絮凝剂,滤速为30 m/h,平均进水浊度为87.5 NTU时,纤维球滤料过滤周期达16.5 h左右,出水浊度维持在3～5 NTU.当PAFC投加量为12 mg/L,滤速为30～50 m/h,进水浊度为50～70 NTU时,过滤出水浊度可以维持在1 NTU以下,过滤周期达6 h以上,周期截污量为30～45 kg/m3. 采用气冲－气水联合反冲－水冲的反冲洗方式,当气冲强度为25 L/(s·m2),水冲强度为8 L/(s·m2)时,纤维球滤料积泥量约占滤料质量的4.53%.      

扎龙湿地沉积物垂向剖面中多环芳烃分布特征

对扎龙湿地核心区沉积物分层取样,以正己烷/二氯甲烷为提取剂,用超声波方法提取沉积物中16种优控PAHs,采用GC/MS法定量分析w(PAHs). 结果表明,扎龙湿地剖面沉积物中2环和3环PAHs占PAHs总量的86%以上,4环以上的PAHs所占比例较小. 在各层沉积物中含量较高的萘、菲、芴及PAHs总量随深度的增加而减小,沉积物表层0～10 cm内的w(PAHs)最高,达396.61 ng/g. 表层沉积物中含量较高的PAHs为萘>菲>芴>荧蒽>芘>二氢苊>苊烯>. w(PAHs)与沉积物中w(TOC)呈正相关关系,相关系数为0.9347. 从扎龙湿地的低环PAHs污染特征以及同周边地区大气颗粒物中的PAHs对照分析表明,扎龙湿地沉积物中的PAHs主要来源于石油类污染.      

长江口九段沙水域环境及生物体内多氯联苯分布

对长江口九段沙湿地自然保护区的滩涂水样、泥样以及水生生物体内的多氯联苯进行GC-MS检测,研究多氯联苯各单体在不同环境介质及生物体中的分布状况. 结果表明:水样、泥样中的多氯联苯检出率为100%,其中四氯联苯(PCB52)含量最高; 与其他河口地区相比,九段沙水域水体中多氯联苯(PCBs)含量处于中等水平,ρ(PCBs)为23～95 ng/L;滩涂泥样多氯联苯含量则较低,w(PCBs)为1.77～4.51 ng/g; 该水域水生生物多氯联苯检出率为100%,w(PCBs)为0.12～9.40 μg/kg,低于国家标准限量; 软体动物、甲壳类以及鱼类检出单体均以高氯类PCB118和PCB138为主,而非环境中含量较高的PCB52,反映了水生生物对于高氯类多氯联苯富集能力强于低氯类多氯联苯.      

Evaluation of a Market in Wetland Credits: Entrepreneurial Wetland Banking in Chicago

Abstract: With the rise of market‐led approaches to environmental policy, compensation for permitted discharge of dredge or fill material into wetlands under Section 404 of the U.S. Clean Water Act has been purchased increasingly from entrepreneurial third‐party providers. The growth of this practice (i.e., entrepreneurial wetland banking) has resolved many challenges associated with wetland compensation. But it has also produced (1) quantifiable temporal loss of wetland ecological functions, (2) spatial redistribution of wetland area, and (3) a degree of regulatory instability that may pose a threat to entrepreneurial compensation as a sustainable component of wetland‐compensation policy. We used achieved compensation ratios, lapse between bank credit sale and the attainment of performance standards, distance between impact and bank site, and changes in bank market area to examine these 3 factors. We analyzed data from a census of all such transactions in the Chicago District of the U.S. Army Corps of Engineers, compiled from site visits, Corps databases, and contacts with consultants and Section 404 permittees. Entrepreneurial banking provided compensation at a lower overall ratio than nonbank forms of compensation. Approximately 60% of bank credits were sold after site‐protection standards were met but before ecological performance standards were met at the bank site. The average distance between bank and impact site was approximately 26 km. The area of markets within which established banks can sell wetland credits has fluctuated considerably over the study period. Comparing these data with similar data for other compensation mechanisms will assist in evaluating banking as an element of conservation policy. Data characterizing the performance of entrepreneurial wetland banks in actual regulatory environments are scarce, even though it is the most established of similar markets that have become instrumental to federal policy in administering several major environmental protection laws.     

The Combined Effects of Remnant Vegetation and Tree Planting on Farmland Birds

Abstract:  Biodiversity conservation on agricultural land is a major issue worldwide. We estimated separate and joint effects of remnant native woodland vegetation and recent tree plantings on birds on farms (approximately 500–1000 ha) in the heavily cleared wheat and sheep belt of southern Australia. Much of the variation (>70%) in bird responses was explained by 3 factors: remnant native-vegetation attributes (native grassland, scattered paddock trees, patches of remnant native woodland); presence or absence of planted native trees; and the size and shape of tree plantings. In terms of the number of species, remnant native vegetation was more important than tree planting, in a 3:1 ratio, approximately. Farms with high values for remnant native vegetation were those most likely to support declining or vulnerable species, although some individual species of conservation concern occurred on farms with large plantings. Farm management for improved bird conservation should account for the cumulative and complementary contributions of many components of remnant native-vegetation cover (e.g., scattered paddock trees and fallen timber) as well as areas of restored native vegetation.     

Conserving Biodiversity and Ecosystem Function through Limited Development: an Empirical Evaluation

Abstract:  Suburban, exurban, and rural development in the United States consumes nearly 1 million hectares of land per year and is a leading threat to biodiversity. In response to this threat, conservation development has been advanced as a way to combine land development and land conservation while providing functional protection for natural resources. Yet, although conservation development techniques have been in use for decades, there have been few critical evaluations of their conservation effectiveness. We addressed this deficiency by assessing the conservation outcomes of one type of conservation development project: conservation and limited development projects (CLDPs). Conducted by land trusts, landowners, and developers, CLDPs use revenue from limited development to finance the protection of land and natural resources. We compared a sample of 10 CLDPs from the eastern United States with their respective baseline scenarios (conventional development) and with a sample of conservation subdivisions—a different conservation development technique characterized by higher-density development. To measure conservation success, we created an evaluation method containing eight indicators that quantify project impacts to terrestrial and aquatic ecosystems at the site and in the surrounding landscape. The CLDPs protected and managed threatened natural resources including rare species and ecological communities. In terms of conservation benefits, the CLDPs significantly outperformed their respective baseline scenarios and the conservation subdivisions. These results imply that CLDPs can offer a low-impact alternative to conventional development and a low-cost method for protecting land when conventional conservation techniques are too expensive. In addition, our evaluation method demonstrates how planners and developers can incorporate appropriate ecological considerations when designing, reviewing, and evaluating conservation development projects.     

Habitat Use and Life History as Predictors of Bird Responses to Habitat Change

Abstract:  In theory the consideration of life-history characteristics should provide a way of making predictive generalizations about the responses of different species to environmental modification. Nevertheless, few studies have tested the validity of this assumption or attempted to apply it across large numbers of related species. We explored both quantitative and qualitative contrasts between species of waterbirds that have either expanded or contracted their ranges in southern Africa over the past 40 years to test the hypothesis that expansionists and contractionists, respectively, should share life-history characteristics and/or ecological attributes. Similarities and differences in life history and ecology were explored through multivariate statistics. Overall, life-history traits provided an inadequate explanation of whether species would be range expansionists or contractionists. By contrast, ecological attributes of species that related to habitat use correlated well with range changes. In particular, waterbird species that inhabit pans seemed to be preadapted to using human-made dams and impoundments. The ability of many species to use artificial wetlands has aided their westward range expansions into arid regions of southern Africa. By contrast, species that rely on vegetated wetlands and that require reeds for nesting were predisposed to range contraction because their habitats have been severely affected by agricultural development and urbanization. In direct contrast to range expansions, most range contractions were west to east, the eastward contraction reflected the high level of wetland loss and degradation in the eastern lowlands of South Africa. Based on analysis of ecological attributes of regional contractionists, several additional species were identified as of potential conservation concern, although such concern may not as yet have been expressed.     

复合垂直流人工湿地基质氧化还原酶活性研究

对复合垂直流人工湿地系统(IVCW)基质中5种常见的氧化还原酶活性进行了研究.结果表明,氧化还原酶活性存在显著性季节差异,过氧化物酶在春、夏、秋三季的酶活性显著高于冬季的酶活性(P＜0.05);多酚氧化酶和过氧化氢酶的活性最高在秋季;脱氢酶在夏、冬两季时酶活性显著高于秋季和春季的酶活性(P＜0.05);硝酸盐还原酶在春、冬季时显著高于夏、秋季(P＜0.01).空间分布上,除过氧化物酶外,湿地下行流池的酶活性显著高于上行流池,并且随着基质深度的增加递减;但基质硝酸盐还原酶各层之间差异不显著.图6表3参17     

江苏泗洪洪泽湖湿地自然保护区生态服务功能价值评估

在野外实际调查基础上,运用市场价值、影子工程、旅行费用等方法对江苏泗洪洪泽湖湿地自然保护区生态服务功能进行价值评估.结果显示,该保护区生态服务功能年均总价值约为13.97亿元,占泗洪县2005年国民生产总值的20.82%.重要物种栖息地、水分调节以及大气调节生态服务功能价值分别占总价值的27.49%、25.27%、19.33%,是该保护区的主要核心服务功能.泗洪湿地单位面积生态服务功能价值为28 299元·hm-2·a-1,分别为全球和中国湿地平均单位价值的4.09倍、4.85倍.在发展当地经济过程中,必须从该保护区湿地生态系统的基本特征出发,科学合理地保护、开发湿地资源.     

人工湿地基质磷吸附特性与其物理化学性质的关系

对9种垂直流人工湿地基质进行了对磷的等温吸附试验.结果表明,在溶液磷浓度为100～500mg/L条件下,9种基质中以草炭的吸附量为最高,达到2439.56mg/kg;砾石的吸附量最低,仅为188.67mg/kg;其余基质表现出高炉渣土>高炉渣>煤灰渣土>耕层土>煤灰渣>中粗砂土>中粗砂的规律.供试基质的容重和密度与磷吸附量呈极显著性负相关关系;基质的颗粒直径D₈₀和不均匀系数K₈₀与磷吸附量呈显著性正相关关系.基质的CEC、有机质、有效Fe和交换性Al的含量与磷吸附量呈极显著性正相关关系;pH值与磷吸附量呈极显著性负相关关系.