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1.
人工生物浮岛载体的研究进展   总被引:10,自引:0,他引:10  
为改善浮岛性能,减少有机高分子材料所造成的"白色污染",有必要研制开发新型浮岛载体-轻质高效微生物载体.从国内外浮岛的研究现状看,目前在工程实例中广泛采用的是有机高分子材料载体,无机材料的浮岛尚处于实验研究阶段.在对几种典型无机材料-轻质滤料的物理特性、成分、化学稳定性、价格、来源等方面进行综合分析后可知,用无机材料制作有机浮岛载体的替代品是可行的,具有广阔的发展前景,但还需进一步的研究和探索.  相似文献   
2.
黄河三角洲贝壳海岛与植物多样性保护   总被引:3,自引:0,他引:3  
根据1997-1999年调查,查清了黄河三角洲贝壳岛资源状况,研究了其高等植物物种多样性、植被类型、植物区系组成特点,分析了近年来因乱采滥挖贝壳资源对贝壳海岛和植物多样性破坏现状,提出了保护贝壳海岛和和植物多样性的对策与建议。  相似文献   
3.
Interannual changes in geobiont and chortobiont abundance on the islands of Kuibyshev Reservoir are largely determined by flood conditions, because the seasonal average abundance of many taxa is negatively correlated to the water level in May and June. Floods influence the abundance of these animals both directly and indirectly, through biocenotic connections and some aspects of behavior. Long-term positive trends are observed in the abundance of many species. The hypothesis is proposed that this increase in the abundance of geobionts and chortobionts is a consequence of adaptation processes in these communities, which are stimulated by the flood regime of the reservoir.  相似文献   
4.
Since the end of the 1970s, the southern European countries have shown an exceptional reduction in fertility rate. From the highest levels among the developed nations, these countries dropped beneath the substitution rate level: in Greece there is an average of about 1.5 children per woman, and Italy (starting three to four years ago), with 1.3 children per woman, is now the country with the lowest fecundity rate in the world. Land-use planning in southern European small islands therefore requires substantial revision. In the areas where western civilization began, which are highly populated and have a long history, cultural and ethnic aspects of tradition are fundamental to environmental management and to the defense of historical heritage. They also place a strong value on sustaining tourism, the most relevant economic activity, that allows them to survive and maintain a high welfare level. For some decades they have had populations with a marked presence of young people and high emigration rates, but now they are fast becoming dominated by the elderly and must prepare for a period of fast reduction in youth of the workforce, while the peripheral areas of Asia and Africa are entering a sudden demographic growth phase. The demographic structure has also been deeply altered both by previous migrations and by random variations, as usually happens in all small communities. Social services for younger and older people have had to be adapted rapidly, reorganizing high-school management, hospital and health-care structures, in-house assistance, and so on. There is a need to rethink the job market and favor the immigration of highly specialized workers, which is a necessity for technical evolution. Sustainable development is constrained nowadays not only by the scarcity of natural resources, but also by the quality and quantity of human resources. Proper policies for population and land-use planning are highly correlated factors; they have to be considered with respect of these new, rapid demographic changes.  相似文献   
5.
Several multicriteria evaluation techniques have been developed since the 1970s. The need to compare different territorial policies has justified their introduction into environmental research. These methods are based on the numerical manipulation of heterogeneous information, which varies in terms of reference scale and type of measure (continuous, ordinal, qualitative, binary, etc.). During recent years, diverse investigations have focused on general conditions on Salina, the “green island” of the Aeolian archipelago. Such studies, within an interdisciplinary project, aimed to explore the possibility of implementing conservation strategies that are compatible with human needs, landscape preservation, and sustainable economic development. Three different evaluation techniques are applied, namely multicriteria weighted concordance and discordance analysis and a qualitative procedure. They are used to compare four alternative plans for the socioeconomic development of Salina Island. These plans lie between extreme alternatives: total protection of natural resources and maximizing economic development based on tourism. The plans are compared to each other on the basis of 14 criteria that reflect the socioenvironmental perception of Salina's inhabitants. The approach used in this research seems particularly fruitful because of its flexibility: it offers decision makers the chance to manage heterogeneous data and information that is not easily quantifiable. Such “soft” information helps to evaluate environmental conditions more precisely, and to make a less damaging choice among alternative development plans.  相似文献   
6.
For about 50 years the desertion of areas by traditional activities has led to an important evolution of landscapes and environments on the island of Ouessant. The study of this evolution has been undertaken at different spatial and temporal scales. On one part of the island, a scientific investigation carried out at the scale of the parcel enabled the form of the landscape in 1850 to be compared with that of 1985. On the whole island, the evolution of spatial organization and land use was compared between 1950 and 1985. For each of three main ecological environments, vegetational successions after the decrease of agriculture have been studied along with their future potential changes. This work highlights some considerations about the present management of the environment in relation to the major objectives of island environmental policies.  相似文献   
7.
Abstract: Extinctions can leave species without mutualist partners and thus potentially reduce their fitness. In cases where non‐native species function as mutualists, mutualism disruption associated with species’ extinction may be mitigated. To assess the effectiveness of mutualist species with different origins, we conducted a meta‐analysis in which we compared the effectiveness of pollination and seed‐dispersal functions of native and non‐native vertebrates. We used data from 40 studies in which a total of 34 non‐native vertebrate mutualists in 20 geographic locations were examined. For each plant species, opportunistic non‐native vertebrate pollinators were generally less effective mutualists than native pollinators. When native mutualists had been extirpated, however, plant seed set and seedling performance appeared elevated in the presence of non‐native mutualists, although non‐native mutualists had a negative overall effect on seed germination. These results suggest native mutualists may not be easily replaced. In some systems researchers propose taxon substitution or the deliberate introduction of non‐native vertebrate mutualists to reestablish mutualist functions such as pollination and seed dispersal and to rescue native species from extinction. Our results also suggest that in places where all native mutualists are extinct, careful taxon substitution may benefit native plants at some life stages.  相似文献   
8.
基于国内外海洋生态环境质量综合评价方法,结合我国海洋生态环境调查数据,从环境和生物学要素中选取12个指标建立评价指标体系,确定5个评价等级及标准,采用层次分析法确定指标权重,构建我国海岛周边海域生态环境质量综合评价方法.选取南海北部10个代表性海岛,对其周边海域生态环境质量进行综合评价,结果表明:研究海岛中特呈岛和内伶仃岛评价等级为中,其余8个海岛均为良;离岸距离、陆源污染物排放量和海水交换能力直接影响评价结果.该方法能较好地反映海岛周边海域生态环境状况,可操作性强,可作为今后我国海岛周边海域生态环境质量评价的参考.  相似文献   
9.
海岛生态环境脆弱,保护海岛及其周边海域生态系统,合理开发利用海岛自然资源,促进海岛经济社会可持续发展是我国海岛保护法的根本宗旨。论文试图借鉴陆域可持续发展指标体系的思路,结合海岛的自然环境与社会经济特殊性,从生存支持、生态环境、经济发展、社会与智力支持四个层面选取指标,并将熵权法和非结构性决策模糊集理论模型相结合确定海岛可持续发展评价指标的权重,构建海岛可持续发展的指标体系;进一步引入可变模糊评价方法,建立基于可变模糊集理论的海岛可持续发展综合评价模型,对辽宁省长海县2001-2011年可持续发展的状况进行评价验证,识别影响长海县可持续发展能力的关键因素、存在的问题与限制性因子,为提高海岛经济社会可持续发展水平提供科学的分析数据。  相似文献   
10.
This paper assesses quantitatively the impact of sea level rise (SLR) at the global and regional scale as a result of climate change (CC) on the coastal areas of the Kingdom of Bahrain’s islands (36 Islands). The standard Intergovernmental Panel on Climate Change (IPCC) guidelines was modified as appropriate for the situation of the study area. Geographic Information Systems (GIS) coupled with Remote Sensing (RS) were used as the main techniques of collecting, analyzing, modeling simulating and disseminating information to build SLR scenarios in a geographically referenced context. Also, these tools were used to assess vulnerability and risk of the coastal area of the islands with the expectation that coastal planner and government authorities will profit from integrating these knowledge into a broad based environmental decision making. Three SLR scenarios: low, moderate and high were developed to examine the impacts from SLR on all islands. The low SLR scenario (Optimistic) assumes a 0.5-m rise above current sea level, the moderate scenario (Intermediate) assumes a one meter rise, and the high scenario (Pessimistic) assumes a 1.5 m rise in sea level. Two more SLR scenarios were assumed to perform risk analysis, a 2 and 5 meter rise above current sea level. The simulation of SLR are quite straightforward, emphasizing on the uses of both of the data that are incorporated from the satellite images and the created Digital Elevation Model (DEM) to estimate SLR scenarios that are adapted in the study. These data were used to predict consequences of the possibility of the rise in sea level at different scenarios which may alter the landuse and patterns of human communities. Results indicate that low-lying coastal areas of Bahrain islands are at risk from the effects of any SLR resulting from CC. These islands are vulnerable under different SLR Scenarios. More than 17% of the country total area may be inundated under 1.5 m SLR in 2100. The total area that might be lost under different sea level scenarios will vary from more than 77 km2 if SLR reaches 0.5 m, to about 100 km2 under 1.0 m SLR and may reach 124 km2 under 1.5 m SLR scenario. The total inundated areas due to risk scenarios will reach 133 km2, if the SLR rises to 2.0 m, and it is estimated to be more than (22%) of the main island total area. Under the second scenario, if the SLR reaches 5.0 m, the main islands will lose approximately half of its area (47%) equal to 280 km2. Hawar islands group will lose about (30%) of its total area under 2.0 m SLR, which is about 15.5 km2.A SLR adaptation policy framework (APF) and adaptation policy initiatives (APIs) are suggested for planners to build upon for reducing the likely effects of SLR in the Kingdom of Bahrain. The framework is composed of four steps namely, acquisition of information, planning and design, implementation and monitoring and evaluation. A general policy framework for a national response to SLR is suggested. Additionally, a range of policy adaptation options/initiatives to sustain coastal developments under the likely effects of SLR are recommended.  相似文献   
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