The coccolithophore summer–autumn assemblage in the upwelling waters of Portugal: Patterns of mesoscale distribution (1985–2005)     

M.T. Moita  A. SilvaS. Palma  M.G. Vilarinho 《Estuarine, Coastal and Shelf Science》2010

A study of the mesoscale distribution of phytoplankton communities observed along the Portuguese upwelling coast in 1985–1986 made it possible to identify an assemblage composed by the coccolithophores Helicosphaera carteri, Syracosphaera pulchra and Coronosphaera mediterranea. The assemblage was consistently present in the coast in the following years (1991, 1992, 1994, 2003 and 2005) and from 1992 onwards, Rhabdosphaera clavigera was recognised as being part of it, although in low concentrations During late summer, this group of species showed higher affinities with upwelling waters of subtropical origin (ENACWst) on the SW coast. At the end of the upwelling season, in autumn, the assemblage was advected to the NW shelf due to the intensification of the poleward surface circulation or meridional seasonal changes of environmental conditions. The species maximum abundances were not coincident in space: H. carteri developed at the central part of the western coast while blooms of S. pulchra and C. mediterranea generally occurred further south, such as at the upwelling centre of cape S. Vicente. Syracosphaera pulchra blooms were characterised by lower concentrations of C. mediterranea and vice-versa. The above patterns were recurrent along the years but the relative abundance of each species appeared related to the interannual variability of physical conditions as the upwelling.  相似文献   

皱纹蛤的生态观察     

黄洋  劳赞  杜涛 《广东海洋大学学报》2007,27(6):80-83

<正>皱纹蛤Periglypta puerpera(Linnaeus,1771)隶属帘蛤目Veneroida、帘蛤科Veneridae、皱纹蛤属Periglypta。目前国内只有分布和外部形态上的一些描述[1~2],对其生态习性尚无详细的研究。笔者从2004年1月至2005年3月,对雷州半岛西部流沙湾皱纹蛤的生态进行了实验和观察,现报道如下。  相似文献   

绿色建筑的内涵及其发展的若干思考     

罗栋燊廖福霖  官巧燕郑国诜 《亚热带资源与环境学报》2006,1(2):84-87

随着我国城市化进程的快速推进，大规模的人居环境建设使我国的资源与环境面临巨大的挑战，发展绿色建筑已经成为可持续发展的重大战略问题．文章从可持续发展的角度，指出了绿色建筑的内涵与特征，并归纳了绿色建筑与一般建筑的区别．在此基础上，提出了发展绿色建筑的具体对策．  相似文献   

碳循环及对气候变化和人类生存环境的影响   总被引：3，自引：3，他引：3  

张佳华  卞林根  延晓冬  姚凤梅 《气象科学》2006,26(3):350-354

碳循环及全球变暖已成为影响气候变化、人类生存环境和经济共同发展和安全的重大问题,引起了全球科学、政治、外交政策等部门的重视。本文着重探讨碳循环的由来、生态系统与碳循环的科学相关、在碳循环方面,中国需要解决的问题和科学技术方法以及碳循环系统的科学研究方法和改进等问题。  相似文献   

开展中国大陆水圈演化研究，保护人类生存环境   总被引：1，自引：0，他引：1  

张宗祜  任福弘  费瑾  朱延华 《地球学报》1995,16(1):22-27

中国大陆水圈是地球水圈的重要组成部分。青藏高原的阶段性急剧隆起和全新世以来的持续上升，控制着中国大陆水圈的自然演化方向和速率。中国大陆水圈演化在研究地球陆地水圈方面有其特殊意义。近几十年来，随着国民经济建设的发展及人类工程技术活动的加强，导致地表河流流量及入海水量减少、地下水位大面积下降和地面沉降、地表水和地下水水质恶化、海水入侵地下水含水层等等，这些都积极地改变着中国大陆水圈的自然状态，从而影响人类的生存环境。因此，开展中国大陆水圈演化研究──中国大陆水圈量与质的演化过程、中国大陆水圈与其它圈层间的相互作用、人类社会经济活动对中国大陆水圈演化影响与反馈、水环境演化趋势及资源环境效应预测等，不仅是我国地球科学与国际研究接轨的需要，也是保护人类生存环境最基本的重大课题。  相似文献   

居民对生活质量评估与区域经济发展的定量分析   总被引：12，自引：1，他引：12  

李小建  乔家君 《地理科学进展》2002,21(5):484-490

通过对全国 1 5个省份 1 9个县 (市 )近万户调查数据的分析得出 :居民对自己生活状况的主观评价与区域经济发展水平并不呈现显著正相关关系 ;居民对自己生活状况的满意程度在城乡间、县际间存在一定差异 ,一般为城市高于农村。不同县域居民对影响其生活质量的主要因子的认识有很强的一致性。区域发展研究中 ,应当关注居民生活质量评估指标。  相似文献   

山东黄河下游地区局部生态地球化学评价方法与技术   总被引：3，自引：0，他引：3       下载免费PDF全文

庞绪贵  战金成  宋海林  藤兆令  李秀章  王增辉  代杰瑞 《山东国土资源》2006,22(5):28-33

山东黄河下游地区局部生态地球化学评价是在多目标区域地球化学调查和区域生态地球化学评价基础上,选特色农产品产地,绿色无公害蔬菜生产基地,地方病分布区及小清河沿岸、东营油气开采污染区等局部生态地球化学环境区。按一定的方法和采样密度采集土壤、浅层地下水、土壤溶液、植物根系土、籽实、土壤生物、微生物和种子库样品,分析As,Cd等重金属元素、N,B等有益营养元素、六六六、DDT等有机物和土壤微生物类群、功能、结构多样性,研究有益营养元素、重金属元素、有毒有机污染物的分布规律、赋存状态、来源及它们在土壤、水体及生物体中的迁移、转化、累积规律与生态效应,探讨对重金属元素污染的生物修复。提出特色农产品基地布局规划建议和地方病防治、重金属污染的治理措施。  相似文献   

Rural restructuring in Hungary in the period of socio-economic transition   总被引：10，自引：0，他引：10  

Eva Kiss 《GeoJournal》2000,51(3):221-233

Rural settlements in Hungary account for 93% of all settlements and 37% of the country's population. Since 1989 they are scenes of spectacular changes. Based on some case studies of less developed villages this paper considers the most important characteristics of the post-socialist rural transformation by examining the local economy and living conditions. The main issues are how local actors (for example, economic corporations, households and individuals) have been affected by the interaction of supralocal and local factors and how they responded to them. Such responses can be considered to be manifestations of survival strategy.  相似文献   

A preliminary assessment of social risk in Romania   总被引：1，自引：0，他引：1  

Liliana Guran  David Turnock 《GeoJournal》2000,50(2-3):139-150

Social risk is seen as endemic in the postmodern world of 'glocalisation', especially in cities competing for a place in the global economy while simultaneously seeking to contain tensions between a kaleidoscopic mix of urban interests and life styles. Transition economies in Eastern Europe are very much at risk, especially in southeastern Europe where a general decline in living standards heightens tension as large cities are threatened with heavy unemployment. Several indicators of social risk are examined at the county level in Romania, but it is evident that while there are some close correlations between unemployment on the one hand and labour unrest, divorce and criminality on the other this is not always the case. Some counties have remained stable despite high unemployment while others manifest high social risk with below-average unemployment. Further research is needed to assess risk on a regional basis more accurately, but it is clear that the electorate will continue to vent its anger on incumbent governments when necessary restructuring does not immediately attract new investment and job creation. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

浑善达克沙地黄柳活沙障防风固沙效益的研究   总被引：14，自引：1，他引：13  

张瑞麟  刘果厚  崔秀萍 《中国沙漠》2006,26(5):717-721

通过研究浑善达克沙地流动沙地上黄柳活沙障的防风固沙效益,对设置3 a后的不同类型的活沙障进行测定和分析,得出如下结论:沙障设置3 a后,沙地趋于固定,障内植物种类明显增多;设置黄柳活沙障的区域内下垫面粗糙度显著增大,风速明显减弱,而且黄柳网格沙障降低风速的能力较带状沙障强,其顺序为:4 m×4 m黄柳网格沙障>6 m×6 m黄柳网格沙障>间距4 m的黄柳带状沙障>间距6 m的黄柳带状沙障﹥流沙;当旷野平均风速为7.86 m·s-1时,只有流沙和间距6 m的黄柳带状沙障起沙,其他几类活沙障内均不起沙。  相似文献