横沙岛潮滩沉积物中重金属的空间分布与累积

长期以来,长江流域的工农业及城市生活排污一直没有得到有效的控制,这必将对下游河口地区的生态环境造成直接或潜在的威胁。因此,针对横沙岛目前的潮滩环境进行研究,并就潮滩质量和发展趋势进行评价非常必要。通过对横沙岛潮滩表层沉积物中重金属元素空间分布与累积的统计学分析,得知横沙岛潮滩环境总体比较清洁,但多年来受城市工业废水和生活污水排放,以及城市汽车尾气和工业粉尘干湿沉降的影响,局部地区表现出较严峻的污染形势,Cu、Zn、Cr、Pb的最高浓度分别达到背景值的2.34、4.24、2.74和1.63倍。通过对潮滩表层沉积物粒度和有机质含量的分析,指出水动力条件、潮滩生物活化作用是影响重金属空间分布和累积的主要因素。     

The role of the Alliance of Small Island States (AOSIS) in the negotiation of the United Nations Framework Convention on Climate Change (UNFCCC)

The United Nations Framework Convention on Climate Change (UNFCCC), which was signed by some 153 countries at the Earth Summit in Rio de Janeiro, Brazil in 1992, represented a singular triumph for the geographically dispersed group of island states and low-lying coastal developing countries, located in the Pacific, Atlantic and Indian Oceans, as well as in the Caribbean, South China and Mediterranean Seas, and known as the Alliance of Small Island States (AOSIS). This article focuses on the goals of AOSIS during the negotiations leading up to the adoption of the UNFCCC. For the first time in the history of the United Nations, a group of small states, hitherto relegated to the sidelines, was able to develop a specific negotiating agenda addressing areas which are of overriding concern to them and succeeded in having those concerns incorporated in a legally binding Convention of historic importance. As this article reveals, AOSIS set itself 12 negotiating goals during the negotiating rounds leading up to the UNFCCC, and 10 of these 12 goals were realized. Nevertheless, AOSIS, whose member states are most vulnerable to the possible adverse effects of climate change, was particularly concerned about those provisions of the UNFCCC that were either watered-down significantly, made largely meaningless or excluded altogether. These include: the absence of definite targets or specific timetables for the significant reduction of carbon dioxide by the industrialized countries of the North; the lack of permanent and clear financing arrangements in particular the lack of definitive financial provisions for adaptive response measures to the adverse impacts of climate change such as sea-level rise; and the absence of a specific provision for the implementation of coastal zone management schemes for those countries most vulnerable to sea-level rise. As the UNFCCC moves into the implementation phase, AOSIS should and must build on its past success. To do so, it will need to develop clearly defined initiatives aimed at strengthening the commitments for financing and insurance, and to seek inclusion of a provision to develop and finance coastal zone management schemes for the most vulnerable small states. While the article covers the AOSIS negotiating period up to and including the Earth Summit in June 1992, we nevertheless postulate some possible objectives which the AOSIS group might wish to consider in what is sure to be an intensive post-Earth Summit phase of the UNFCCC, leading up to the first Conference of the Parties of that Convention.     

2019年8月海南岛三亚地震的控震断裂及未来地震危险性分析

2019年8月20日,海南省三亚市天涯区连续发生两次有感地震.为研究本次地震的控震断裂及琼南地区未来的地震危险性,综合分析了琼南地区历史地震活动特征和主要断裂的构造活动特征.结果表明:近EW向九所-水断裂在琼南地区起主要控震作用,沿断裂带小型地震频繁而密集发生.震中周边的NW向乐东-田独断裂较其他方向断裂活动时代最新,...     

Genetically informed captive breeding of hybrids of an extinct species of Galapagos tortoise

Hybridization poses a major challenge for species conservation because it threatens both genetic integrity and adaptive potential. Yet, hybridization can occasionally offer unprecedented opportunity for species recovery if the genome of an extinct taxon is present among living hybrids such that selective breeding could recapture it. We explored the design elements for establishing a captive-breeding program for Galapagos tortoises (Chelonoidis spp.) built around individuals with admixed ancestry involving an extinct species. The target individuals were hybrids between the extinct species from Floreana Island, C. niger, and an extant species, C. becki, which were recently found in the endemic range of C. becki, from Wolf Volcano on Isabela Island. We combined genotypic data from 35 tortoises with high ancestry from C. niger with forward-in-time simulations to explore captive breeding strategies that maximized overall genetic diversity and ancestry from C. niger while accommodating resource constraints, species biology, and the urgency to return tortoises to Floreana Island for facilitating ecosystem restoration. Overall genetic diversity was maximized when in the simulation tortoises were organized in relatively small breeding groups. Substantial amounts of the C. niger genome were captured despite limited resources available for selectively breeding tortoises in captivity. Genetic diversity was maximized when captive-bred offspring were released to the wild rather than being used as additional breeders. Our results provide genetic-based and practical guidance on the inclusion of hybrids with genomic representation from extinct taxa into species restoration programs and informs the ongoing debate on the value of hybrids in biodiversity conservation.     

崇明北滩鱼类群落生物多样性初探

对1994~2003年崇明北滩鱼类群落进行了研究,用多种指数对该群落生物多样性进行了描述。该群落共有鱼类33种,分别隶属于10目19科29属。生态类型为江海洄游鱼类、河口鱼类和海水鱼类,小型鱼类占绝对优势。群落优势种为凤鲚、棘头梅童鱼和小黄鱼。多样性特征值年间平均指标为：Margalef指数0.84,Wilhm改进指数1.51,Pielou指数0.63,McNaughton指数0.67。崇明北滩鱼类群落经济鱼类趋于小型化,生物多样性呈下降趋势。水环境污染及工程建设的不利影响应得到重视,无选择性网具的使用应受到严格控制。     

Phenotypic Effects of Cattle Mitochondrial DNA in American Bison

Hybridization between endangered species and more common species is a significant problem in conservation biology because it may result in extinction or loss of adaptation. The historical reduction in abundance and geographic distribution of the American plains bison (Bison bison bison) and their recovery over the last 125 years is well documented. However, introgression from domestic cattle (Bos taurus) into the few remaining bison populations that existed in the late 1800s has now been identified in many modern bison herds. We examined the phenotypic effect of this ancestry by comparing weight and height of bison with cattle or bison mitochondrial DNA (mtDNA) from Santa Catalina Island, California (U.S.A.), a nutritionally stressful environment for bison, and of a group of age‐matched feedlot bison males in Montana, a nutritionally rich environment. The environmental and nutritional differences between these 2 bison populations were very different and demonstrated the phenotypic effect of domestic cattle mtDNA in bison over a broad range of conditions. For example, the average weight of feedlot males that were 2 years of age was 2.54 times greater than that of males from Santa Catalina Island. In both environments, bison with cattle mtDNA had lower weight compared with bison with bison mtDNA, and on Santa Catalina Island, the height of bison with cattle mtDNA was lower than the height of bison with bison mtDNA. These data support the hypothesis that body size is smaller and height is lower in bison with domestic cattle mtDNA and that genomic integrity is important for the conservation of the American plains bison. Efectos Fenotípicos del ADN Mitocondrial de Ganado en el Bisonte Americano     

高位池养虾对土壤微生物脂肪酸和土壤酶活及其表征的土壤质量的影响

为评价高位池养虾对土壤质量的影响,通过脂肪酸分析和土壤酶活测定比较海南岛白马井镇高位池土壤与原始土壤微生物群落结构与活性的变化.结果显示,高位池土壤的pH值和盐分含量显著升高,有机质和总N显著下降(P<0.05).脂肪酸分析表明,高位池土壤中细菌、真菌、放线菌和微生物总量都显著下降(P<0.05),尤其真菌急剧下降(P<0.05),放线菌未检测到.土壤脱氢酶、脲酶和酸性磷酸酶活性在高位池土壤中也显著下降(P<0.05).总之,微生物群落结构显著变化,微生物生物量和活性在高位池土壤中都显著下降,表明长期的高位池养虾导致了土壤质量的下降.     

南长山岛不同土地利用方式下的土壤有机碳密度

土壤有机碳库是陆地生态系统中重要的碳库之一,以往对海岛生态系统土壤有机碳储量估算及其影响因素的研究较少.因此,本研究在南长山岛实测了不同土地利用方式下表层土壤的有机碳密度,比较了相互之间的差别,分析了与土壤理化性质的相关性.结果表明,南长山岛不同土地利用方式土壤有机碳密度差异显著(p0.01),表现为:针阔混交林刺槐黑松侧柏农田水库沿岸草地果园;森林土壤有机碳密度高于其他类型土壤.森林土壤有机碳密度与坡度(r=-0.459,p=0.085)、海拔相关性不显著.在土壤理化性质中,土壤全氮(r=0.763,p0.01)、有机质(r=0.833,p0.01)含量与森林土壤有机碳密度呈显著正相关.     

海南岛地区大气输送和扩散特征的数值模拟

采用中尺度气象模式WRF及风场诊断模式CALMET,结合轨迹分析和拉格朗日随机游走模拟方法,分析了海南岛地区低层大气中尺度水平输送和扩散特性,并计算了各季平均大气扩散模态.结果表明,该区域大气污染物的扩散和输送主要受到大尺度背景环流、海陆风等局地环流及地形绕流等的影响.海陆风局地环流是沿海城市源排放的大气污染物向海南本岛输送和扩散的主要机制.北部城市海口的大气扩散对岛内影响最大,冬季平均影响范围可覆盖西北半部;春、秋季主要影响西北和北部区域;夏季对本岛的影响仅限于北部沿岸.南部城市三亚的大气扩散对岛内影响较小,秋季向西南海面的扩散对本岛几乎没有影响;冬、春季对三亚以西沿岸的影响有所增加;夏季扩散影响全面指向岛内,并因地形的作用而东、西向大角度扩展,影响海岛南部的大部分沿岸地区.西北部昌江的平均输送扩散方向与当地海岸线的走向基本一致,污染影响不易深入到岛内.其中,秋季扩散影响以偏西南方向为主,仅对昌江西南部分海岸有少量影响;冬、春季扩散形态类似但影响范围扩大到以东方市为代表的低山盆地地带;海岛西北部大部分沿海地带可受到昌江夏季扩散的影响,但平均扩散方向指向东北偏北的海面.     

崇明岛土壤中MCCPs的污染水平、组成与来源研究

用GC-ECNI-MS测定了崇明岛土壤中24种中链氯化石蜡(MCCPs)同类物组的含量.目的是了解该地区土壤中MCCPs的污染水平、空间分布、组成特征和来源.结果表明MCCPs在崇明岛土壤中普遍存在,浓度范围为2.56~96.3 ng·g-1,中值为7.32 ng·g-1.聚类分析将所有样品分为两类.大多数土壤样品MCCPs以C14-MCCPs和C15-MCCPs为主要碳同类物组,分别占29.8%和28.9%;Cl5-MCCPs和Cl6-MCCPs为主要氯同类物组,分别占29.9%和23.3%;个别样品中,C14-MCCPs是主要碳同类物组,占68.5%,与CP-52的组成相似.大气沉降和土壤-大气交换可能是崇明岛土壤中MCCPs主要来源,个别点可能受到污水处理厂污泥或其他不明污染源的污染.MCCPs与TOC之间没有显著统计相关性.因子分析表明4种MCCPs的碳同类物组具有相似的来源.与国内外其它研究相比,崇明岛土壤中MCCPs处于较低水平.