Forest leaf litter quantity and seedling occurrence along an urban-rural gradient

Leaf litter, by modifying microenvironmental conditions, can alter plant population distributions and is considered to be a major force in structuring many plant communities. Comparative studies of urban, suburban, and rural forests in the New York City (NYC) metropolitan area have identified numerous biotic and abiotic differences among these forests, including several involved in leaf litter decomposition. These differences in decomposition among the forests could result in differences in litter quantity on the forest floor and hence microenvironmental conditions and safe sites for germination of different plant species. We conducted a survey of forest floor leaf litter quantity in forests located along an urban-to-rural land-use gradient originating in urban NYC and extending to rural Connecticut. Mean litter depth, mass, and density increased significantly with increased distance of the forest from NYC.We also surveyed woody seedlings and compared the litter depth in which they naturally occurred to the mean litter depth of the surrounding forest. Seedlings of small-seeded species were much more likely to be located in litter shallower than mean forest litter depth than were seedlings of large-seeded species. Taken together, these results suggest that environmental changes associated with urbanization may have profound effects on long-term patterns of forest regeneration.     

立足海洋资源优势 全方位发展蓝色经济

建设山东半岛蓝色经济区,要立足海洋资源优势,推进传统领域集约发展,进一步用好海洋资源优势;推进新兴领域快速发展,全方位拓展海洋资源优势;推进强势领域高端发展,深层次放大海洋资源优势;推进发展环境优化,全面提升海洋资源利用水平,全方位发展蓝色经济。     

西部地区土地利用变化对生态系统服务价值的影响——以宝鸡市为例

土地利用结构的变化引起各类生态系统类型、面积以及空间分布格局的变化.针对宝鸡市在2002-2007年5年间,林地面积增加,耕地和未利用地面积减少,土地利用结构变化引起生态服务价值的变化,区域人均生态系统服务价值下降这一现象,进行了定量化的研究,论述了宝鸡市土地利用方式与生态系统服务价值之间的动态联系,为衡量区域生态环境质量,实现土地资源优化配置,提供了有益的依据.     

连云港市工业化与城市化互动发展的制约因素探讨

工业化与城市化是同一经济过程两个不同侧面的反映。通过相关数据对连云港市工业化与城市化发展现状进行实证分析,研究连云港市工业化与城市化互动发展的制约因素,为制定连云港市工业化与城市化良性互动发展策略提供依据。     

城市随迁老人的精神生活与社区融入

随迁老人是指与进城子女一起生活而户籍在农村的老年群体。本文在实地调查的基础上,从闲暇时间利用、社区活动参与、社区情感和心理认同等方面描述老人的精神生活状况,发现该群体精神生活单调、很少参与社区活动、对城市社区的认同度低。要改善随迁老人的精神生活,必须通过社区融入的方法,组织多样化的社区活动,扩大老年人社会交往的范围,帮助他们重新构建一个新的社交网络,从而改善他们的精神生活状态。     

老年人体育健身现状及策应研究——以南昌市D区为例

本文为了深入了解南昌市老年人体育健身的现状,进而提出科学、合理、切实可行的健身处方,特采用问卷调查法、数理统计法、逻辑分析法对南昌市D区老年人体育健身情况进行调查研究。结果显示:南昌市不同性别老年人参与体育健身的积极性都较高,健身内容与手段呈现多样化,健身活动场所相对固定,参与体育健身的目的较为明确。但是,在健身科学化上还存在不足,缺乏场地器材、缺乏时间、缺乏指导成为影响参与体育健身的最重要因素。     

湛江市高校学生瑜伽健身开展现状及影响因素分析

采用测量法、实验法与数理统计等方法,对湛江市高校学生瑜伽健身开展现状与影响因素进行调查,结果表明：①学生对瑜伽认识程度基本处于接触阶段;②女大学生参与瑜伽健身的积极性明显高于男生;③影响高校学生瑜伽健身活动开展的影响因素有：瑜伽指导员的水平、练习场地与音响设备的使用等.该研究可为促进广东省粤西地区大学生瑜伽健身开展和普及提供参考依据.     

试析城市社区老年人口需求状况——以长沙市天心区A社区为例

随着人口老龄化加快,有关老年人的问题逐渐成为全社会普遍关注的焦点问题。笔者运用实证研究方法,对长沙市天心区A社区老年人的生存需求、健康需求、精神需求等多项内容进行了调查和分析。     

Limits and challenges for the participation of migrants' associations in state development policies in Morocco and Mexico

In many developing countries, migrants play an important role by supporting their local communities in their places of origin. An extensive literature has made visible their contribution to local development, thus revealing their involvement in the provision of social services or the construction of infrastructures. In this paper we illustrate the extent and scope of this task and the types of actions that migrants have started up in different countries of the world in general, and the cases of Morocco and Mexico in particular, to examine the achievements and limitations of both states' policies and migrants' associations in regard to their involvement in local development initiatives.     

Gated Communities in Mexico City

ABSTRACT

Based on long-term field research, this article addresses the issue of gated communities in Mexico City as a specific form of the crisis of public space and urban order in a stratified society. By comparing different forms of “gated community,” the paper shows their common characteristics in spite of their morphologic differences. Living in segregated residential spaces in Mexico City is a complex social process which is not only the result of the fear of crime but also a way to escape from urban disorder, to set up islands of social homogeneity and to experiment with new forms of local government.