Remarkable Species Diversity on Adjacent Salt Lakes in South Australia   总被引：1，自引：0，他引：1  

Peter HUDSON 《《地质学报》英文版》2014,88(Z1):73-73

正Lakes Acraman,Gairdner,Harris and Everard are a cluster of large episodic salt lakes on Eyre Peninsula,South Australia.These lakes have a characteristic terrestrial invertebrate fauna including various spiders,  相似文献   

雷州半岛灯楼角珊瑚礁海区夏季的浮游动物   总被引：6，自引：0，他引：6       下载免费PDF全文

尹健强  黄晖  黄良民  李开枝  练健生 《海洋与湖沼》2008,39(2):131-138

2004年8月在雷州半岛灯楼角珊瑚礁海区分别使用浅水Ⅰ型和浅水Ⅱ型浮游生物网进行了浮游动物调查,共鉴定浮游动物72种和浮游幼虫19个类群(或类型),其中桡足类的种数最多达45种。结果表明,浮游动物种数分布由近岸往远岸递增,约3/4的种类属于终身浮游生物,1/4属于阶段性浮游生物。中小型的浮游动物种类多,数量大。两种网具采集的浮游动物总种数、总密度、多样性指数、均匀度和中小型优势种的密度差异相当显著,而大型优势种的密度差异不明显。用浅水Ⅱ型网采集的浮游动物总密度平均值为5270ind/m3,是浅水Ⅰ型网的110倍。桡足类占浮游动物总密度的72.45%,其次幼虫占23.41%。浮游动物密度呈斑块状分布,最高达16257ind/m3,底质为珊瑚礁的测站的浮游动物数量一般较多。优势种主要是中小型种类和底栖动物的幼虫,如强额孔雀哲水蚤、蔓足类无节幼虫、细长腹剑水蚤、驼背隆哲水蚤、无节幼虫、双壳类面盘幼虫、桡足幼体、简长腹剑水蚤等。  相似文献   

Preserving coastal natural character: Court interpretations of a long‐standing New Zealand policy goal          下载免费PDF全文

Victoria Ann Froude 《New Zealand geographer》2015,71(1):45-55

New Zealand's policy goal to preserve coastal natural character was first incorporated into planning legislation in 1973 and protected area legislation in 1977. An evaluation of 100 relevant Resource Management Act Court decisions determined the Courts' interpretations of this policy goal. The Courts have repeatedly found that natural character is of nature (not culture), including natural elements, patterns, and processes. There is a continuum of naturalness from pristine indigenous ecosystems to the urban environment. A 2014 Supreme Court decision has upheld the use of environmental bottom lines for natural character and the importance of protection as part of sustainable management.  相似文献   

Alternative climate policy pathways in the US     

Robert MacNeil 《Climate Policy》2013,13(2):259-276

Although it is likely that the political–economic coalition required for implementing a federal cap-and-trade programme for GHGs in the US is now sufficiently strong, the structural impediments that have prevented its legislative passage remain impressively durable and can be expected to continue to lay waste to congressional proposals for the foreseeable future. Indeed, given the complex history of environmental policy gridlock in Washington since the early 1980s, any expectations that a cap-and-trade programme could have been realistically achieved through the traditional legislative passage in Congress are fundamentally misplaced. Building on previous research, it is argued that – as with most other forms of environmental policy in the US over the past three decades – a national carbon market is more plausible given alternative policy pathways, which if taken are capable of circumventing the Federal Congress altogether. In particular, the interaction between litigation against the federal government and the ‘rulemaking’ authority possessed by the Executive Branch provides the potential space for the current administration to unilaterally establish a model rule for a national carbon-trading programme.

Policy relevance

This article aims to contribute to American climate policy debates by re-thinking the policy mechanisms most capable of establishing a national carbon market in the US. By taking into account the array of structural factors that have prevented the legislative passage of such a programme in federal Congress, a range of alternative policy ‘pathways’ is considered that have historically allowed progressive environmental policies to endure in Washington (despite increased Congressional gridlock over the past few decades). Two specific alternative strategies and the relationship between them are assessed: the use of litigation to impose legal obligations on federal agencies to regulate effluents, and the use of executive authority to define the nature and scope of environmental regulation. The administration's current potential to unilaterally develop a model-rule for a cap-and-trade programme under the Clean Air Act is emphasized, and the political implications of such a strategy are considered.  相似文献   

偏硼酸锂溶液物种分布和物化性质          下载免费PDF全文

许沙  房艳  房春晖  周永全  朱发岩  陶松 《盐湖研究》2012,20(3):37-42

测量了不同浓度LiBO2溶液分别在298.15和323.15 K的密度、电导和pH,通过测得的pH和硼酸根离子化学平衡常数计算得到溶液中硼酸根离子的物种分布。根据获得的物种分布结果,推测溶液中各硼酸根离子之间的相互转化过程,并分别用偏摩尔体积公式和Onsager方程对溶液偏摩尔体积及摩尔电导率进行计算并拟合。对计算得到偏摩尔体积值和极限摩尔电导率值与文献报道的数据进行对比,计算结果与文献报道值吻合较好。  相似文献   

广西北仑河口红树林湿地大型底栖动物多样性的初步研究   总被引：1，自引：0，他引：1  

何祥英  苏搏  许廷波  农立成  叶朝放  李啸宇 《湿地科学与管理》2012,8(2):44-48

2010年7月对广西北仑河口红树林湿地的大型底栖动物进行调查,共发现大型底栖动物8门10纲46科106种,其中软体动物49种,甲壳类36种,多毛类10种,其它类11种。生物量优势种和密度优势种都是软体动物门的珠带拟蟹守螺。大型底栖动物平均生物量是103.09g/m2,平均密度是196个/m2。与历史调查数据比较,本次调查发现了69种本地新种;对比国内6个红树林区底栖动物群落结构,其生物量及栖息密度属于中等偏下,物种多样性指数高于其它红树林区。结果表明:底栖动物的生物量及栖息密度与红树林发育状况呈负相关的关系,物种多样性与红树林发育状况呈正相关的关系。  相似文献   

Variations in species richness in hay-meadow vegetation at Voss,west Norway,in relation to long-term management practices     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(2):77-84

Because of its species-rich hay meadows and old pollards that are traditionally managed, Ulvund in Myrkdalen, Voss, is one of 14 areas in Hordaland county that are considered to be of special interest for cultural landscape conservation. The spatial patterns of species richness were investigated in hay meadows at Ulvund. Two main types of vegetation were recognised in managed meadows. Unfertilised and species-rich areas with a rather short field layer were situated in the steep parts of the meadows. Fertilised and species-poor areas with a high field layer were situated on flat or gently sloping areas. This spatial pattern is recognised in other west Norwegian hay meadows as well and is very likely linked to historical differences in land management; the flatter areas were formerly used as heavily fertilised permanent tilled fields for grain production, while the steep areas were used for hay production. As the conservation value largely lies in small, localized parts of the farms, conservation management actions can also be localized and thus feasible under modern conditions.  相似文献   

Economic benefit of the protection program for the Steller sea lion     

Kelly Giraud  Branka Turcin  John Loomis  Joseph Cooper 《Marine Policy》2002,26(6)

This paper examines willingness to pay (WTP) for an endangered species across geographically nested samples using the Contingent Valuation Method (CVM). The three samples range from (1) the boroughs that contain critical habitat for the Steller sea lion to (2) the state that contains these boroughs to and (3) the entire United States. Depending on the assumptions of the model, WTP varies tremendously from sample to sample. WTP for the United States is the highest and it is the lowest for the boroughs. The null hypotheses that mean WTP estimates are greater then zero were rejected for the boroughs and the state but were not rejected for the United States based on the 95% confidence intervals.  相似文献   

中国濒危淡水鱼类致危成因分析   总被引：4，自引：0，他引：4  

乐佩琦 《湖泊科学》1995,7(3):271-276

中国１０００多种淡水鱼类因受水工建设、围湖造田、乱伐滥垦等改变和破坏水域环境、酷渔滥捕,水体污染,不合理引种,法制不全及执法不力等原因导致部分鱼类濒危。初步确定为９２种,分属９目,２４科,７８属,根据程度分为四个等级,绝灭４种,稀土２３种,濒危２８种,渐危３７种。  相似文献   

渤海海区无机硒的形态及其分布   总被引：2，自引：1，他引：1  

姚庆祯  张经 《海洋与湖沼》2004,35(3):221-229

1998年9月利用氢化物发生原子荧光光谱测试方法对渤海中央海区共8个断面30个站位的无机硒进行了测定。结果表明,渤海无机硒总量、Se4^ 含量的变化范围分别为0.73-2.57nmol／L、0.18-0.72nmol／L,平均含量分别为1.31nmol／L和0.47nmol／L;Se^4 ／Se^6 比值的平均值为0.68。渤海无机硒的含量与大洋水相当,无机硒主要以Se^6 为主。黄河对渤海的贡献非常明显,为渤海无机硒的主要来源之一。渤海无机硒的平面分布存在明显的梯度,沿岸向中央海区递减,垂直分布较均匀,表、底层差别不大。渤海无机硒的分布明显受两个水团的影响：一个是来自黄河的冲淡水,另一个是从渤海海峡北部进入的黄海水团。  相似文献