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1.
To estimate the impacts of invasive plants on ecosystems, a survey has been conducted in three sites including both buffer zones and core zones. 13, 19 species are found in the Yuntai Mountain and Longchi Mountain natural reserve respectively, and 23 in the Purple Mountain Natural Park. Altogether 25 species belonging to 12 families, the majority of which are native to North America, some of them have set up stable reproducible populations. Among them, Solidago canadensis is found in Longchi Mountain and Purple Mountain. Communities of Galinsoga parviflora, Gynura crepidioides, Ageratum conyzoides, and Ambrosia artemisiifolia pose a serious threat to local biodiversity.  相似文献   

2.
开发区是全球化时代出现的新产业空间。开发区在我国经济发展和改革开放中,发挥了重要作用。理论界将我国开发区发展阶段总结为一次创业和二次创业两个阶段,但是目前我国开发区普遍出现了从工业园向新城区转型的趋向。从企业家型城市的理论视角,通过对苏州工业园发展与转型的实证研究,论证开发区建设进入第三次创业的新阶段———即从工业园向城市新区的转变。在新一轮转型中,苏州工业园实施了企业家的城市策略,采取了园区再定位、创造新城市空间等企业家城市行动,园区的新城功能和第三产业得到迅速发展。同时,研究也发现园区管委会的管治体系发生了根本变化,从促进经济增长管理向社会和城市综合管理转型。该研究将对我国新一轮开发区的转型具有重要启示。  相似文献   

3.
开发区是全球化时代出现的新产业空间。开发区在我国经济发展和改革开放中,发挥了重要作用。理论界将我国开发区发展阶段总结为“一次创业”和“二次创业”两个阶段,但是目前我国开发区普遍出现了从工业园向新城区转型的趋向。从企业家型城市的理论视角,通过对苏州工业园发展与转型的实证研究,论证开发区建设进入“第三次创业”的新阶段——即从工业园向城市新区的转变。在新一轮转型中,苏州工业园实施了企业家的城市策略,采取了园区再定位、创造新城市空间等企业家城市行动,园区的新城功能和第三产业得到迅速发展。同时,研究也发现园区管委会的管治体系发生了根本变化,从促进经济增长管理向社会和城市综合管理转型。该研究将对我国新一轮开发区的转型具有重要启示  相似文献   

4.
公园绿地是城市公共服务设施的重要组成部分,其空间布局与城市居民生活息息相关。根据布局现状,以2020年为优化时间结点,兼顾布局效率和布局均衡,首先以居民出行成本最小化为效率性目标,构建选址模型以对新增公园绿地进行选址;再以可达性差异最小化为均衡性目标,构建面积优化模型以确定公园绿地的合适规模。两种模型共同实现了公园绿地的布局优化。研究表明:(1)现状条件下,公园绿地布局不能满足居民的基本游憩需求,空间效率性和均衡性较低;(2)要实现本文的优化目标,需新增全市性公园绿地28座,共计1 100 hm2;需新增区域性公园绿地34座,共计868. 01 hm2;(3)区位选址模型显著降低了居民到达公园绿地的出行成本,人均出行成本由1 311. 24 m降低到了915. 93 m;(4)区位选址和规模优化模型能够显著提高公园绿地布局的均衡性,使得公园绿地布局与居民人口比配达到均衡,居民至整体公园绿地可达性差异系数由0. 71降低到了0. 54。  相似文献   

5.
In this study, we investigate whether traditional swidden agriculture on nutrient-poor tropical soils can sustainably support a growing indigenous population within Manu National Park, Peru. Based on interviews with 50 Matsigenka farmers, as well as GPS mapping and field visits, we established the location and size of all 124 swidden gardens cultivated in 2000 and 2001. Using a GIS-based soil map of Manu Park, we identify the total extent of potential arable land (1) throughout the park zones currently available for Matsigenka habitation, and (2) within the vicinity of the two study communities. Taking into account current per capita garden size, cultivation and fallow practices, we calculate the maximum human carrying capacity of swidden agriculture for (1) all available park zones and (2) the immediate vicinity of the two current communities. Even given the second, highly limited scenario, the sustainable human carrying capacity is estimated to be 2,138 individuals, which is far higher than the current population of about 420 people. Thus, arable land does not appear to be a limiting factor for the growth of the indigenous population in Manu Park at the current time. Other possible limiting factors for population growth are identified and discussed. We conclude that a conservation policy of population stabilization around the current settlements is viable in that it will not result in reduced resource availability over the next few decades, and that the challenge is to identify and mitigate the forces causing population fissioning and spread. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

6.
A method for estimating the current state of plant communities based on the ecological amplitudes of constituent species is proposed. An original program, Fitoindikatsiya, has been developed to compute the indices of disturbance and homogeneity of plant communities from species ecological scale values. The current state of pine forests in the part of Novosibirsk oblast east of the Ob River has been analyzed; slightly, moderately, and severely disturbed zones have been distinguished.  相似文献   

7.
Characteristics of the adaptive response of the female generative system of Scotch pine to air pollution caused by petroleum gas burning in flares during oil production in Western Siberia have been studied. The relationship between the individual and endogenous variations of the quantitative parameters of pine cone morphology has been analyzed in different zones of deterioration.  相似文献   

8.

In the past decade, Doha has witnessed fast-urban growth, an increased population rate, and an over-reliance on the automobile as the main mode of urban transportation. These factors caused social and environmental problems related to (1) the loss of a compact urban pattern, (2) an increased level of air pollution (3) high traffic congestions and (4) increasing landscape fragmentation. In consideration of such concerns, The State of Qatar invested large funds into the urban landscape development of Doha, as envisioned by Qatar National Vision 2030. As a result, in the past five years various parks and/or green areas, such MIA Park, a major public green space located around the Museum of Islamic Art (MIA), were planned and developed within metropolitan Doha. The authors argue that this park is currently facing issues and challenges related to (1) accessibility to/from the neighboring districts, and (2) connectivity to/from the neighboring parks. Therefore, this research study aims at assessing the existing conditions of MIA Park, at considering the broader city context and, at recommending strategies for implementing MIA Park’s green network system. It approached the investigative challenge using a multi-pronged comprehensive methodology, that deployed focus groups, semi-structured interviews and a comprehensive network analysis based on graph theory. The findings, revealed through these hybrid research tactics, allowed the researchers to generate a framework to enhance accessibility and connectivity of MIA Park through a green network system, planned at inter-related neighborhood-scale and city-scale levels. While the research examines most notably a single case, it is advocated that the proposed framework represents not just an optional feature pertaining to the case in Doha, but a valuable reference for the sustainable master planning of future cities in the State of Qatar and across the GCC. The paper proffers numerous key contributions, including the critical exploration of manufactured landscapes in Doha Qatar and the delineation of broadly applicable environmental design strategies to improve the fabric and livability of cities.

  相似文献   

9.
A census of spiders has been taken in Moscow oblast and Krasnodar krai (the Kuban Plain) in fields under corn, vetch-oat mixture, and winter wheat (in the central and peripheral zones separately), as well as on their margins and in adjoinint areas of other biotopes. Spiders were collected using entomological sweeping and pitfall traps. On the whole, 286 species of 20 families and 146 genera have been found (205 species in Moscow oblast and 139 species in Krasnodar krai). The level of species diversity does not change significantly; a noticeable decrease in this parameter is observed only in the central zones of fields. In Moscow oblast, species diversity reaches a peak at field margins; in Krasnodar krai, no regular differences in this parameter between the forest strip, field margin, and the peripheral zone of a crop field has been revealed. Species diversity usually decreases toward the field center. However, changes in species diversity at a distance of more than 100 m from the margins are insignificant.  相似文献   

10.
The current state of Mediterranean mountain areas has been driven by two main factors: intense traditional human activity and the dynamics of the ecosystem itself. In this study, we examine land-cover changes in a National Park in the Pyrenees mountains (NE Iberian Peninsula), which was designated a protected area 55 years ago. First, we have analyzed spatio-temporal changes in land-cover pattern and forest dynamics from 1957 to 2005. During this period, land-cover dynamics consisted of two main processes: (i) expansion of the forest area and (ii) increasing cover of forests already present in 1957. To analyze the role of the conservation level of the park, we have also compared the results obtained within the park with those of unprotected, peripheral areas. In the two areas with different protection level, dense forests increased throughout the period because of the reduction in forestry activities. The peripheral area showed a higher rate of forest-cover change from 1957 to 2005 compared to the National Park. This higher increase in forest cover in the peripheral area could be related to a higher proportion in the National Park of screes and rocky areas and to the decline and transformation of forest activities in these peripheral, lower elevation areas.  相似文献   

11.
Morphometric characteristics of the growth of forest stands located at different distances from a large copper-smelting plant were estimated. The set of diagnostic parameters obtained was used for calculating summary parameters of the state (SPSs) of the forest stands and to grade their values for zoning the forests. The results of using semivariance analysis demonstrated the appropriateness of kriging, a method of spatial interpolation, for mapping the surfaces of the state of forests. The map-scheme of the zones differing in the state of forest stands (made on the basis of summary parameters) was compared with the topographic map of the area, which made it possible to estimate the effect of large forms of relief on the location and configuration of the zones.  相似文献   

12.
Changes in parameters of species richness and dominance in parasite communities of perch have been analyzed in the age series of hosts from two water bodies, Lake Gusinoe and Chivyrkui Bay (Lake Baikal), at the levels of a host individual (infracommunity) and a host age group (set of infracommunities). The species richness of parasite infracommunities has been found to increase in both age series due to decreasing proportions of fish affected by no more than three to four parasite species and increasing proportion of fish parasitized by more than four to five species.  相似文献   

13.
14.
城市绿化屋顶的微气候调节与径流削减效应研究   总被引:1,自引:0,他引:1  
快速城市化与气候变化双重作用下,热岛效应与城市内涝成为最为突出的城市环境问题。绿化屋顶因能有效利用闲置屋面添緑、帮助城市缓解热岛和暴雨径流而受到关注。以往研究较多探讨单种气象条件下、单个小面积实验型绿化屋面的气候水文调节功能,本研究基于夏秋两季的微气候水文观测数据,定量分析不同气象条件下5种典型绿化屋顶的降温和径流削减效应。首先选择晴朗、多云、降雨3种典型夏日天气条件,分析草坪、裸土、菜地、小面积花园、大面积花园5种类型绿化屋顶与对照光屋顶之间的温度差日变化规律,探讨绿化屋顶热效应强度及时空特征;其次,选择暴雨、大雨、中雨及小雨4次典型降雨,分析大面积草坪与花园型绿化屋顶上的降雨-滞蓄过程及径流削减率。研究结果表明:绿化屋顶降温与升温效应并存,晴朗无风天气条件下,距离屋面10 cm和150 cm两个高度上,绿化屋顶最高可降低气温5.3℃和2.5℃,多云及降雨天气条件下降温强度下降,升温时段延长;白天草坪与裸土上的大气温度高于对照光屋顶,其它绿化屋顶的温度低于对照屋顶;夜间5个绿化屋顶的大气温度均低于对照屋顶,且降温效应按照大面积花园、草坪、小面积花园、裸土、菜地的顺序递减。绿化屋顶径流削减效益与绿化类型及降雨强度密切相关,花园型绿化对一次典型暴雨、大雨、中雨、小雨的径流削减率分别为50.8%、78%、100%、100%,简易型绿化的4次径流削减率分别为24.3%,58.6%,98.2%和100%。研究结果可为同气候区其他城市绿化屋顶环境设计及管理提供一定参考价值。  相似文献   

15.
Changes in the species composition and a decrease in species diversity and total plant biomass along the gradient of soil pollution with heavy metals have been shown. Data on the concentrations of chemical elements (Zn, Cu, Cd, Pb, Co, Ni, Mn, Cr, and Fe) in the aboveground organs of herbaceous plants and the biomass of each species make it possible to estimate the role of higher producers in the incorporation of chemical elements into biogenic cycles in background zones and under conditions of chemical pollution. Plants of the composite family (Asteraceae) play the main role in accumulation of chemical elements. The results obtained indicate that natural ecosystems have mechanisms limiting excessive accumulation of chemical elements into the aboveground plant biomass.  相似文献   

16.
On the basis of studies on the ecology of boreal bat species in the Southern Urals (1997–2004), the first classification of their summer habitats has been made. It has been shown that spatial segregation of sex groups into areas of two types, designated wintering and breeding zones, takes place in populations in the period of offspring rearing. In females, seasonal migrations are guided by imprinting on sites providing sufficient food for offspring rearing and on wintering sites. In males, imprinting on wintering sites alone is observed.  相似文献   

17.
Corridors (variably called landscape linkages, connectors, and gateways) are expanses of a landscape that facilitate the flow or movement of individuals, genes, and ecological processes. Protected areas with their buffer zones and the corridors that connect them are cornerstones of modern conservation actions to maintain the biodiversity we have and restore what we have lost. Policy and governance to guide the establishment and management of protected areas and supporting buffer zones is well established in the Central Indian Highlands. A policy and governance structure to create the context and enabling conditions for corridor maintenance, creation, and recovery is emerging but is constrained by the reigning land-management paradigm that separates conservation from development rather than mainstreaming species and habitat conservation into the rural development agenda. Well-nourished, healthy human populations and healthy ecosystems are inextricably linked. The worsening ecological conditions in the Central Indian Highlands can trigger the emergence of a common agenda for an inclusive, caring, and environment-friendly mode of development. The alternative is the business-as-usual scenario: a continuation of worsening ecological conditions. Entry points through the biodiversity, agriculture production, resource extraction, and economic/social sectors to enable integrated sustainable landscape management are identified. These include deepening what it means to successfully conserve a species combined with explicit threat analysis for at-risk tigers and the landscapes that supports them; landscape scenario modeling to advance communication by synthesizing diverse forms of research and articulating and evaluating alternative socio-economic futures; and the use of the smart green infrastructure process as an approach to development rather than only as a way to mitigate environmental damage. Models are presented to scale up from isolated conservation interventions to collective impact that unites supportive government partners with individuals, NGOs, and economic interests to achieve viable long-term relationships in human and natural systems to value, maintain, and recover landscape connectivity.  相似文献   

18.
以无锡市区5个省级开发区为研究对象,基于抽样调查资料,从土地利用结构、土地利用强度和投入产出等方面分析了无锡市区省级开发区土地利用现状,对不同行业土地集约利用状况进行了定量评价。结果显示:电气机械及器材制造业土地集约利用水平较高,在08以上;交通运输设备制造业、通用设备制造业和通信设备、计算机及其他电子设备制造业的土地集约利用水平在075以上;橡胶制品业的综合集约度在07以上;其次是专用设备制造业和仪器仪表及文化、办公用机械制造业,为06以上;塑料制品业、金属制品业、纺织业和化学原料及化学制品制造业的土地集约利用水平相对较低,不到06。要合理控制开发区规模,不断提高开发区的经济效益;对新进项目设置明确的入园门槛,加大开发区内部的空间挖潜力度;完善土地利用的管理机制,严格开发区内工业用地的招拍挂出让制度。建立集约用地的考核制度,加强对集约用地的监督  相似文献   

19.
Analysis has been made of changes in the species composition and abundance of epiphytic lichens on fir trees during the first decade after a sharp reduction of emissions from a large copper smelter in the Middle Urals. The results show that lichens have recolonized the area of the former lichen desert and that the abundance of lichen species in the impact and buffer zones has increased. However, a fairly long time is required before lichen communities in the vicinity of the smelter can recover to the background state, since species highly sensitive to pollution still occur only in the background area.  相似文献   

20.
近2年国家批准了20个国家发展战略经济区.在这些地区,随各自自然环境的变化其自然灾害风险有所不同.该文基于对国家战略发展区域的历史(1949-2009年)灾情调查统计,构建了以人均损失、地均损失、损失占GDP的比重及人均GDP、地均GDP等5个指标为主的自然灾害风险评价体系.研究结果表明:天津市滨海新区、上海浦东新区为低度风险区;深圳市综合配套改革试验区、珠江三角洲地区、长江三角洲地区、辽宁沿海经济带、江苏沿海地区、沈阳经济区、武汉城市圈、黄河三角洲高效生态经济区为中度风险区;关中-天水经济区、海峡西岸经济区、广西北部湾、中部地区、长吉图开发开放先导区、海南国际旅游岛综合试验区为较高度风险区;成渝统筹城乡发展综合配套改革试验区、甘肃省、长株潭城市群、鄱阳湖生态经济区为高度风险区.该文针对各区域自然灾害风险特点提出了发展对策.  相似文献   

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