Impact of climate factors on cyanobacterial dynamics and their interactions with water quality in South Taihu Lake,China

Cyanobacterial bloom events in South Taihu Lake cause serious water quality problems and disturb aesthetic view of lake’s environment. In this study, correlations between cyanobacterial blooms and hydro-meteorological factors, including water quality, temperature and precipitation were investigated. Results demonstrated that South Taihu Lake was heavily affected by cyanobacteria and the proliferation of cyanobacteria due to variations in hydro-meteorological factors and water quality conditions. Water quality parameters, including COD, NH₃-N, TN and TP improved significantly since 2008 even at an elevated cyanobacterial bloom situation. Correlation analyses have shown that the development of cyanobacterial density and chlorophyll a concentration was sensitive to a wider temperature variation. The optimum temperature for cyanobacteria was 20°C, while extremely low and high temperatures were found to suppress their growth. Moreover, unusual rainfall patterns were measured during the study period (2003–2009), which showed an adverse impact on cyanobacterial development. Findings from this study suggested that seasonal lake’s water quality monitoring; suitable treatment of cyanobacterial blooms and strict policy implementation can solve the water quality issues in highly eutrophic lakes like Taihu.     

1980年以来中国大宗作物空间格局变化分析

利用1980～2014年间的大宗作物(玉米、水稻、小麦、棉花、油菜)面积数据,以省级行政区为研究单元,采用多种数理统计和GIS空间分析技术,结合同期作物之间的竞争性用地关系,对全国上述五类大宗作物的空间分布格局及其变化特征进行分析.研究结果表明:玉米的空间分布相对较均衡;小麦的空间格局总的变化不明显但是省际分布最不均衡;棉花近30 a来空间格局变化极其显著,其面积重心从河南境内不断地向西北地区移动,目前位于甘肃省境内;油菜的面积重心自湖北境内不断地向南推移到湖南境内,水稻的面积重心则自江西境内逐渐向北移动到湖北境内.另外,部分区域的同期作物(如油菜与小麦、棉花与春玉米)空间格局变化存在明显的“消-长”关系,特别是在甘肃和内蒙,油菜小麦的面积变化有着极强的负相关性,其pearson系数低于-0.8.作物种植的成本收益变化是造成这些大宗作物空间格局变化的主要原因,城市化发展的程度、农民非农就业机会的高低、同期作物之间的比较效益差距等也是这些大宗作物时空格局产生变化的重要原因.     

Climate Change Coverage in Greek Newspapers: 2001–2008

This paper's aim is to identify the debate and document the coverage of climate change (CC) in the Greek national press and to assess to what extent this reporting exhibits the traits anticipated by the “polarized pluralist” character of the Greek “media system.” In order to do this, we analyzed articles published in three Greek quality newspapers (Kathimerini, Ta NEA, and Eleftherotypia) over the period 2001–2008 (N =2072). Our findings suggest a mixed picture: the Greek media debate is characterized by consensus on the anthropogenic causes of CC and on the promotion of renewable energy sources as a means for tackling Greek CC-related emissions. However when examining more specific/controversial CC-policy decisions, there is less evidence supporting a close link with the national character of Greek media reporting, with newspapers appearing to align themselves along partisan lines.     

Addressing challenges for future strategic‐level emergency management: reframing,networking, and capacity‐building

The mounting frequency and intensity of natural hazards, alongside growing interdependencies between social‐technical and ecological systems, are placing increased pressure on emergency management. This is particularly true at the strategic level of emergency management, which involves planning for and managing non‐routine, high‐consequence events. Drawing on the literature, a survey, and interviews and workshops with Australia's senior emergency managers, this paper presents an analysis of five core challenges that these pressures are creating for strategic‐level emergency management. It argues that emphasising ‘emergency management’ as a primary adaptation strategy is a retrograde step that ignores the importance of addressing socio‐political drivers of vulnerabilities. Three key suggestions are presented that could assist the country's strategic‐level emergency management in tackling these challenges: (i) reframe emergency management as a component of disaster risk reduction rather than them being one and the same; (ii) adopt a network governance approach; and (iii) further develop the capacities of strategic‐level emergency managers.     

气候变化对鄱阳湖流域干旱灾害影响及其对策

以我国历史气候变化的事实与过程重建的成果为基础，以历史文献为依据，分析了两宋以来鄱阳湖流域气候变化与洪水干旱灾害发生的关系，结果表明，不管气候处于温湿期还是冷干期，发生洪水灾害的频率没有显著区别；但是当气候处于冷干时期，发生干旱灾害的频率增大，特大干旱年和连续干旱年组频频出现。利用气象、水文资料统计分析表明，最近60 a来，气温呈现增高趋势，逐年的日降水强度明显增加，洪水干旱等极端事件发生更加频繁。为了更好地应对干旱灾害，必须加强水需求管理、坚持节约用水为先；加强病险水库的治理，使其充分发挥作用；对现有水利工程进行再评估，实施适应性管理，充分挖掘工程潜力；加大力度，新建与自然和谐相处的水利工程     

Effects of Widespread Drought‐Induced Aspen Mortality on Understory Plants

Forest die‐off around the world is expected to increase in coming decades as temperature increases due to climate change. Forest die‐off will likely affect understory plant communities, which have substantial influence on regional biological diversity, ecosystem function, and land–atmosphere interactions, but how die‐off alters these plant communities is largely unknown. We examined changes in understory plant communities following a widespread, drought‐induced die‐off of trembling aspen (Populus tremuloides) in the western United States. We assessed shrub and herbaceous cover and volume in quadrats in 55 plots located across a wide range of levels of aspen mortality. We measured species richness and composition of herbaceous plant communities by recording species presence and absence in 12 sets of paired (1 healthy, 1 dying) aspen plots. Although understory composition in healthy and dying stands was heterogeneous across the landscape, shrub abundance, cover, and volume were higher and abundance of herbaceous species, cover, and volume were lower in dying aspen stands. Shrub cover and volume increased from 2009 to 2011 in dying stands, which suggests that shrub growth and expansion is ongoing. Species richness of herbs declined by 23% in dying stands. Composition of herbs differed significantly between dying and healthy stands. Richness of non‐native species did not differ between stand types. The understory community in dying aspen stands was not similar to other shrub‐dominated plant communities in the region and may constitute a novel community. Our results suggest that changes in understory plant communities as forests die off could be a significant indirect effect of climate change on biological diversity and forest communities. Efectos de la Mortalidad Extensiva de Álamos Inducida por Sequía sobre Plantas del Sotobosque     

1961～2010年江浙沪地区夏季高温热浪时空变化特征

利用我国江浙沪地区26个气象站1961～2010年夏季(6～8月)逐日最高气温资料,选择导致死亡率突然增加而确定的高温热浪指标,研究了江浙沪地区高温热浪日数、频次和强度的时空分布特征.结果表明江浙沪地区是高温热浪天气的高发区,高温热浪天气存在显著的地理差异.江浙沪地区平均高温热浪日数、频次和强度随时间的变化趋势极为相似:20世纪60年代至80年代前期呈现减少(弱)趋势,80年代后期呈现增多(强)趋势.总体上看,江浙沪地区受高温热浪袭击时间越来越长,频率越来越高.近50a江浙沪地区夏季高温热浪天气呈南转的趋势.高温热浪天气受全球变暖与城市热岛效应的共同影响而逐渐加剧.     

Assessing the shelf life of cost‐efficient conservation plans for species at risk across gradients of agricultural land use

High costs of land in agricultural regions warrant spatial prioritization approaches to conservation that explicitly consider land prices to produce protected‐area networks that accomplish targets efficiently. However, land‐use changes in such regions and delays between plan design and implementation may render optimized plans obsolete before implementation occurs. To measure the shelf life of cost‐efficient conservation plans, we simulated a land‐acquisition and restoration initiative aimed at conserving species at risk in Canada's farmlands. We accounted for observed changes in land‐acquisition costs and in agricultural intensity based on censuses of agriculture taken from 1986 to 2011. For each year of data, we mapped costs and areas of conservation priority designated using Marxan. We compared plans to test for changes through time in the arrangement of high‐priority sites and in the total cost of each plan. For acquisition costs, we measured the savings from accounting for prices during site selection. Land‐acquisition costs and land‐use intensity generally rose over time independent of inflation (24–78%), although rates of change were heterogeneous through space and decreased in some areas. Accounting for spatial variation in land price lowered the cost of conservation plans by 1.73–13.9%, decreased the range of costs by 19–82%, and created unique solutions from which to choose. Despite the rise in plan costs over time, the high conservation priority of particular areas remained consistent. Delaying conservation in these critical areas may compromise what optimized conservation plans can achieve. In the case of Canadian farmland, rapid conservation action is cost‐effective, even with moderate levels of uncertainty in how to implement restoration goals.     

Integrated Approaches to Natural Resources Management in Practice: The Catalyzing Role of National Adaptation Programmes for Action

The relationship of forests in water quantity and quality has been debated during the past years. At the same time, focus on climate change has increased interest in ecosystem restoration as a means for adaptation. Climate change might become one of the key drivers pushing integrated approaches for natural resources management into practice. The National Adaptation Programme of Action (NAPA) is an initiative agreed under the UN Framework Convention on Climate Change. An analysis was done to find out how widely ecosystem restoration and integrated approaches have been incorporated into NAPA priority adaptation projects. The data show that that the NAPAs can be seen as potentially important channel for operationalizing various integrated concepts. Key challenge is to implement the NAPA projects. The amount needed to implement the NAPA projects aiming at ecosystem restoration using integrated approaches presents only 0.7% of the money pledged in Copenhagen for climate change adaptation.