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51.
52.
Bue Nielsen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):62-69
Nielsen, Bue: Employment and economic activities in the EC. Geografisk Tidsskrift 84: 62–69. Copenhagen January 1984. Regional disparities in unemployment and economic activities in the EC in the late 1970'es. Various concepts of unemployment are discussed. The performance of regions and countries using different concepts are illustrated. 相似文献
53.
《Marine Policy》2014
The management of marine ecosystems requires adequate knowledge of both environmental and human dimensions, as well as their interrelationships. In this study, the aquaculture and fisheries activities are analyzed in one of most important fishing regions in Europe, Galicia (NW Spain). In particular, the intensity and characteristics of the fishing dependency are evaluated in terms of income and employment. Thus, nine marine economic activities for nine Maritime Zones have been defined, considering the social and economic relevance of the provided ecosystem services to these communities. This paper highlights the entire Galician coast as fishing-dependent, independently of the urbanization level. Furthermore, the contribution of different fishery segments to the income and employment of these coastal communities is reviewed, including fluctuations on whether the activity is small or large-scale. Finally, this study establishes a strong relationship among the marine activities, which generate most employment, and the regulatory framework of the Regional Government. Therefore, the conclusions are relevant to design and implement policies that affect Galicia׳s Region and all its related marine ecosystems. 相似文献
54.
Although microbes have traditionally been used as models for testing ecological theory, research on the organization of these communities has largely been isolated from other areas of community ecology. Early studies indicated that microbial populations can form dynamic, interacting assemblages. Observations of distributional patterns suggest that certain deterministic forces regulate community structure. It appears that protozoans are tolerant of a wide range of environmental conditions although evidence for this is largely based on gross environmental analyses. Laboratory studies have suggested the importance of negative and positive biotic interactions in determining community membership, but little field evidence for this exists. The importance of transport processes in controlling community composition is being increasingly recognized. All three types of processes likely act to regulate the colonization and successional dynamics of these communities. A simple model is presented to promote the devel 相似文献
55.
为研究内陆盐沼植物群落的分布对土壤盐分的响应特征,选取鄂尔多斯盐湖盐沼区作为研究区,筛选了肉质耐盐植物群落、苔草植物群落和禾草植物群落3类典型植物群落,开展了土壤含水量、pH、电导率以及Na+、K+、Mg2+、Ca2+、Cl-、SO42-、CO32-和HCO3-测定,分析了区内典型植物群落对土壤水盐因子的响应规律。探讨了3类植物群落之间土壤因子含量的差异性;采用相关性分析和CCA分析,评价了3类植物群落多样性及物种分布随土壤因子的变化规律。结果表明,区内3类植物群落中,土壤盐分含量表现为肉质耐盐植物群落最高,苔草植物群落最低,禾草植物群落居中;植物多样性与土壤中含量最高的Na+和SO42-的相关性最显著;植物分布同时受到土壤盐分、水分和pH的显著影响。研究结果可为鄂尔多斯盐湖区土壤盐... 相似文献
56.
Spatial distribution of crustaceans associated with shallow soft‐bottom habitats in a coral reef lagoon 下载免费PDF全文
The ecology and diversity of the shallow soft‐bottom areas adjacent to coral reefs are still poorly known. To date, the few studies conducted in these habitats dealing with macroinvertebrate fauna have focused on their abundance spatial patterns at high taxonomic levels. Thus, some aspects important to evaluate the importance and vulnerability of these habitats, such as species diversity or the degree of habitat specialization, have often been overlooked. In this study we compared the crustacean assemblages present in four different habitats at Magoodhoo Island coral reef lagoon (Maldives): coral rubble, sandy areas and two different seagrass species (Thalassia hemprichii and Cymodocea sp.). Forty‐two different crustacean species belonging to 30 families and four orders were found. ‘Site’ was a significant factor in all of the statistical analyses, indicating that tropical soft‐bottom habitats can be highly heterogeneous, even at a spatial scale between tens and hundreds of meters. Although traditionally it has been considered that seagrass beds host greater species diversity and abundance of organisms than adjacent unvegetated habitats, no differences in the univariate measures of fauna (abundance of organisms, number of species and Shannon diversity) were observed among habitats. However, sandy areas, coral rubble and seagrass beds exhibited different species composition of crustacean communities. The percentage of taxa considered as potential habitat specialists was 27% and the number of species exclusively occurring in one habitat was especially high in seagrass beds. Thus, degradation of this vegetated habitat would result in a great loss of biodiversity in tropical shallow soft‐bottom habitats. 相似文献
57.
南京市城市老年人出行行为的影响因素 总被引:1,自引:0,他引:1
老年人在人口比例和绝对数量上的快速增长将对整个社会产生一系列影响,其中交通出行是非常重要的一个方面。本文基于2012年南京居民出行调查数据,发现相对于年轻人,老年人的日出行次数增加,但日出行时间和日出行距离都减少,说明老年人单次出行距离较短,且主要围绕“家”形成圆形的活动空间;从出行方式构成来看,老年人以步行和公交车为主,出行目的以娱乐、休闲和购物为主。运用次序Logit及线性回归模型,在确定老年人及其家庭的基本社会经济属性之后,发现城市建成环境对老年人的出行有显著影响。其中,城市人口密度会显著增加老年人的日出行次数,但其日出行距离反而有所减少;居住在原单位小区的老人日出行次数比居住于商品房的老人多,且出行距离也较短;说明混合用地以及紧凑的发展模式有利于促进老年人的出行。距离交通基础设施越近,老年人的出行越活跃。大型购物中心对老年人的购物出行没有显著影响,老年人更倾向于在街头小店购买物品。而小区周边体育馆、博物馆等设施对老年人的吸引力则不如棋牌室和公园广场。研究结果对老年人健康生活和科学合理布局城市设施具有一定的指导意义。 相似文献
58.
K. B. Lewis 《新西兰海洋与淡水研究杂志》2013,47(4):663-670
Sixteen rock samples were collected from the continental shelf and slope between Napier and Cape Turnagain, southern Hawkes Bay, most coming from offshore anticlinal ridges. Nine of the samples have a foraminiferal fauna of Upper Miocene and Pliocene age. The remainder cannot be dated, but most are probably of similar age. The foraminiferal. faunas are considered to have lived at depths ranging down to at least 1600 m deeper than the depth from which they were collected. Thus, the post‐depositional history of the samples includes tectonic uplift of similar magnitude since Upper Tertiary times. Because most of the samples arc very fine grained, unlike Recent sediments from ridges, it is suggested that the present regime of folding is largely post‐Pliocene in age. 相似文献
59.
中国老年人空间行为研究进展 总被引:6,自引:1,他引:5
中国人口老龄化及空巢化现象的加快使得老龄问题受到学者关注.老龄化进程和养老模式等宏观层面的研究为中国老龄工作的开展提供政策指导,而政策的落实状况及其对老年人生活的影响需要从微观层面通过空间行为分析来还原老年人个体与环境之间的互动关系.本文从空间行为的视角对国内多个学科的老年人日常行为相关研究进行评述.基于对老年人生活方式及需求层次理论的认知,文章聚焦中国老年人日常生活的主体行为:就医行为、购物行为和休闲行为,梳理这3 类行为的国内研究发展历程及其行为特征、影响机制分析等主要研究结论.基于时空间尺度和出行链进行了中国老年人空间行为研究的地理学探讨,并结合国际老年地理学的研究发展,提出了老年人空间行为研究的展望. 相似文献
60.