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1.
广西野生荔枝资源的研究价值及其保护对策   总被引:7,自引:0,他引:7  
针对野生荔枝在广西的分布现状,结合荔枝优稀种质鉴定研究,论述了广西野生荔枝资源遗传多样性及其在育种应用上的科研价值,并就目前对广西野生荔枝资源保护利用的紧迫性,提出了开展全面普查、建立种质保存圃和原位保护区、加强种质创新应用的几点对策意见.  相似文献   

2.
论述了安徽省黄山市分布的百合科野生药用植物的种质资源、地理分布、药用部位,为进一步开发利用提供依据。  相似文献   

3.
植物种质资源是人类赖以生存的资源,是一个国家和地区重要的基础性战略物质,四川植物种质资源无论是种类还是数量在全国都居重要地位。在分析四川种质资源特点和利用现状的基础上,对积极开展四川种质资源保护利用进行了探索和研究,提出了大力开展植物种质资源及其保存和利用现状的全面调查,摸清家底,逐步建立植物种质资源保护利用数据库和网络信息平台,大力开展多种形式的示范工程建设,积极开展植物种质资源监测网络建设,加强植物种质资源的研究开发,加强植物种质资源管理运行机制建设,搭建种质资源共享平台,加强人才队伍建设等植物资源保护和可持续利用对策及其保障措施。  相似文献   

4.
雅鲁藏布江大拐弯地区野果类资源初探   总被引:2,自引:1,他引:2  
本文通过对雅鲁藏布江大拐弯地区的考察.基本摸清了该地区野生果类资源的种类及分布状况,发现了1000年树龄的野生果树.以及可供科研和开发利甲的种质资源.同时.从考古资料的研究和考察中发现西藏是多种果肉的原产地,也是天然的果树种质资源库.  相似文献   

5.
为探讨渝产栀子的产业化发展思路和对策,采用到产地进行资源分布情况、种质资源类型、开发利用现状等多方面调查的方法,并对收集到的全国不同产地的20余份栀子商品药材进行了鉴定分析,总结了渝产栀子药材生产中存在的问题.对比四川、湖南和江西等地区栀子药材的种植、开发现况,结合现代药理研究成果和市场需求,分析了渝产栀子开发利用的前景和方向,为渝产栀子高附加值的深入开发提供参考.  相似文献   

6.
金荞麦(Fagopyrum dibotrys(D.Don.) Hara.)是我国民间的一种传统中草药,野生种质资源丰富,目前尚未进行大规模栽培生产.随着近年来金荞麦资源量的迅速减少,有必要对金荞麦的种质资源、地理分布、生态环境等重新进行实地调查研究,为其保护利用提供理论基础和科学依据.  相似文献   

7.
1993~1994年我们考察并初步鉴定了川西南的盐边,金阳等13个县大蒜种质资源,共收集38份资源样本,表示蒜头大,品质优,但当地利用差,与我国大蒜生产区之一的成都平原上的主要栽品种相比,选出了5个优异大种质资源,建议作主国商品大蒜头和早蒜苔生产的优异品种进行开发利用。  相似文献   

8.
古树作为一种重要的风景资源和珍贵稀有的植物资源,不仅富有极高的观赏价值,而且是研究植物区系的起源、演化和森林植被历史变迁的“活古董”以及研究古气候、古地理等方面的重要实物佐证。近年来由于各地盲目开发利用和乱砍滥伐,导致不少植物种质资源(特别是古老珍稀的种类)遭受破坏而濒临灭绝。因此,对古树进行深入调查研究和开展保护工作,具有重要的现实意义和社会经济意义。自然资源保护事业应该引起有关方面足够的重视,成为我国经济建设的一个不可分割的组成部分。  相似文献   

9.
四川省野生乌头资源调查研究   总被引:2,自引:0,他引:2  
调查四川省野生乌头资源的分布、生态环境及蕴藏量,为四川省乌头种质资源的保护与持续利用提供科学依据.通过查阅文献和比对标本,对青川县、平武县、安县、布拖县、峨眉山市、马边县进行走访和样方调查.结果表明,四川地区野生乌头资源分布较广,北至青川县,南至布拖县,位于27°32'-32°31'N、102°17'-105°11'E,区域内低山至高山均有分布,且集中分布在海拔800-2800m的区域,但由于生态环境破坏严重,总蕴藏量仅为2975kg.建议采取措施保护野生乌头资源的生态环境,实现野生乌头资源的可持续开发利用.  相似文献   

10.
香蕉茎叶资源的开发利用   总被引:7,自引:0,他引:7  
根据我国香蕉资源丰富而茎叶利用不够充分的情况,结合国内外研究现状,阐述了香蕉茎叶资源开发利用的现状和前景.香蕉茎叶除了可以作为饲草资源外,还可用于栽培食用菌、提取盐、医用、造纸等,是一种有待大力开发的农作物资源.  相似文献   

11.
ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m2) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft3/sec (0.085 to 3.34 m3/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.  相似文献   

12.
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   

13.
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   

14.
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   

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.
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   

17.
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   

18.
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   

19.
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   

20.
The maintenance of biodiversity is urged from many quarters and on grounds ranging from aesthetic considerations to its usefulness, particularly for biotechnology. But regardless of the grounds for preserving biodiversity, writers are generally in agreement that it should be preserved. But, in examining the various references biodiversity, such as species diversity, genetic diversity, and habitat diversity, it is apparent that we cannot aim to preserve biodiversityas such, since there are a number of conflicts in any such undertaking. In preserving one aspect of biodiversity, we damage another aspect. Five arguments which attempt to ground our moral concern for biodiversity are reviewed and critiqued, not only for their consistency but also for their power to move us to action. The final section of the paper shows how conflicts in the values of personal and environmental health can impair ethical action and especially policy formation.An earlier version of this paper was read at the conference on Agriculture, Food, and Human Values: Tradition and Change, Orlando, Florida, October 7–9, 1987.  相似文献   

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