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1.
F. Valera C. Díaz-Paniagua J.A. Garrido-García J. Manrique J.M. Pleguezuelos F. Suárez 《Journal of Arid Environments》2011,75(12):1342-1351
Southern Spain’s semi-arid habitats are a Mediterranean ecosystem modelled mainly by historic factors which make them unique in comparison with North African deserts. Southern Spanish vertebrates have adapted to the recent emergence of semi-arid habitats in varying degrees of success. This paper reviews the current status of these terrestrial vertebrates (amphibians, reptiles, birds and mammals), their origins and their main features in relation to this biogeographic area. The vertebrate fauna of the semi-arid southeast of the Iberian peninsula differs widely from the one in the semi-arid Maghreb mainly because the former is composed by generalist vertebrates and much less so by species adapted to arid conditions. Moreover, a large fraction of the vertebrates in the semi-arid Iberia does not exploit the semi-arid areas but depends on riparian and human-managed habitats. The species diversity is rather low since only a small fraction of Palaearctic, European or Mediterranean species can adapt to the ecological limitations imposed by aridity and dwell in these semi-arid habitats. Such adaptations comprehend features like trophic plasticity, low morphological specialization, high dispersal ability, shortened life cycles and behavioural mechanisms to exploit the limited resources available. This paper identifies major conservation issues and proposes specific courses of action. 相似文献
2.
几种海洋蓝藻生长条件的研究 总被引：4，自引：0，他引：4
对Ｓｙｎｅｃｈｏｃｏｃｃｕｓ ｂａｃｉｌｌａｒｉｓ，Ｏｓｃｉｌｌａｔｏｒｉａ ｌｕｄ，Ｓｃｈｉｚｏｔｈｒｉｘ ｃａｌｃｉｃｏｌａ，Ｓｐｉｒｕｌｉｎａ ｐｌａｔｅｎｓｉｓ等４各海洋蓝藻的生长条件的研究表明，除Ｓ．ｐｌａｔｅｎｓｉｓ外，其他３种蓝藻在“ｆ／２”培养基中生长良好，外源生长因子对生长有不同程度的促进作用。Ｓ．ｂａｃｉｌｌａｒｉｓ适应较高光强，其温度和ｐＨ最适范围较窄，Ｓ．ｃａｌｃｉｃｏｌａ 相似文献
3.
王梅林 《中国海洋大学学报(自然科学版)》1987,(2)
每几个不同种的雌性克隆对高温(22℃、24℃、26℃)的适应力有所差异。大西洋沿岸的Laminariahyperhoren和L.sacchrina雌性克隆较太平洋沿岸的L.japonica、L.angustata和L.ochotensis雌性克隆明显地不耐高温,遗传性的不同是造成这种差异的主要原因。这种遗传性差异是海带长期自然选择的结果。同一物种L.japonica和L.japonicaCⅡ两种雌性克隆在24℃条件下,在第24天其死亡率分别是40.2％和25.2％,X~2=12.25,P<0.001,差异是高度显著的,说明这种不同是遗传性不同所致,而且属于物种内部的差异。 相似文献
4.
水平定向钻进地层适应性的评价方法 总被引：1，自引：0，他引：1
水平定向钻进的地层适应性对施工技术方案、钻具选择、参数选取和施工效益都有着重要影响。应采用钻进地层的岩土硬度、完整性和研磨性三方面指标,对比钻进技术工艺和技术器具特点,对钻进效率、钻孔的成孔和孔壁稳定性、以及钻具寿命等进行定性及定量的评价,从而有利于大大提高水平定向钻进铺管施工的技术和经济效益。 相似文献
5.
Yinhuang Irrigation District in Ningxia, as the top rice production area of high quality and quantity, has a long history in rice planting. The studies of the effective measures for the rice production replying the climate change were very important for reducing the harm of the future climate change and crop supply safety in Ningxia Province. Based on the coupling of the PRECIS model and the crop model CERES Rice, the effects of climate change on the rice production and growth stage in Yinhuang Irrigation District in Ningxia Province were simulated and evaluated, and the adaptability measures of rice production were studied. The results showed that the CERES Rice model had the preferable simulation capability, and the modified PRECIS model also could preferably simulate the required climate parameter. The crop model simulation results showed that the climate change had some influence on the rice production and growth stage in Yinhuang Irrigation District. The rice production goes down under future climate change scenarios in Ningxia Province. The trend of reduction of 2050s is more apparent than that of 2020s under the same scenarios,but the spatial change trend is similar. The extent and range of reduction of A2 scenario are wider than that of B2 scenario in the same period, but spatial change trend is different. For the change of growth stage, there has no obvious change in the north and the central part of the Yinhuang Irrigation District. The duration in 2050s shortens more obviously than that of 2020s under the same scenario, and the duration under B2 scenario shortens more obviously than that under A2 scenario in the same period. The results of adjusting the sowing date and the rice variety parameter G4 showed that the negative impact of climate change on the rice production can be reduced by sowing date advance in Yinhuang Irrigation District in Ningxia Province. There has obvious difference for the optimal G4 values of different region in Yinhuang Irrigation District, and the rice production can also be effectively upraised by adjusting the rice variety characteristic and cultivating the heat resistant rice varieties. The optimal G4 values can mitigate the damage of climate change on the rice production in Yinhuang Irrigation District in Ningxia Province. 相似文献
6.
《Marine Policy》2014
Fish producers' organizations (POs) bring together fishers or fish farmers on a voluntary basis so as to ensure the best market conditions for their fish. How fishers perceive and understand their membership experience is crucial to their capacity to learn from each other and adapt when interacting with their environment. These issues are explored by using the case of Propeixe, a Portuguese PO of purse seine fishers. Fishers ‘perceptions’ of their PO experiences are discussed using an analytical framework based on social learning literature. POs appear to stimulate social learning amongst fishers through changes in practices, economic and other incentives, rules and trust in leadership. Moreover, POs add to a simple market structure the properties of network coordination: interdependency and trust as a basis for co-operation. However, POs fail to change modes of interaction and communication amongst fishers. Within the PO network there are informal subnetworks, differing in terms of interests and influences, and disagreeing on problems (e.g. resource status) and on how to deal with them. By enhancing their members' social learning capacity, POs may increase their capacity to learn and cooperate with other actors in the sector. Leadership strategy, to encourage day-to-day dialog and deal with power relations, is essential in this respect. 相似文献
7.
为推动海洋资源的合理开发和有效保护,文章采用《资源环境承载能力监测预警技术方法(试行)》(《技术方法》)开展浙江省近岸海域海洋生态环境承载能力评价试点研究,验证指标体系和评价方法的适用性并提出建议。研究结果表明:《技术方法》的海洋环境承载状况评价结果更多代表氮磷水平,不足以客观反映海洋环境承载状况,而适应性验证方法的评价结果总体略好;海洋生态承载状况评价的适应性验证方法增加浮游植物参数,并以区域5年均值为基准,所得结果更为合理。针对《技术方法》的适用性问题以及业务化应用和管理的需求,建议:评价指标和具体参数的设置应考虑区位特点和自然属性,在海洋生态承载状况评价参数中增加浮游植物,并加长区域基准值的时间跨度;在集成评价时对指标设置较为合理的权重系数;加强中小尺度海洋生态环境承载能力研究;强化海洋生态环境承载能力评价与监测预警的结合应用。该研究成果可为进一步完善国家海洋生态环境承载能力监测预警工作提供技术支撑。 相似文献
8.
乌鳢的消化器官与其机能适应性的讨论 总被引：4，自引：0，他引：4
本文从乌鳢消化器官的形态学与组织学方面,就各消化器官与其机能的适应性作了初步探讨。各器官均与其食性和捕食方式相适应。 相似文献
9.
德国鲁尔区工业地域变迁的模式与启示 总被引：5，自引：0，他引：5
本文在分析鲁尔工业区的历史演变过程及其经济转型引起的失业,污染,停产,人口流失,社会形象下降等一系列问题的基础上,总结了鲁尔工业区改造过程中所采取的产业政策,政府导向,财政补贴和发展工业旅游景观的措施,介绍了埃姆什工业改造样板的发展。通过对鲁尔工业区地域结构转型模式,探讨了这一模式对我国东北老工业基地改造的启示。 相似文献
10.