Linking Hydrologic Alteration to Biological Impairment in Urbanizing Streams of the Puget Lowland,Washington, USA1

Abstract: We used a retrospective approach to identify hydrologic metrics with the greatest potential for ecological relevance for use as resource management tools (i.e., hydrologic indicators) in rapidly urbanizing basins of the Puget Lowland. We proposed four criteria for identifying useful hydrologic indicators: (1) sensitive to urbanization consistent with expected hydrologic response, (2) demonstrate statistically significant trends in urbanizing basins (and not in undeveloped basins), (3) be correlated with measures of biological response to urbanization, and (4) be relatively insensitive to potentially confounding variables like basin area. Data utilized in the analysis included gauged flow and benthic macroinvertebrate data collected at 16 locations in 11 King County stream basins. Fifteen hydrologic metrics were calculated from daily average flow data and the Pacific Northwest Benthic Index of Biological Integrity (B‐IBI) was used to represent the gradient of response of stream macroinvertebrates to urbanization. Urbanization was represented by percent Total Impervious Area (%TIA) and percent urban land cover (%Urban). We found eight hydrologic metrics that were significantly correlated with B‐IBI scores (Low Pulse Count and Duration; High Pulse Count, Duration, and Range; Flow Reversals, T_Qmean, and R‐B Index). Although there appeared to be a great deal of redundancy among these metrics with respect to their response to urbanization, only two of the metrics tested – High Pulse Count and High Pulse Range – best met all four criteria we established for selecting hydrologic indicators. The increase in these high pulse metrics with respect to urbanization is the result of an increase in winter high pulses and the occurrence of high pulse events during summer (increasing the frequency and range of high pulses), when practically none would have occurred prior to development. We performed an initial evaluation of the usefulness of our hydrologic indicators by calculating and comparing hydrologic metrics derived from continuous hydrologic simulations of selected basin management alternatives for Miller Creek, one of the most highly urbanized basins used in our study. We found that the preferred basin management alternative appeared to be effective in restoring some flow metrics close to simulated fully forested conditions (e.g., T_Qmean), but less effective in restoring other metrics such as High Pulse Count and Range. If future research continues to support our hypothesis that the flow regime, particularly High Pulse Count and Range, is an important control of biotic integrity in Puget Lowland streams, it would have significant implications for stormwater management.     

曹妃甸围填海土壤重金属积累的磁化率指示研究

环境磁学方法在土壤重金属污染识别中被广泛运用,其具有简单、快速、无破坏性和灵敏度高的特点.本研究以北方典型的围填海区——曹妃甸工业区土壤为例,开展土壤磁化率对重金属积累的指示研究.根据研究区的土地功能规划特征,将研究区土壤分为工业区土壤、生活区土壤以及自然滩涂和湿地土壤共3类.共采集35个表土(0~10 cm)样品和3个土壤剖面柱状样,分析土壤中的磁化率(χlf)、铁(Fe_2O_3)含量及重金属(Cr、Ni、Cu、Zn、As、Pb、Mn、V)元素含量.结果表明:工业区表土磁化率和重金属含量空间分异性较高,受工业生产的影响明显;工业区和生活区剖面中0~20cm的表层土壤中,各重金属均出现不同程度的富集现象,而远离工业区的潮滩剖面中重金属含量变化不明显.研究区表土磁化率与重金属含量总体上有相关性:其中工业区表土磁化率与Fe_2O_3、Ni、Cu、As和V呈现极显著(P0.01)正相关,可以作为指示土壤重金属积累的指标.但在生活区和自然潮滩湿地土壤中,土壤磁化率的高低不能很好地指示重金属的积累情况,推测可能与土壤中磁性物质来源以及潮滩湿地的环境条件有关.     

基于生命周期评价的烧结烟气净化技术比较

烧结烟气是钢铁企业主要污染源之一,活性炭同时脱硫脱硝技术和半干法脱硫+SCR脱硝组合净化技术是目前实现烧结烟气综合净化处理较成熟的方案。运用生命周期评价手段,对国内某钢铁企业2种烟气净化技术进行综合评价。通过收集能源消耗、资源消耗和污染物排放清单,确定能耗分布,并计算得到相应的资源耗竭系数和环境影响负荷。结果表明:能源消耗和资源消耗方面,活性炭法优势明显,能耗和资源耗竭系数仅为半干法脱硫+SCR脱硝组合净化技术的68.38%和59.33%;环境影响方面,二者差距较小,活性炭法环境影响负荷略小。最后,依据生命周期评价结果给出相应建议,综合2种烟气净化技术生命周期评价结果,从能耗、资源消耗和环境影响的角度来看,活性炭法在烧结烟气净化领域具有明显的优势。     

Assessing coastal vulnerability to climate change: comparing segmentation at global and regional scales

Recent concerns about potential climate-change effects on coastal systems require the application of vulnerability assessment tools in order to define suitable adaptation strategies and improve coastal zone management effectiveness. In fact, while various research efforts were devoted to evaluate coastal vulnerability to climate change on a national to global level, fewer applications were carried out so far to develop more comprehensive and site-specific vulnerability assessments suitable to plan possible adaptation measures at the regional scale. In this respect, specific indicators are needed to address climate-change-related issues for coastal zones and to identify vulnerable areas at the regional level. Two sets of coastal vulnerability indicators were selected, one for regional and one for global studies, respectively, concerning the same features of coastal systems, including topography and slope, geomorphological characteristics, presence and distribution of wetlands and vegetation cover, density of coastal population and number of coastal inhabitants. The proposed set of indicators for the regional scale was chosen taking into account the availability of environmental and territorial data for the whole coastal area of the Veneto region and was based on site-specific datasets characterized by a spatial resolution appropriate for a regional analysis. Moreover, a GIS-based segmentation procedure was applied to divide the coastline into linear segments, homogeneous in terms of vulnerability to climate change and sea-level rise at the regional scale. This approach allowed to divide the Veneto shoreline into 140 segments with an average length of about 1 km, while the global scale approach identified four coastal segments with an average length of about 66 km. The performed comparison indicated how the more detailed approach adopted at the regional scale is essential to understand and manage the complexities of the specific study area. In fact, the 25-m DEM employed at the regional scale provided a more accurate differentiation of the coastal area's elevation and thus of coastal susceptibility to the inundation risks, compared to the 1-km DEM used at the global level. Moreover, at the regional level the use of a 1:20,000 geomorphological map allowed to differentiate the unique landform class detected at the global level (e.g., fluvial plain) in a variety of more detailed coastal typologies (e.g., open coast eroding sandy shores backed by bedrock) characterized by a different sensitivity to climate change and sea-level rise. Accordingly, the information provided by regional indicators can support decision-makers in improving the management of coastal resources by considering the potential impacts of climate change and in the definition of appropriate actions to reduce inundation risks, to avoid the potential loss of valuable wetlands and vegetation and to plan the nourishment of sandy beaches subject to erosion processes.     

丹江口水库蓄水后汉江中下游水文时空变化的#br# 定量评估及其生态影响

采用变化范围法（RVA）定量研究了丹江口水库蓄水后汉江中下游水文情势的时空变化,评估出汉江干流变化度最大的江段和水文特征指标类别,分析了其对应的生态影响,并针对汉江流域的四大家鱼和水华问题进行了敏感水文指标的变化度分析。结果显示:丹江口大坝蓄水后,汉江下游河道流量是中变化度占主导,比例范围为47～63%;水位是高变化度占主导,襄阳站和皇庄站高变化度的水文指标所占比例远大于其它站点,依次为53% 和75%,各站水位较蓄水前下降了1～2 m。黄家港站高/低流量脉冲出现的频率减少（变化度为-0.49和 -0.62）,且持续的时间变短（变化度为-0.87和 -0.74）。皇庄站和襄阳站流量和水位的月均值和极值较蓄水前减少,逆转次数在高RVA范围内较蓄水前增加（变化度为1.82）。四大家鱼产卵的敏感水文指标出现频率较蓄水前减少,且为中高变化度。下游河道枯水期流量和水位减小,增加了水华发生几率。     

F-RNA噬菌体及其作为水中肠道病毒指示物的研究进展

城市污水的再生利用是缓解水资源紧张、减少水污染和改善生态环境的有效途径。污水及其回用水中的肠道病毒对人体健康的风险日益受到关注。直接检测水中肠道病毒的操作复杂、安全性差、时间长、需要专门的技术和设备，因此需要寻找合适的指示生物，以实现对水中肠道病毒的及时检测和风险评价。F-RNA噬菌体是通过性菌毛感染雄性大肠杆菌的一类RNA细菌病毒，在污水中普遍存在，在大小、形态结构及对环境条件和水处理过程的抗性与肠道病毒相似，被认为是水中肠道病毒的合适的指示生物。文章介绍了F-RNA噬菌体在环境及污水中的分布、存活和去除特性、检测方法及作为水中肠道病毒指示生物的研究进展。     

Cost-Efficiency of Decaying Wood as a Surrogate for Overall Species Richness in Boreal Forests

Abstract:  Decaying wood is one of the most important elements for species richness in boreal forests. We tested how well reserve selection based on the amount and quality of decaying wood results in a representation of four ecologically different taxa (beetles, birds, wood-inhabiting fungi, and vascular plants). We also compared the cost-efficiency of the use of dead-wood indicators with comprehensive species inventory. Our database included 32 seminatural old-forest stands located in northern Finland. Decaying wood was a relatively good indicator of saproxylic species but not overall species richness. Even though dead wood did not reflect accurately overall species richness, our results indicated that the use of decaying wood as an indicator in site selection was more cost-efficient than using information from large-scale species inventories. Thus, decaying wood is a valuable surrogate for species richness, but other cost-efficient indicators that reflect the requirements of those species which are not dependent on decaying wood should be identified.     

土壤酶活性及其对土壤质量的指示研究进展

土壤中所进行的生物和生物化学过程是陆地生态系统功能的基础 ,这些过程之所以能够持续进行 ,得益于土壤中酶的作用 .酶是土壤生态系统代谢的一类重要动力 ,土壤中所进行的一切生物学和化学过程都要由酶的催化作用才能完成 .虽然单一种类的土壤酶的催化作用可能是专性的 ,但土壤中酶的来源不同 ,酶的种类繁多 .土壤中已经被鉴定出的约 6 0种酶活性表明 ,土壤酶活性是与土壤质量的很多理化指标相联系的 ,酶的催化作用对土壤中元素 (包括Ｃ、Ｎ、Ｐ、Ｓ)循环与迁移有着重要作用 .历史上 ,土壤化学和物理学属性一直被用来作为表征土壤生产力和…     

Importance of conserving large and old trees to continuity of tree-related microhabitats

Protecting structural features, such as tree-related microhabitats (TreMs), is a cost-effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Using a tree-ring-based approach and a large data set of 8038 trees, we modeled the effects of tree age, diameter, and site characteristics on TreM richness and occurrence across some of the most intact primary temperate forests in Europe, including mixed beech and spruce forests. We observed an overall increase in TreM richness on old and large trees in both forest types. The occurrence of specific TreM groups was variably related to tree age and diameter, but some TreM groups (e.g., epiphytes) had a stronger positive relationship with tree species and elevation. Although many TreM groups were positively associated with tree age and diameter, only two TreM groups in spruce stands reacted exclusively to tree age (insect galleries and exposed sapwood) without responding to diameter. Thus, the retention of trees for conservation purposes based on tree diameter appears to be a generally feasible approach with a rather low risk of underrepresentation of TreMs. Because greater tree age and diameter positively affected TreM development, placing a greater emphasis on conserving large trees and allowing them to reach older ages, for example, through the establishment of conservation reserves, would better maintain the continuity of TreM resource and associated biodiversity. However, this approach may be difficult due to the widespread intensification of forest management and global climate change.     

The development and applications of a Drought Early Warning System in Botswana*

This article describes the indicators and data sources used by the Botswana Drought Early Warning System formally established in early 1984, the main uses of the indicators in the assessment of drought conditions and the design of relief programmes are outlined. Limitations of the sources of data available are discussed, as is the feasibility of adding some possible further indicators. In conclusion, the importance of a functioning Early Warning System in a country highly susceptible to repeated droughts is stressed, in the context of die current effort to elaborate a comprehensive National Food Strategy and to establish a Regional Early Warning System for Southern Africa.