我国外来生物入侵的现状及对策

外来生物在丰富了区域生物物种的同时,也带来了一些负面影响,对生态环境、生物多样性和社会经济造成很大危害。我国外来生物入侵现象越来越严重,入侵生物种类多、来源广泛,外来生物入侵问题越来越受到重视。本文对外来生物入侵提出了一些防范措施。     

我国外来生物入侵的现状及对策

外来生物在丰富了区域生物物种的同时,也带来了一些负面影响,对生态环境、生物多样性和社会经济造成很大危害。我国外来生物入侵现象越来越严重,入侵生物种类多、来源广泛,外来生物入侵问题越来越受到重视。本文对外来生物入侵提出了一些防范措施。     

我国海域近来相继出现赤潮 国家海洋局提请高度重视海洋环保

据报道,自去年以来,我国一些海域相继出现赤潮,给海洋生物资源和生态环境造成危害。国家海洋局最近提请各有关方面重视这一问题,迅速控制赤潮发生率提高的趋势。所谓赤潮,是指海水中浮游生物爆发性增殖而形成的一种水体变色现象。由于浮游生物的过量增殖,迅速消耗了海水中的溶解氧,造成缺氧环境,生活在该海区的海洋生物遭受损害以致出现死亡。赤潮发生区的水体颜色可因浮游生物种类不同呈红、黄、绿、褐、黑色。从去年到现在,国家海洋局的海监船和海监飞机先后在舟山群岛南部海域、厦门西港的宝珠屿附近海域、长江口外海域发现赤潮。今年6至8月,仅长江口外海域就相继发生两次,有时分布范围竟长达20余海里,宽6至7海里。据介绍,70年代以前,我国有文字记载的赤潮仅发生过3次,70年代以后已发生10余次。它已成     

甲藻赤潮和水华应急处置技术的进展

近年来,我国甲藻赤潮和水华经常发生,致使生态系统进一步恶化。根据国内外有关的研究报道,进行了综合评估分析,为在不同环境条件下,相应地采取生物、物理和化学等方法应急处置甲藻赤潮和水华提供参考。     

客观看待外来物种入侵

正何为外来生物入侵?一般而言,主动引进加以培养、种植养殖,不归类为生物入侵。而不是主动引进,对本土农业、生态环境和人畜健康产生不利影响,甚至造成重大经济损失的才能称为外来生物入侵。据专家介绍,在国际自然保护联盟公布的全球100种最具威胁的外来物种中,入侵中国的就有50余种。入侵生物危害严重,给农林业生产构成了巨大的威胁。据初步估计,松材线虫等13种主要农林入侵物种每年对我国造成574亿元的直接经济损失。同时,     

赤潮的预测与控制对策

近年来,我国沿海地区越来越频繁的赤潮对水域环境与海水养殖业等造成了严重破坏。本文从赤潮发生的条件入手,分析了赤潮的预测方法,并提出了相应的对策。     

中国1998年的三大生态灾害

目前全国生态形势很严峻，一方治理，多方破坏，点上治理，面上破坏，治理赶不上破坏，呈现出生态破坏范围在扩大、程度在加剧、危害在加重的态势。1998年，我国相继发生了三次大的生态灾害，是大自然无情地报复人类违背自然规律，不合理开发利用自然资源的一年。一、赤潮第一次大的生态灾害是赤潮，发生在广东东部的绕平县和南粤县海域，从1997年Ic月持续到1998年2月份，共100多天，面积达3000平方公里。1998年3月份在珠江口及其两侧地区，即深圳大鹏湾和香港又发生了赤潮，到3月中旬，赤潮达到了高峰。4月上旬赤潮蔓延到珠海市和阳江市附…     

赤潮生物中的新毒素

日东各地不断发生赤潮,使鱼类受害。鱼类的死亡是由于赤潮生物中的双鞭毛藻类所制造出的毒素。在这类毒素中,水溶性的蛤蚌毒素类和鞭毛毒素类已为人们所知。最近又发现了与它们的结构完全不同的脂溶性毒素短杆菌A、B、C。其中,短杆菌B的结构已经确定。是11个醚环交替并列为反式。短杆菌C的结构也基本确定,与B相似,特点是含氯。     

论外来生物入侵预警机制

外来生物入侵给世界各国的生态环境、社会经济等诸方面都带来了极大危害,成为引人关注的全球性问题。如何应对和解决该问题是一个值得思考的课题。循着预防优于治理的思路,分析了构建外来生物入侵预警机制的必要性,提出了构建外来生物入侵预警机制的原则,并在此基础上架构了该预警机制体系的内容。     

外来入侵物种,敲响中国生态警钟

今天，有害外来生物正以前所未有的规模和速度，在我国繁衍扩散，由此造成的灾害日益频繁、“外来物种”一词引起了国人的广泛关注。     

GROUNDWATER DISCHARGE AND ITS IMPACT ON SURFACE WATER QUALITY IN A CHESAPEAKE BAY INLET1

ABSTRACT: Surface water, groundwater, and groundwater discharge quality surveys were conducted in Cherrystone Inlet, on Virginia's Eastern Shore. Shallow groundwater below agricultural fields had nitrate concentrations significantly higher than inlet surface waters and shallow groundwater underlying forested land. This elevated nitrate groundwater discharged to adjacent surface waters. Nearshore discharge rates of water across the sediment-water interface ranged from 0.02 to 3.69 liters·m^?2·hr^?1 during the surveys. The discharge was greatest nearshore at low tide periods, and decreased markedly with increasing distance offshore. Vertical hydraulic heads, E_h, and inorganic nitrogen flux in the sediments followed similar patterns. Nitrate was the predominant nitrogen species discharged nearshore adjacent to agricultural land use, changing to ammonium farther offshore. Sediment nitrogen fluxes were sufficient to cause observable impacts on surface water quality; nitrate concentrations were up to 20 times greater in areas of groundwater discharge than in the main stem inlet water. Based on DIN:DIP ratios, nitrogen contributions from direct groundwater discharge and tidal creek inputs appear to be of significant ecological importance. This groundwater discharge links land use activity and the quality of surface water, and therefore must be considered in selection of best management practices and water quality management strategies.     

Offshore wind power potential of the Black Sea region in Turkey

Majority of the studies on offshore wind power potential assessment is limited to the examination of the wind speed only. This study examines the offshore wind power potential of the Black Sea coastal region in Turkey based on location selection criteria including territorial waters, military areas, civil aviation, shipping routes, pipelines and underground cables, social, and environmental concerns. Wind Atlas Analysis and Application Program (WAsP) is used to do the statistical analysis of wind speed and wind direction data for 20 locations in the Black Sea coastal region. WAsP results are then elaborated based on the location selection criteria for better assessment of offshore wind power utilization. The study reveals that there are limited numbers of locations for offshore wind power generation in the Black Sea region in spite of its long coastline. Moreover, there is a high need for a zoning change for Amasra shores in order to utilize high offshore wind power potential of Amasra. Our finding suggests that location selection criteria other than wind speed should definitely be considered for better assessment of the wind power potential of a region.     

多污染物分析与评价方法在地表水评价中的应用

参照美国EPA的水中优先检测污染物以及我国优先检测污染物的名单,重点检测了有机污染物在地表水中的分布;采用多污染物分析与评价对地表水分别从人体健康影响度(AS1)和生态环境影响度(AS2)两项指标进行了评价。     

我国鲟鱼类资源及其保护与发展途径

鲟鱼类为北半球古老的大型经济鱼类，栖息于太平洋、大西洋和内陆水域，是世界著名的经济鱼类．近年来在有关科研项目的支持下，对我国境内的11种鲟鱼类资源进行了生物学、生态学等方面的一系列调查研究．本文着重论述了鲟鱼类的自然分布、经济与科研价值，分析了资源现状及其衰退原因，并提出今后资源保护与发展的8个途径．     

Assessing the Effects of Management Alternatives on Habitat Suitability in a Forested Landscape of Northeastern China

Forest management often has cumulative, long-lasting effects on wildlife habitat suitability and the effects may be impractical to evaluate using landscape-scale field experiments. To understand such effects, we linked a spatially explicit landscape disturbance and succession model (LANDIS) with habitat suitability index (HSI) models to assess the effects of management alternatives on habitat suitability in a forested landscape of northeastern China. LANDIS was applied to simulate future forest landscape changes under four management alternatives (no cutting, clearcutting, selective cutting I and II) over a 200-year horizon. The simulation outputs were linked with HSI models for three wildlife species, the red squirrel (Sciurus vulgaris), the red deer (Cervus elaphus) and the hazel grouse (Bonasa bonasia). These species are chosen because they represent numerous species that have distinct habitat requirements in our study area. We assessed their habitat suitability based on the mean HSI values, which is a measure of the average habitat quality. Our simulation results showed that no one management scenario was the best for all species and various forest management scenarios would lead to conflicting wildlife habitat outcomes. How to choose a scenario is dependent on the trade-off of economical, ecological and social goals. Our modeling effort could provide decision makers with relative comparisons among management scenarios from the perspective of biodiversity conservation. The general simulation results were expected based on our knowledge of forest management and habitat relationships of the species, which confirmed that the coupled modeling approach correctly simulated the assumed relationships between the wildlife, forest composition, age structure, and spatial configuration of habitat. However, several emergent results revealed the unexpected outcomes that a management scenario may lead to.     

世界经济掀起绿色浪潮国际环保市场充满商机

本文介绍了发达国家绿色产业发展的现状及趋势,预示绿色产业在国际环保市场的领先潮流。我国要顺应这绿色潮流,提高我国环保产业在国际市场上的竞争力。     

水生植物化感作用应急处置海洋赤潮和淡水水华

近年来,植物化感作用逐渐成为控制藻类暴发的一种新技术。根据国内外的研究成果,着重从水生植物化感作用、化感抑藻物质、应急处置藻类方法、海洋赤潮和淡水水华的应急处置及机理进行评述,并对该技术今后的发展予以展望。     

中国南方红黄壤旱地多熟制效益的系统分析

我国南方有1.58亿亩的红黄壤旱地,目前生产力水平很低。为了开发红黄壤旱地,挖掘其生产潜力,我们于1986～1989年在江西南昌进行了多熟制的定位试验。结果表明,红黄壤旱地发展多熟制可以大幅度提高土地生产力,培肥地力,达到生态效益、经济效益和社会效益同步增长。同时,为了全面、合理地评价耕作制度,文章采用了综合评判的方法,对本试验的6个多熟制的效益进行了系统分析,对其优劣作了较客观的评价,但这一分析方法还有待进一步完善。     

Microbiological Monitoring of Marine Recreational Waters in Southern California

An inventory was conducted to assess the number, type, spatial distribution, and costs of microbiological monitoring programs in southern California marine waters from Point Conception to the US/Mexico International Border. The location of each sampling site was determined using global positioning system (GPS), and estimates of geographic coverage were determined using geographic information system (GIS) techniques. Twenty-one programs conducted 87,007 tests annually at 576 sites in the study area. The largest number of sites was sampled in Orange County, whereas the largest number of analyses was performed in Los Angeles County because monitoring programs in this area focused on daily monitoring. Fifteen of the 21 programs were managed by National Pollutant Discharge Elimination System (NPDES) permitted sewage effluent dischargers who sampled both offshore and shoreline waters and typically tested for three indicator bacteria (total coliform, fecal coliform, and enterococcus). Their combined efforts comprised 82% of all of the microbiological indicator analyses conducted on an annual basis. Five of the remaining monitoring organizations were public health agencies, which typically focus their efforts on testing only total coliforms. Laboratory methodology also varied considerably, with NPDES permittees predominantly utilizing membrane filtration while public health agencies generally used multiple tube fermentation or premanufactured test kits. Nearly three quarters of all the effort expended in southern California occurred along the shoreline as opposed to offshore locations. Two thirds of this shoreline effort was focused on high-use sandy beaches and in proximity to perennial freshwater outlets (storm drains and creeks). Most sampling occurred at a set of fixed sites that were revisited frequently, but only represented about 7% of the total shoreline. We estimated that roughly $3 million is spent annually on monitoring bathing water quality in southern California, exceeding that spent in any other part of the country.