“一带一路”倡议下跨境流域生态补偿——国际经验与中国对策

跨境流域生态补偿机制的构建,是实现"一带一路"倡议目标的重要基础,有助于化解资源冲突、协调区域发展、增进利益协同,进而增强政治互信,加快经济融合,提升文化包容,推进命运共同体构建。本文基于对西方国家跨境流域生态补偿研究与实践的梳理,总结归纳出西方跨境流域生态补偿中强调流域生态系统分析、注重不同付费原则相互配搭、重视双/多边协商、建立多层次综合管理体系等经验。在此基础上,针对现阶段中国跨境流域生态补偿所面临的挑战,提出加强跨境协商合作平台建设、重视对跨境流域生态系统研究以及构建多层次协同管理体系等应对措施。     

海河流域水质变化与水量的关系研究

采用曼-肯德尔和森方法,对海河流域省界断面水质达标比例和主要指标的超标比例及降雨量进行分析,探讨水质的演变特征及与降雨量的关系.结果表明:近10年非汛期达标比例和全年期COD超标比例呈现显著的变化趋势.氨氮的断面超标比例较高.汛期水质达标比例与汛期降雨量存在显著负相关,汛期降雨量增加降低了水质达标比例.DO、高锰酸盐指数、BOD和氨氮的超标比例年内变化存在差异,其主要与指标自身特性、气温以及与水文循环有关.     

新中国成立至改革开放前我国应对海洋灾害的实践及启示

梳理和总结新中国初期我国应对海洋灾害的实践,有助于我们了解海洋灾害的应对措施并为当今提供借鉴。通过对我国海洋灾害史料的分析和总结,得知从新中国成立至改革开放前这一时期内,"防重于救"是我国应对海洋灾害的的主要指导思想,在海洋灾害预测预警、建设防护性工程、群众自救和政府辅以必要救济等方面发挥了重要作用,并为之后我国应对海洋灾害打下了一定基础。     

洞庭湖表层沉积物重金属生态风险及其变化趋势研究

尽管针对洞庭湖沉积物中重金属的研究工作较多,但是针对其生态风险及其变化趋势的研究工作比较少见。基于2012年2月和2013年4月对洞庭湖9个具有代表性监测点位的采样分析以及相关监测历史资料的收集,采用Hakanson生态危害指数法,研究了洞庭湖表层沉积物中重金属的生态风险及其变化趋势。结果表明,洞庭湖表层沉积物中Cd、Hg、As、Cu和Pb的含量分别为0.60~20.7 mg·kg-1、0.090~0.640 mg·kg-1、10.4~83.7 mg·kg-1、17.9~70.9 mg·kg-1和16.9~95.8 mg·kg-1,其大小顺序为PbCuAsCdHg。洞庭湖表层沉积物中重金属单因子生态风险程度顺序为CdHgAsPbCu,Cd和Hg为主要重金属风险污染物,其中Cd为首要污染物;全湖RI值在117.10~589.80之间,平均289.99,在空间分布上,表现为南洞庭湖区西洞庭湖区东洞庭湖区;根据Hakanson提出的分级标准,南洞庭湖区Cd具有极高的生态风险,全湖生态风险程度为中。初步分析结果表明,30年来,除Hg外,其它重金属生态风险均有一定上升,其中以Cd的上升趋势较明显,全湖重金属生态风险程度由低生态风险上升到中生态风险,提高了一个等级。因此,洞庭湖流域重金属污染治理应以湘江和资水的Cd为重点。     

Response of successive three generations of cotton bollworm, Helicoverpa armigera (Hübner), fed on cotton bolls under elevated CO2

The growth, development and consumption of successive three generations of cotton bollworm, Helicoverpa armigera （Htibner）, fed on cotton bolls grown under elevated CO2 （double-ambient vs. ambient） in open-top chambers were examined. Significant decreases in protein, total amino acid, water and nitrogen content and increases in free fatty acid were observed in cotton bolls. Changes in quality of cotton bolls affected the growth, development and food utilization of H. armigera. Significantly longer larval development duration in three successive generations and lower pupal weight of the second and third generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower fecundity was also found in successive three generations of H. armigera fed on cotton bolls grown under elevated CO2. The consumption per larva occurred significant increase in successive three generations and frass per larva were also significantly increased during the second and third generations under elevated CO2. Significantly lower relative growth rate, efficiency of conversion of ingested food and significant higher relative consumption rate in successive three generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower potential female fecundity, larval numbers and population consumption were found in the second and third generations of cotton bollworm fed on cotton bolls grown under elevated CO2. The integrative effect of higher larval mortality rate and lower adult fecundity resulted in significant decreases in potential population consumption in the latter two generations. The results show that elevated CO2 adversely affects cotton bolls quality, which indicates the potential population dynamics and potential population consumption of cotton bollworm will alleviate the harm to the plants in the future rising CO2 atmosphere.     

Distributional dynamic and trend evolution of China’s agricultural carbon emissions – an analysis on panel data of 31 provinces from 2002 to 2011

Researching the dynamic distribution characteristics and trend evolution of agricultural carbon emissions is of considerable significance in formulating an effective agricultural carbon reduction policy. Based on measurement of agricultural carbon emissions of 31 provinces over the period 2002–2011, the study observed regional differences and the dynamic evolution of distribution of agricultural carbon emissions using agricultural carbon intensity as the indicator, accompanied by Gini coefficients and the kernel density estimation method. The results demonstrate first that agricultural carbon emissions for China show an obvious nonequilibrium nature in regard to spatial distribution. According to the differences in agricultural carbon emissions dynamic trends, we divided the 31 regions into four types – continuous decline, fluctuating decline, continuous increase, and fluctuating increase. Further, agricultural carbon emissions intensity showed a downward trend with significant differences in the research areas. Second, the gap in spatial distribution of national agricultural carbon emissions is gradually expanding based on the results calculated by Gini coefficient. From the perception of regional differences in agricultural carbon emissions, the eastern region showed an average level, the gap was more obvious in the central region, while western region showed a trend of fluctuating downward. Third, according to estimation by kernel density, the regional disparity in agricultural carbon emissions had a downward, but limited, trend. In regard to agricultural carbon emissions over the three areas, the regional gap not only tended to decrease but also showed a “four way” differentiation phenomenon in the eastern region. The difference in the central region difference was narrower. On the whole, the gap for the western region reduced steadily over a small range.     

Site‐Occupancy Distribution Modeling to Correct Population‐Trend Estimates Derived from Opportunistic Observations

Abstract: Species’ assessments must frequently be derived from opportunistic observations made by volunteers (i.e., citizen scientists). Interpretation of the resulting data to estimate population trends is plagued with problems, including teasing apart genuine population trends from variations in observation effort. We devised a way to correct for annual variation in effort when estimating trends in occupancy (species distribution) from faunal or floral databases of opportunistic observations. First, for all surveyed sites, detection histories (i.e., strings of detection–nondetection records) are generated. Within‐season replicate surveys provide information on the detectability of an occupied site. Detectability directly represents observation effort; hence, estimating detectablity means correcting for observation effort. Second, site‐occupancy models are applied directly to the detection‐history data set (i.e., without aggregation by site and year) to estimate detectability and species distribution (occupancy, i.e., the true proportion of sites where a species occurs). Site‐occupancy models also provide unbiased estimators of components of distributional change (i.e., colonization and extinction rates). We illustrate our method with data from a large citizen‐science project in Switzerland in which field ornithologists record opportunistic observations. We analyzed data collected on four species: the widespread Kingfisher (Alcedo atthis) and Sparrowhawk (Accipiter nisus) and the scarce Rock Thrush (Monticola saxatilis) and Wallcreeper (Tichodroma muraria). Our method requires that all observed species are recorded. Detectability was <1 and varied over the years. Simulations suggested some robustness, but we advocate recording complete species lists (checklists), rather than recording individual records of single species. The representation of observation effort with its effect on detectability provides a solution to the problem of differences in effort encountered when extracting trend information from haphazard observations. We expect our method is widely applicable for global biodiversity monitoring and modeling of species distributions.     

Global Major Progress and Trends in the Implementation of Agenda 21

This paper summarizes, from a global perspective, the major progress in the implementation of the Agenda 21 since the UN Conference on Environment and Development. The results show that global economy has achieved a substantial growth, and positive progress has been made in poverty eradication, urbanization, and conservation and intensive use of natural resources. However, relevant international conventions and commitments have not yet been completely fulfilled. The paper further analyzes the current major challenges and future trends of global sustainable development. It is argued that there are three major challenges:1) fatal global environmental issues posing an increasing threat to human survival; 2) more and more severe global competition for developing spaces; and 3) issues highlighting global people’s livelihood. There are four trends of global sustainable development:1) sustainable development will further turn from concept into global action; 2) green will be the main trend of global development; 3) emerging developing countries will become the main driving force of global sustainable development; and 4) international relations in the field of sustainable development will turn to competitive co-operation.     

Decabromodiphenylether and hexabromocyclododecane in wild birds from the United Kingdom, Sweden and The Netherlands: Screening and time trends

The brominated flame retardant decabromodiphenylether (DBDE) was analysed in wild birds to identify the most suitable species for monitoring time trends in DBDE contamination. This information was later used for the design of a 10-year trend study on DBDE in the European Union. DBDE was measured in muscle tissue, liver, and eggs from 10 terrestrial and four aquatic bird species. DBDE was detected in 47% of the terrestrial bird samples (nine species) and in 9% of the aquatic bird samples (six species). Peregrine falcon and sparrowhawk specimens were selected as most suitable species to determine temporal trends of DBDE. For sparrowhawks, no significant change in DBDE concentrations between 1973 and 2001 was found, although in later years more DBDE concentrations were above the detection limit. Peak DBDE levels measured in peregrines in 1995, were followed by a decline in concentrations until 2001. The same species were used for a trend study on hexabromocylcododecane (HBCD). Twenty-four percent of peregrine falcon eggs and 12% of sparrowhawk muscle samples demonstrated measurable HBCD residues. Three diastereomers of HBCD were analysed and the α-diastereomer was the predominant one in most samples. No clear time trends were observed for HBCD in either species. This study demonstrated that these DBDE and HBCD are bioavailable to birds of Northern Europe, although bioaccumulation seems to occur to a limited extent.