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1.
Spartina pectinata (prairie cordgrass) was grown under five hydroperiods (wet–dry cycles) to determine its potential for use in stormwater wetlands, particularly as an alternative to the highly invasive Phalaris arundinacea (an exotic grass). Rhizomes planted in outdoor microcosms grew vigorously in all treatments, namely, weekly flooding in early summer, weekly flooding in late summer, flooding every three weeks throughout the summer, weekly flooding throughout the summer, and no flooding. Neither the timing nor frequency of 24-hour floods (10–20 cm deep) affected total stem length (grand mean 1003 ± 188.8 cm per pot, n = 140) or above-ground biomass (46.5 ± 8.3 g per pot, equivalent to ∼360 g/m2). However, by late summer, fewer new tillers were found in unflooded microcosms, indicating that vegetative expansion is drought-sensitive. The growth of Spartina plants was further assessed with and without Glyceria striata (a native grass) and Phalaris arundinacea. Glyceria growth was not affected by hydrologic treatment. Glyceria reduced Spartina growth by approximately 11%, suggesting potential as a cover crop that might reduce establishment and growth of Phalaris seedlings. Seeds of Phalaris did not germinate, but branch fragments established where soil was moist from flooding, regardless of the presence of Glyceria. The ability of Spartina to establish vegetatively and grow well under variable water levels leads us to recommend further testing in stormwater wetlands, along with early planting of Glyceria to reduce weed invasions.  相似文献   

2.
生物入侵中入侵种与土著种的相互作用   总被引:3,自引:0,他引:3  
李冰  李玉瑛 《四川环境》2009,28(1):64-67
在全球范围内,生物入侵已经成为一个非常严重的环境问题,并产生了生态问题和经济问题。本文阐述了生物入侵中入侵种自身的变化及对土著种的影响,并讨论了生物入侵过程中入侵种与土著种的快速进化问题。  相似文献   

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Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221–279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners’ behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.  相似文献   

5.
Honeybee colonies are declining in some parts of the world. This may have important consequences for the pollination of crops and native plant species. In Spain, as in other parts of Europe, land abandonment has led to a decrease in the number of non professional beekeepers, which aggravates the problem of honeybee decline as a result of bee diseases In this study, we investigated the effects of honeybees on the pollination of three native plant species in northern Spain, namely wildcherry Prunus avium L., hawthorn Crataegus monogyna Jacq., and bilberry Vaccinium myrtillus L. We quantified fruit set of individuals from the target species along transects established from an apiary outwards. Half the samples were bagged in a nylon mesh to avoid insect pollination. Mixed-effects models were used to test the effect of distance to the apiary on fruit set in non-bagged samples. The results showed a negative significant effect of distance from the apiary on fruit set for hawthorn and bilberry, but no significant effects were detected for wildcherry. This suggests that the use of honeybees under traditional farming practices might be a good instrument to increase fruit production of some native plants. This may have important consequences for wildlife conservation, since fruits, and bilberries in particular, constitute an important feeding resource for endangered species, such as the brown bear Ursus arctos L. or the capercaillie Tetrao urogallus cantabricus L.  相似文献   

6.
Environmental Management - In the past decade, municipalities across North America have increased investment in their urban forests in an effort to maintain and enhance the numerous benefits...  相似文献   

7.
Impacts of human land use pose an increasing threat to global biodiversity. Resource managers must respond rapidly to this threat by assessing existing natural areas and prioritizing conservation actions across multiple spatial scales. Plant species richness is a useful measure of biodiversity but typically can only be evaluated on small portions of a given landscape. Modeling relationships between spatial heterogeneity and species richness may allow conservation planners to make predictions of species richness patterns within unsampled areas. We utilized a combination of field data, remotely sensed data, and landscape pattern metrics to develop models of native and exotic plant species richness at two spatial extents (60- and 120-m windows) and at four ecological levels for northwestern Ohio’s Oak Openings region. Multiple regression models explained 37–77 % of the variation in plant species richness. These models consistently explained more variation in exotic richness than in native richness. Exotic richness was better explained at the 120-m extent while native richness was better explained at the 60-m extent. Land cover composition of the surrounding landscape was an important component of all models. We found that percentage of human-modified land cover (negatively correlated with native richness and positively correlated with exotic richness) was a particularly useful predictor of plant species richness and that human-caused disturbances exert a strong influence on species richness patterns within a mixed-disturbance oak savanna landscape. Our results emphasize the importance of using a multi-scale approach to examine the complex relationships between spatial heterogeneity and plant species richness.  相似文献   

8.
Urban Domestic Gardens (XIV): The Characteristics of Gardens in Five Cities   总被引:1,自引:0,他引:1  
Domestic gardens make substantial contributions to the provision of green space in urban areas. However, the ecological functions provided by such gardens depend critically on their configuration and composition. Here, we present the first detailed analysis of variation in the composition of urban gardens, in relation to housing characteristics and the nature of the surrounding landscape, across different cities in the United Kingdom. In all five cities studied (Belfast, Cardiff, Edinburgh, Leicester, and Oxford), garden size had an overwhelming influence on garden composition. Larger gardens supported more of the land-use types recorded, in greater extents, and were more likely to contain particular features, including tall trees and mature shrubs, areas of unmown grass and uncultivated land, vegetable patches, ponds, and composting sites. The proportional contribution of non-vegetated land-uses decreased as garden area increased. House age was less significant in determining the land-use within gardens, although older houses, which were more likely to be found further from the urban edge of the city, contained fewer hedges and greater areas of vegetation canopy >2 m in height. Current UK government planning recommendations will ultimately reduce the area of individual gardens and are thus predicted to result in fewer tall trees and, in particular, less vegetation canopy >2 m. This might be detrimental from ecological, aesthetic, social, and economic stand points.  相似文献   

9.
王永刚 《环境教育》2004,(11):78-78
环境保护的希望和未来在哪里?在学校,在孩子。为使孩子从小接受环境教育,从小了解我国环境污染的严重性和污染治理的紧迫性,本刊自本期起,特设“环境前沿”专栏,采用栏目主持的方式,向广大读者提供环境问题和污染治理的前沿报告。以期促进全国环保工作的开展和全国公众环境意识的提高。  相似文献   

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李强  刘宏立  郑坚 《四川环境》2007,26(2):23-25,48
对城市园林绿地生态环境效应的分析表明,城市园林绿地是城市生态系统的重要组成部分,在维持城市生态平衡和改善城市生态环境方面起着其他基础设施所无法替代的作用。  相似文献   

12.
Rice (Oryza sativa L.) plants were cultivated in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, straw, and root. The contents of iodine in these components and the soil were determined by inductively coupled plasma-mass spectrometry and radiochemical neutron activation analysis, respectively. Iodine content varied by more than three orders of magnitude among the plant components. Mean concentration of iodine in the entire plants was 20 mg kg(-1) dry weight, and the concentration of iodine in the surface soil (0-20 cm depth) was 48 mg kg(-1). The highest concentration of iodine (53 mg kg(-1) dry weight) was measured in root and the lowest concentration (0.034 mg kg(-1) dry weight) in polished rice. While the edible component (polished rice) accounted for 32% of the total dry weight, it contained only 0.055% of iodine found in the entire rice plants. Atmospheric gaseous iodine (5.9 ng m(-3)) was estimated to contribute <0.2% of the total iodine content in the biomass of rice plants; therefore nearly all of the iodine in the rice plants was a result of the uptake of iodine from the soil. The content of iodine in the aboveground part of rice plants was 16 mg kg(-1) dry weight and the percentage of iodine transferred per cropping from the soil into the aboveground biomass corresponded to 0.27% (20 mg m(-2)) of the upper soil layer content.  相似文献   

13.
邱秋 《中国环保产业》2002,(7):46-47,48
本文分析了我国绿色包装的发展现状和面临的困境,提出必须从环境保护、循环经济、绿色市场和技术进步等方面推动绿色包装,实现包装业可持续发展。  相似文献   

14.
强化管理促进清洁生产发展   总被引:1,自引:0,他引:1  
阐述了促进清洁生产的途径、手段和应动员全社会起来促进清洁生产。  相似文献   

15.
用CdCl2将盆栽土壤Cd浓度处理为1mg/kg、5mg/kg、10mg/kg、20mg,/kg、30mg/kg种植棉花,研究棉花对镉的吸收及镉在棉花体内的分布规律。结果表明,当土壤镉浓度小于30mg/kg时,镉在棉花体内的分布呈现不同的规律。当土壤镉浓度小于5mg/kg时,镉主要分布在棉花的地上部;当土壤镉浓度大于20mg/kg时,镉主要分布在棉花的叶片、根、茎中,其中叶片的镉含量最高,棉絮镉含量最低。不同镉污染水平下,棉花的镉富集系数均小于1。当土壤镉污染浓度为5mg/kg时,棉花叶片的镉富集系数为0.76。在同一镉污染水平下,棉花叶片的镉转运系数最高。当土壤镉含量小于20mg/kg时,棉花茎、叶、棉絮的转运系数平均为4.63。  相似文献   

16.
天然水蛭和水蛭素的开发利用   总被引:1,自引:0,他引:1  
水蛭素是高效特异性凝血酶抑制剂,是正在开发的抗疑、抗血栓新药;水蛭则是传统中药,具有消肿、去瘀等功效.本文探讨了从水蛭中制取水蛭素的方法与意义,为四川水蛭和水蛭素的开发利用提供了依据.  相似文献   

17.
Reflecting a worldwide trend of devolution of power and responsibilities to local authorities, metropolitan local governments in Australia now have a role in protecting and managing native vegetation (bushland). Reporting on questionnaire and interview results for Sydney, Melbourne, Perth, and Adelaide, this research examines the main disturbances in local government bushlands, local governments efforts in bushland conservation, and universality of issues and responses among the cities and between urban and urban–rural local authorities. A number of disturbances in bushlands are common among the cities, with weeds, development impacts, and urban run off perceived to be the most threatening. Management efforts focus on weed control, whereas other main disturbances are receiving less attention. Community involvement in management is prevalent, although regional coordination among local governments is limited. Local governments are willing to be involved in biodiversity conservation and their capacity would be enhanced with increased funding, staffing, and regional coordination.Published online Note: This version was published online in June 2005 with the cover date of August 2004.  相似文献   

18.
For the last 20 years, human–wildlife conflicts have been rapidly increasing in towns. Although people want “greener” cities, the expansion of disliked species causes problems that are difficult to manage and to reduce. The complexity of the numerous factors involved in these human–wildlife relations needs the development of a comprehensive tool for urban planners. Today, with the development of computers and geographical information systems, it is easier to analyze and combine different spatial data as methods used for the management of risks in studies of natural hazards. Here we present a method for assessing and mapping the risk in cases of human–wildlife conflict. An application to starling management in a town in western France will show the efficiency of our methods to combine information given by a network of experts and to highlight higher risk sites. The map of risk provides a spatial result useful for comprehension, communication between people and agencies, and public education.  相似文献   

19.
从分析房车旅游概念和特征人手,结合国内外房车旅游发展现状,运用SWOT分析法对海南房车旅游业的发展进行了分析.在此基础上,对海南发展房车旅游提出四点对策建议:①建立“政府引导、行业合作、企业创新”的房车旅游管理和运行机制;②抓住目标消费市场,加强多元化营销,更新传统消费理念;③积极借鉴国际房车旅游发展经验,以国际化改造为手段,建立衔接国际标准的房车旅游服务体系;④完善信息网络基础设施,推进房车旅游信息系统建设,发展海南智慧旅游.  相似文献   

20.
通过分析循环经济在国内外发展的基本状况,提出了株洲市要大力推进和发展循环经济以缓解资源约束矛盾、提高企业效益和从根本上减轻环境污染。  相似文献   

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