城市污泥不同处理处置方式的成本和效益分析--以北京市为例

以北京市为例,估算不同电价及运输距离下填埋、焚烧及堆肥等方式的城市污泥处理处置成本,在此基础上讨论各种处理处置方案的前景,展望北京市污泥处理处置出路。污泥填埋在一定时期内还将是主要处理处置方式,但所占比例将逐渐下降;堆肥是经济上较为可行的处理处置方式,适合大力推广;随着经济实力与技术水平提高,焚烧法可以适用于个别特殊地点。同时,分析了政府补贴对污泥处理处置效益的影响。     

乙酰辅酶A羧化酶:脂肪酸代谢的关键酶及其基因克隆研究进展

乙酰辅酶A羧化酶(Acetyl-CoA carboxylase,ACC)在脂肪酸合成和分解代谢中发挥着重要作用.系统介绍了该酶的结构与分类、生物学作用与应用、抑制剂的类型与作用机理以及基因克隆4个方面的进展.ACC在大多数原核生物中为多亚基型酶,而在大多数真核生物中为多功能型单亚基酶,在天蓝色链霉菌和古菌勤奋金属球菌中为另外两种特殊类型;但都具备3个关键的功能域,即生物素羧化酶(BC)、生物素羧基载体蛋白(BCCP)和羧基转移酶(CT).CT功能域作为潜在的靶标广泛应用于植物除草剂的筛选和哺乳动物肥胖、糖尿病等代谢疾病的药物设计中.ACC基因也成为转基因油料作物和生物柴油研究中重要的靶标基因.研究表明,植物质体中的β-CT亚基是多亚基型ACC的限制因子,而BCCP是脂肪酸合成的负调控因子.油脂的合成代谢十分复杂,且存在反馈抑制机制,因此克隆和表达ACC基因可以提高宿主中ACC的活性,但不一定能显著促进脂肪酸的积累.图2参52     

The possible origin of Zostera noltii in the Canary Islands and guidelines for restoration

Seagrasses and their habitat are declining worldwide. Zostera noltii in the Canary Islands has been drastically reduced, mainly by anthropogenic disturbance, to three small surviving patches in a single harbor in Lanzarote. A previous genetic study, using neutral microsatellite markers, revealed that these patches consist of a single clonal individual. Here, an assignment test, using microsatellite data, was used to locate the most likely population of origin from a set of possible donor populations. Our results show that the Moulay Bousselham population in northern Morocco is assigned as the most likely population of origin (88%), although the probability of being at one generation time distance is low (2.7%). This result, however, allows locating the most closely related stands that may be the most successful donor populations for future restoration based on shoot or seed transplantation.     

Global conservation status of sponges

Sponges are important for maintaining ecosystem function and integrity of marine and freshwater benthic communities worldwide. Despite this, there has been no assessment of their current global conservation status. We assessed their status, accounting for the distribution of research effort; patterns of temporal variation in sponge populations and assemblages; the number of sponges on threatened species lists; and the impact of environmental pressures. Sponge research effort has been variable; marine sponges in the northeastern Atlantic and Mediterranean and freshwater sponges in Europe and North America have received the most attention. Although sponge abundance has increased in some locations since 1990, these were typically on coral reefs, in response to declines in other benthic organisms, and restricted to a few species. Few data were available on temporal trends in freshwater sponge abundance. Despite over 8500 described sponge species, only 20 are on threatened species lists, and all are marine species from the northeastern Atlantic and Mediterranean. Of the 202 studies identified, the effects of temperature, suspended sediment, substratum loss, and microbial pathogens have been studied the most intensively for marine sponges, although responses appear to be variable. There were 20 studies examining environmental impacts on freshwater sponges, and most of these were on temperature and heavy metal contamination. We found that most sponges do not appear to be threatened globally. However, little information is available for most species and more data are needed on the impacts of anthropogenic‐related pressures. This is a critical information gap in understanding sponge conservation status. Estado Global de la Conservación de Esponjas     

云南地区种子植物区系属的多度及区系过渡性的空间分布格局

植物区系地理分布格局的研究有助于更好地理解植物区系的起源、迁移和分化。研究利用覆盖云南地区全境的植物区系分布信息,探讨了云南地区植物区系属的多度及区系过渡性的地理分布格局。结果表明,所有热带区系属的多度均随着纬度升高呈递减趋势;大多数温带区系属的多度随着纬度的升高呈递增趋势。中亚分布（T13）属的多度的高值主要出现在滇西北地区,尤其是在金沙江、澜沧江和怒江的上游地区,但在其它地区十分少见。地中海、西亚至中亚分布（T12）属的多度的高值也出现在滇西北地区,但在其它地区无明显空间分布规律;中国特有分布（T15）属在滇西北地区最为丰富,其次是滇东南地区,大致以“田中线”为界,界线以西地区的中国植物特有属的多度明显低于界线以东地区。从南到北,植物区系过渡性基本上呈单调递增格局,这一格局的形成可能与区系成分的迁移和地形格局有关。大理州以南的低海拔地区,热带区系成分占据主导地位,并占据了云南大部分的土地面积,这在一定程度上证实了云南地区总体上是一个“热带山原”的假说。本研究与其它研究的不同可能源于与源数据和取样尺度的差异。     

Determining groundwater quality using indices and multivariate statistical techniques: a study of Tosham block,Haryana, India

Environmental Geochemistry and Health - Water is the most important component for human survival and often the most misused one. The present study deals with the assessment of groundwater quality...     

Influence of wave exposure on South African mussel beds and their associated infaunal communities

This study investigates effects of wave exposure on beds of the mussel Mytilus galloprovincialis and the infaunal communities associated with them. Nine sites of varying wave exposure were sampled near Groenrivier, on the west coast of South Africa. Wave exposure was measured using a Palumbi device, and exposure ranged from 7.17×10³ to 18.49×10³ N m^–2. Percentage mussel cover at each site was measured using 50×50 cm quadrats, and three 10×10 cm samples were removed from the mussel beds in the mid-intertidal zones of each site for examination of infauna. Percentage mussel cover, mean mussel length, mussel biomass and mussel bed depth all peaked at intermediate exposures, declining towards both the most sheltered and most exposed sites. Infaunal species diversity and richness both showed the reverse trend, peaking at the most sheltered and most exposed sites, and declining at intermediate exposures. Neither infaunal abundance, nor biomass, was significantly correlated to wave exposure, although abundance was highest at sheltered sites and biomass greatest at the most exposed site, which was dominated by limpets and large robust polychaetes.Communicated by J.P. Thorpe, Port Erin     

潜叶虫潜道图像分析

为通过潜叶虫潜食叶片所留下的潜道分析其分类、行为和生态,应用Getdata图形数字化软件和R语言,提取线形潜道的数字化图像,并获得各种图像形状参数,如平均转角、转角集中度、分维D、直线度ST、蜿蜒度SN等.结果发现:大多数潜道的平均转角较小(不超过±25.0°),转角集中度较高(>0.600),说明潜食方向大多保持为前进方向;多数潜道的ST在0.010到0.300之间,数值极小,而SN一般都超过0.600,表明多数潜叶昆虫潜道的蜿蜒程度非常大;米楮上两种潜叶蛾的潜道形状参数如D和ST存在显著差异.     

The effects of exposure to zinc and cadmium separately and jointly on the free amino acid pool of Gammarus pulex (L.)

Effects of the heavy metals zinc and cadmium on the free amino acid (FAA) pool of Gammarus pulex were studied at different metal concentrations and combinations as well as different exposure times. The dominant effect of these two metals was the reduction of most free amino acids and the whole FAA pool, except in the 10‐day low zinc and cadmium concentration exposures which resulted in a rise of free amino acid pool.

Among the free amino acids, the most sensitive to zinc exposure, were alanine, glutamic acid, arginine, and taurine; valine, leucine, asparagine, and isoleucine were among the most sensitive to cadmium. No predictable changes of individual free amino acids were shown in the mixed metals exposures. Elevation of taurine concentration was constant in seven of the eight treatments, it is suggested that this elevation may be related to the hepatopancreatic damage observed and induced synthesis of metallothioneins.     

Importance of Reserve Size and Landscape Context to Urban Bird Conservation

Abstract:  We tested whether reserve size, landscape surrounding the reserve, and their interaction affect forest songbirds in the metropolitan area of Seattle, Washington (U.S.A.), by studying 29 reserves of varying size (small, medium, large) and surrounding urbanization intensity (urban, suburban, exurban). Larger reserves contained richer and less even bird communities than smaller reserves. These size effects disappeared when we removed the positive correlation of shrub diversity with reserve size, suggesting that greater habitat diversity in large reserves supported additional species, some of which were rare. Standardizing the number of individuals detected among all reserve size classes reversed the effect of size on richness in exurban landscapes and reduced the magnitude of the effect in suburban or urban landscapes. The latter change suggested that richness increased with reserve size in most landscapes because larger areas also supported larger samples from the regional bird species pool. Most bird species associated with native forest habitat (native forest species) and with human activity (synanthropic species) were present in reserves larger than 42 ha and surrounded by >40% urban land cover, respectively. Thus, we recommend these thresholds as means for conserving the composition of native bird communities in this mostly forested region. Native forest species were least abundant and synanthropic species most abundant in urban landscapes, where exotic ground and shrub vegetation was most common. Therefore, control of exotic vegetation may benefit native songbird populations. Bird nests in shrubs were most dense in medium (suburban) and large reserves (urban) and tended to be most successful in medium (suburban) and large reserves (exurban), potentially supplying another mechanism by which reserve size increased retention of native forest species.     

Characterizing temperate rocky shores from the perspective of an early juvenile snail: the main threats to survival of newly hatched Nucella emarginata

Mortality factors most likely to constitute substantial selective pressures for early juvenile gastropods on temperate rocky shores were identified by examining the vulnerability of hatchlings of an intertidal snail, Nucella emarginata, to heat stress, desiccation, and predation in 1992 and 1993. The highest temperature of substrata measured at tidal heights colonized by N. emarginata in Barkley Sound, British Columbia, Canada, was 28.5°C. This temperature was not lethal to hatchlings in laboratory tests. In laboratory and field desiccation experiments, all hatchlings died within 6 h of emersion. Early juveniles could not survive direct exposure to even moderate drying conditions for the duration of a low tide. Hence, intertidal microhabitats which dry up even for short periods during low tides would prove lethal. Of 45 intertidal animal species to which hatchlings were exposed in the laboratory, small decapod crustaceans were the only organisms to cause substantial hatchling mortality. Of these, Pagurus hirsutiusculus and Hemigrapsus nudus were by far the most abundant in the field, and are probably the only important predators of early juvenile N. emarginata at most sites. Total predator densities in the field were as high as 438 individuals m^–2, suggesting that predation pressure may be intense. Desiccation and predation by decapod crustanceans appear to be the most significant threats to early juvenile N. emarginata. These factors commonly occur on most temperate rocky shores and undoubtedly constitute major selective agent influencing population parameters and shaping life-history strategies and early juvenile traits of intertidal invertebrates.     

有机酸对珠江三角洲水稻土镉解吸行为的影响

用批平衡实验方法,研究了3种有机酸及其两两混合酸在一系列pH值梯度下(pH3~7)对珠江三角洲沉积型水稻土镉(Cd)解吸的影响.结果表明,只有柠檬酸及含柠檬酸的混合酸在较低酸度区(pH>5)可以显著促进Cd的解吸,这一效应与浓度成正相关,而苹果酸、草酸及二者的混合酸在所试验酸度范围均促进了Cd吸附,特别是草酸,促进作用随浓度的升高而增强.在较低pH区(pH<5),苹果酸最有利于Cd解吸,在高pH区(pH≥5),柠檬酸最有利于Cd解吸,草酸的Cd解吸能力最低.混合有机酸交互作用不显著,对Cd解吸的影响约等于各个单独酸的作用之和,但在一些酸度条件下,可存在颉颃作用.图3表2参22     

Aspects of the community ecology of deep-sea,benthopelagic plankton,with special attention to gymnopleid copepods

Benthopelagic plankton was collected 10 to 100 m above the bottom of the deep sea (1100 to 3200 m) with an opening-closing net. Five samples were taken from the San Diego Trough, 2 from the eastern tropical Pacific and 2 from the northeast Atlantic. Roughly 80% of the individual organisms collected were copepods; the next most abundant groups were usually isopods, ostracods, and chaetognaths. Within the depth range studied, absolute abundances of most animal groups decreased with depth, but relative abundances (%) did not change. Of over 100 species of adult gymnopleid copepods collected, a few species were abundant, but most were rare. Copepod exoskeletons were more abundant than living copepods. For the gymnopleids, similarities among the 3 geographical regions were strong at the family and genus level but weak at the species level. Species that were widely distributed horizontally tended to occupy different positions (in terms of rank order of abundance) in each community. Gut content analysis indicated that the most abundant gymnopleids were generalized particle feeders. However, size-frequency distributions provided indirect evidence for niche separation. The deep-sea benthopelagic plankton was divisible into a truly planktonic component and a bottom-associated component. Abundances of some copepods changed relative to distance off the bottom. Several copepods and other animals, previously described as epibenthic or bottom-associated, were collected more that 10 m above the bottom and thus appeared to move freely between the bottom and lower water column.     

Hazard and vulnerability evaluation of water distribution system in cases of contamination intrusion accidents

In this paper, it proposed an index system for hazard and vulnerability evaluations of water distribution networks, based on the simulation of contamination events caused by pollutant injections at different junctions. It attempted to answer the following two questions in the case of contamination events: 1) Which are the most hazardous junctions? 2) Which are the most vulnerable junctions? With EPANET toolkit, it simulated the propagation of the contaminant, and calculated the peak concentration of the contaminant and mass delivered at different nodes. According to types of consumers, different weights were assigned to the consumer nodes for assessing the influence of the contaminant on the consumers. Using the method proposed herein, both the hazard index and vulnerability index were calculated for each node in the pipe network. The presented method was therefore applied to the water network of the city of Zhenjiang, which contains two water plants, two booster pump stations with storage tanks. In conclusion, the response time, the relationships between the peak concentration of contaminant and the total absorption are the most important factors in hazard and vulnerability evaluation of the water distribution network.     

Fractionation analysis of some heavy metals in sediments of the north-western part of the Red Sea,Egypt

Sequential extraction was used to study operationally determined chemical forms (exchangeable, carbonate, reducible metal, oxidisable metal and the residual fractions) of the metals Cd, Cu, Zn and Pb in sediments from 12 sample sites collected from the north-western part of the Red Sea, where improper recreational facilities have resulted in diverse impacts on the coastal environments fronting some of the recreation projects. The results showed that the average percentage of each phase was different among metal types; the residual binding fraction was the most important phase for binding Zn and to a lesser degree Cu. The reducible fraction was the second most important phase for Zn and Cu. For Pb, the fractions bounded to the residual fractions and the reducible phases are equal and exhibited the highest percentages. By contrast, the carbonate fraction was predominant for Cd. The percentages of Cd, Cu, Zn and Pb associated with the carbonate and exchangeable fractions, which are potentially the most harmful to the environment, were calculated and assessed at different sampling sites of the studied sediments. According to the Risk Assessment Code (RAC), the results reveal that Cd is the only metal that poses a high risk to the environment.     

基于气象灾害的青岛市域生态风险评价

根据美国环保局（USEPA）的生态风险评价框架和相对风险模型（Relative Risk Model,RRM）,对青岛市域县级行政区的干旱、洪涝、大风和冰雹4种气象灾害进行了生态风险评价。评价结果表明,研究区内干旱生态风险最为严重,洪涝其次;耕地承受的风险最高,城镇和居民地其次;胶州的生态风险最大,青岛市区其次。而且胶州的干旱灾害、市区的大风灾害、平度的冰雹灾害以及胶南的草地成灾比较突出,成为风险分区的依据。最后,不确定性分析表明RRM不确定性的模拟值与计算值接近,验证了RRM在县级尺度上的适用性;敏感性分析说明相对风险值对干旱等级4最为敏感,且对生境分级敏感程度高于风险源分级。此外,利用生态系统生态服务功能的损失率确定暴露系数,降低了确定暴露系数带来的随机性。同时,生境变化需要进一步考虑以明确生态风险在时间尺度上的变化特点。     

Effective conservation planning of Iberian amphibians based on a regionalization of climate-driven range shifts

Amphibians are severely affected by climate change, particularly in regions where droughts prevail and water availability is scarce. The extirpation of amphibians triggers cascading effects that disrupt the trophic structure of food webs and ecosystems. Dedicated assessments of the spatial adaptive potential of amphibian species under climate change are, therefore, essential to provide guidelines for their effective conservation. I used predictions about the location of suitable climates for 27 amphibian species in the Iberian Peninsula from a baseline period to 2080 to typify shifting species’ ranges. The time at which these range types are expected to be functionally important for the adaptation of a species was used to identify full or partial refugia; areas most likely to be the home of populations moving into new climatically suitable grounds; areas most likely to receive populations after climate adaptive dispersal; and climatically unsuitable areas near suitable areas. I implemented an area prioritization protocol for each species to obtain a cohesive set of areas that would provide maximum adaptability and where management interventions should be prioritized. A connectivity assessment pinpointed where facilitative strategies would be most effective. Each of the 27 species had distinct spatial requirements but, common to all species, a bottleneck effect was predicted by 2050 because source areas for subsequent dispersal were small in extent. Three species emerged as difficult to maintain up to 2080. The Iberian northwest was predicted to capture adaptive range for most species. My study offers analytical guidelines for managers and decision makers to undertake systematic assessments on where and when to intervene to maximize the persistence of amphibian species and the functionality of the ecosystems that depend on them.     

An evaluation of procedures for the digestion of soils and vegetation from areas with metalliferous pollution

Various digestion or extraction processes are available for the determination of trace metals in environmental samples using diverse analytical techniques. Our research examines the most efficient and reproducible methods of digestion utilising readily available laboratory equipment, reagents and instrumentation. Extraction procedures reported in over 80 recent research works were considered and the most common methods were critically evaluated. Thus nitric acid, nitric acid/perchloric acid, aqua regia, nitric acid/hydrogen peroxide and microwave-assisted methods were investigated using soil and leaf samples collected adjacent to three old metalliferous workings. Analysis was carried out using Flame Atomic Absorption Spectrometry and the results were evaluated. Differences in efficiency of extraction relative to specific metals and different substrates are highlighted and recommendations made for a digestion procedure suitable for environmental samples. Aqua regia produced the most accurate, efficient and reproducible results; we consider methods of improving both of these factors and sample preparation. Our recommended methodology has applications in environmental surveys, environmental geology, environmental toxicology, geochemistry and provides a means of obtaining meaningful and reliable results for the determination of metals present in soils, minerals and vegetation.     

Impacts of hunting on tropical forests in Southeast Asia

Although deforestation and forest degradation have long been considered the most significant threats to tropical biodiversity, across Southeast Asia (Northeast India, Indochina, Sundaland, Philippines) substantial areas of natural habitat have few wild animals (>1 kg), bar a few hunting‐tolerant species. To document hunting impacts on vertebrate populations regionally, we conducted an extensive literature review, including papers in local journals and reports of governmental and nongovernmental agencies. Evidence from multiple sites indicated animal populations declined precipitously across the region since approximately 1980, and many species are now extirpated from substantial portions of their former ranges. Hunting is by far the greatest immediate threat to the survival of most of the region's endangered vertebrates. Causes of recent overhunting include improved access to forests and markets, improved hunting technology, and escalating demand for wild meat, wildlife‐derived medicinal products, and wild animals as pets. Although hunters often take common species, such as pigs or rats, for their own consumption, they take rarer species opportunistically and sell surplus meat and commercially valuable products. There is also widespread targeted hunting of high‐value species. Consequently, as currently practiced, hunting cannot be considered sustainable anywhere in the region, and in most places enforcement of protected‐area and protected‐species legislation is weak. The international community's focus on cross‐border trade fails to address overexploitation of wildlife because hunting and the sale of wild meat is largely a local issue and most of the harvest is consumed in villages, rural towns, and nearby cities. In addition to improved enforcement, efforts to engage hunters and manage wildlife populations through sustainable hunting practices are urgently needed. Unless there is a step change in efforts to reduce wildlife exploitation to sustainable levels, the region will likely lose most of its iconic species, and many others besides, within the next few years.     

Spatio-temporal patterns of juvenile marine turtle occurrence in waters of the European continental shelf

We present data spanning approximately 100 years regarding the spatial and temporal occurrence of marine turtle sightings and strandings in the northeast Atlantic from two public recording schemes and demonstrate potential signals of changing population status. Records of loggerhead (n = 317) and Kemp’s ridley (n = 44) turtles occurring on the European continental shelf were most prevalent during the autumn and winter, when waters were coolest. In contrast, endothermic leatherback turtles (n = 1,668) were most common during the summer. Analysis of the spatial distribution of hard-shell marine turtle sightings and strandings highlights a pattern of decreasing records with increasing latitude. The spatial distribution of sighting and stranding records indicates that arrival in waters of the European continental shelf is most likely driven by North Atlantic current systems. Future patterns of spatial-temporal distribution, gathered from the periphery of juvenile marine turtles habitat range, may allow for a broader assessment of the future impacts of global climate change on species range and population size.