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1.
介绍了四川省丰富的野生观赏植物资源,分析了开发前景,针对其开发程度低、开发利用方式落后、资源保护性差的现状,指出四川省在野生观赏植物的保护和开发利用中应重点加强的几方面工作.  相似文献   

2.
庐山植物资源丰富.记述了庐山野生木本观赏植物的5个主要类别和4个观赏特性,充分认识和合理利用这些各具特色的野生木本观赏植物资源,在庐山生态旅游及城市建设中具有重要意义.  相似文献   

3.
安徽省黄山市蔷薇科野生木本观赏植物资源丰富,约有26属113种,其中悬钩子属25种,单属种9个,除具有观赏价值外,还具有药用价值、食用价值及其它用途,对黄山市蔷薇科野生木本观赏植物资源的综合开发利用和保护提出了建议。  相似文献   

4.
贵州山区是我国一个植物多样性较丰富的地区,仅野生观赏植物(含园林及行道绿化,美化树种)就有300多种,其中120多种属珍稀受危观赏物种。文章着重对36种主要珍稀濒危观赏植物的分布、生境、濒危类型、程度等进行了分析,并从观赏植物本身的生理生态习性、贵州山区生境本底的严酷性(土壤瘠薄,可有效利用的地表水匮乏等)、人类不合理干扰活动(如过渡采收、毁林垦荒等)方面探讨了该地区观赏植物多样性的受危原因。在此基础上,结合目前西部大开发中生态建设的要求,提出了该地区受危观赏植物的保护对策。  相似文献   

5.
峨眉山为中外驰名的风景名胜区,自然条件独特多样,为各种植物的生存与发展提供了良好条件,但迄今为止,尚未见有关野生观赏植物资源及其特点的专题报导。近20年来随着旅游业的蓬勃发展,峨眉山野生观赏植物作为重要景观资源的地位日益突出,但其中不少珍稀资源种类正受到严重的威胁,亟待抢救和保护。本文在调查结果的基础上,结合近年来的研究进展,对当地野生观赏植物资源状况进行了初步分析和研究。1资源环境背景峨眉山位于青藏高原外围,四川盆地西南边缘,东经103°29′,北纬29°30′,从山脚到山顶海拔垂直高程为550~3099m,山体…  相似文献   

6.
柃属为常绿灌木或小乔木,雌雄异株,花瓣呈黄、绿、白色,虫媒花,浆果黑色,是一类极具开发潜力的园林观赏植物。详述了华东地区分布的柃属植物资源种类,编制了简易的分种检索表,并对其观赏特性及园林用途进行了简述。  相似文献   

7.
魏振铎 《青海环境》2013,23(2):61-66,72
本文简述了观赏植物的定义问题、青海野生观赏植物的总体特征以及地域差异,列举了一些标志性群落和标志种,可能有益于今后的研究。  相似文献   

8.
河南太行山区地形复杂,山势陡峭,多悬崖峭壁和深陡峡谷,土层瘠薄,基岩裸露。该区独特的地理条件和复杂的气候变化,形成了太行山丰富的野生植物资源。现有蔷薇科野生树木资源15属、58种、6变种,具有较高的应用价值。1应用价值11园林应用价值园林应用价值主...  相似文献   

9.
宁夏具有丰富的野生经济植物资源,根据《宁夏野生经济植物》的记载,主要野生经济植物630种(包括亚种、变种和变型),按主要经济用途可分为药用植物、油料植物、淀粉植物、纤维植物、饲料植物、蜜源植物、芳香植物、栲胶植物、防污植物、野生果树、观赏植物、固沙植物等[1,2]。目前,宁夏野生经济植物数据库信息系统已研究成功并部分建立。研究和建立宁夏野生经济植物数据库信息系统的主要目的是利用微机的信息处理功能,快速、方便地检索和查询有关经济植物的基本信息(如分类名称、形态描述、地理分布、生境条件、理化性质等)…  相似文献   

10.
野外考察和文献调查分析表明,安徽省休宁县野生木质藤本植物资源丰富、种类繁多,累计有25科48属132种(含种以下等级),其中主要有葡萄科、蔷薇科、猕猴桃科、毛茛科、卫矛科、豆科等6个科.对藤本植物的观赏特性及园林用途进行了较详细的阐述.  相似文献   

11.
Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.  相似文献   

12.
ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.  相似文献   

13.
In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.  相似文献   

14.
Urban ecological systems: scientific foundations and a decade of progress   总被引:9,自引:0,他引:9  
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.  相似文献   

15.
All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.  相似文献   

16.
Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.  相似文献   

17.
Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.  相似文献   

18.
Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.  相似文献   

19.
Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.  相似文献   

20.
Biodegradation of [A‐ring 14C] Estrone (E1), 17β‐estradiol (E2), and 17α‐ethinylestradiol (EE2) to 14CO2 was investigated under light and dark conditions in microcosms containing epilithon or sediment collected from Boulder Creek, Colorado. Mineralization of the estrogen A‐ring was observed in all sediment treatments, but not epilithon treatments. No difference in net mineralization between light and dark treatments was observed for 14C‐E2. Net mineralization of 14C‐E1 and 14C‐EE2 was enhanced in light treatments. Extents of 14CO2 accumulation and rates of mineralization were significantly greater for E2 than E1 under dark conditions, but were comparable under light conditions. These results indicate substantial differences in the uptake and metabolism of E1 and E2 in the environment and suggest biorecalcitrance of E1 relative to E2 in light‐limited environments. The extent of 14CO2 accumulation and rate of mineralization for EE2 in dark treatments were less than half of that observed for E2 and generally lower than for E1, consistent with previous reports of EE2 biorecalcitrance. However, 14CO2 accumulation and rates of mineralization were comparable for EE2, E2, and E1 under light conditions. These results indicate photoactivation and/or phototransformation/photodegradation processes can substantially enhance heterotrophic biodegradation of estrogens in sunlit environments and may play an important role in estrogen transport and attenuation.  相似文献   

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