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1.
In 1992 parties to the Convention on Biological Diversity (CBD) agreed to develop and implement policies to regulate and facilitate access to genetic resources (AGR). We examine regulations and agreements in Brazil, Colombia, and the Philippines in detail and discuss how these countries are implementing the AGR mandate. In particular, we evaluate progress toward achieving the CBD objectives of conserving biological diversity, using its components in a sustainable manner, and equitably sharing the benefits arising from the use of genetic resources. We highlight the difficulties in developing and implementing these policies, arising from the conflicting goals of regulating and facilitating AGR, as well as the special character of genetic resources, existing ex situ collections, issues of ownership and tenure, and the dearth of legal, institutional, and scientific capacity in many countries. We recommend (1) independent, multidisciplinary evaluation of the success of the access policy in achieving CBD objectives, (2) resolution of the conflict between traditional land tenure and legal property rights of genetic resources so as to match conservation obligations with benefit-sharing rights, (3) recognition that benefits obtained from AGR may be entirely non-monetary, and (4) that countries provide a 'two-track AGR application process separately for commercial and non-commercial users.  相似文献   

2.
Bolivia is a megadiverse country. A large part of its biodiversity is due to the fact that in its territory different biogeographical regions meet. As a preliminary means to understand how this biodiversity is being protected, three previous studies undertook an evaluation of how well represented the ecological regions were in the National System of Protected Areas (NSPA). However, the most recent biogeographical findings in Bolivia call for a new analysis of this sort. We try to achieve this, emphasizing the situation in the Andean dry regions, which have been given scarce priority, despite their high biological value. In general, xeric ecoregions are under-represented while humid ones are over-represented. The Prepuna and the central altiplano (which includes the Dry Puna sub-ecoregion) are not represented within the NSPA, nor is the Beni Cerrado sub-ecoregion. The Inter-Andean Dry Valleys cover only ca. 0.5% of the protected area, in spite of their diverse flora and status as one of Bolivia’s most important centers or endemism. Although the diverse Chiquitos Dry Forest is well represented, it is protected mostly as an ‘Integrated Management Natural Area’, and thus lacks full protection. The Semi-Humid Puna and the Flooded Savannas of the Moxos Plains, important subdivisions of two main ecoregions, are markedly under-represented in the NSPA, despite the importance of Moxos plains as a center of endemism for birds. Other ecoregions have a representation in the NSPA which can be considered adequate or even excessive. The over-representation of the humid Yungas mountain forests seems to be justified as this is probably Bolivia’s most important center of diversity and endemism. There is a need for a more proper distribution of some protected areas which consider true limits, size, diversity, endemism and other attributes of the different ecoregions in a more rigorous manner.  相似文献   

3.
以实现景观和环保2项功能为主要目标,对老山国家森林公园的4类群落林相进行改造,分别将马尾松(Pinus massoniana)纯林群落(A1)、朴树(Celtis sinensis)纯林群落(B1)、水杉-侧柏(Metasequoia glyptostroboides-Platycladus orientalis)针叶混交林群落(C1)和以落叶树为主的麻栎-朴树(Quercus acutissima-Celtis sinensis)阔叶混交林群落(D1)改造成马尾松-锦绣杜鹃(P.massoniana-Rhododendron pulchrum)群落(A2)、朴树-乌桕-桂花-枸骨-红叶石楠-绵枣儿(C.sinensis-Sapium sebiferum-Osmanthus fragrans-Ilex cornuta-Photinia×fraseri‘Red Robin’-Scilla scilloides)混交林群落(B2)、水杉-侧柏-枫香树-构树-棕榈-阔叶山麦冬(M.glyptostroboides-P.orientalis-Liquidambar formosana-Broussonetia papyrifera-Trachycarpus fortunei-Liriope platyphylla)针阔叶混交林群落(C2)和以常绿树为主的麻栎-朴树-香樟-女贞-桂花-凤尾丝兰-海桐-阔叶山麦冬-络石(Q.acutissima-C.sinensis-Cinnamomum camphora-Ligustrum lucidum-Osmanthus fragran-Yucca gloriosa-Pittosporum tobira-Liriope platyphylla-Trachelospermum jasminoides)阔叶混交林群落(D2)。应用层次分析法(AHP),从群落结构和群落效益2方面,选取郁闭度、物种丰富度、构景层次、树冠水平投影重叠面积、常绿落叶比、吸收有害气体能力、滞尘与杀菌能力、季相变化、景观优美度和游憩资源10项评价指标,根据各指标的权重和赋值建立了城市森林公园景观环保型林相改造模式的评价体系。评价结果显示:改造后的群落林相各项指标得分值及综合评分值均高于改造前的群落,特别是群落D2的构景层次、季相变化与景观优美度最佳,对环境的净化功能最强,实现了景观与环境保护的有机结合。结果表明:城市森林公园景观环保型群落模式改造既要考虑植物自身的生理生态特征,也要注重植物的个体美与群体美等因素。  相似文献   

4.
Wildlife-vehicle collisions have been identified as an important ecological problem in most countries around the world, during the last decades. In the present work we examined the impacts on wildlife arising from two road categories crossing and adjoining the Dadia-Lefkimi-Soufli National Park (DLS NP), in north-eastern Greece. The study area is consisted of one of the most diverse fauna in Europe, with 202 bird species including 36 out of 38 European diurnal raptors, 60–65 mammal species, 29 reptiles and 13 amphibians. Vehicle collisions was the highest mortality factor in the study (83.9%) among five recorded categories, poison, electrocution, drowning, vehicle collisions and unidentified causes. 204 vehicle casualties were recorded out of 243 in total. Mammals (90.7%) were the vertebrates that mainly suffered from road mortality, including 11 species. The stone marten Martes foina contributed with the highest numbers, followed by the red fox Vulpes vulpes, the hedgehog Erinaceus roumanicus and the wild cat Felis silvestris. Although the contribution of birds on the road casualties was low, nine species were identified, including five diurnal and four nocturnal species, with raptors predominating. Most road casualties were observed in the national road network (71.6%), mainly during holidays (58.3%). Traffic volume, road category, season and blind bend were all dominant factors with different effects determining high wildlife-vehicle collision values. Mitigation measures that can reduce the harmful effects of roads on wildlife in the DLS NP are also discussed.  相似文献   

5.
白爱芹  傅伯杰  曲来叶  王淼  孙家宝 《生态学报》2013,33(17):5201-5209
通过对大兴安岭重度火烧迹地不同坡度和坡向的土壤微生物群落进行调查研究,旨在揭示重度火烧迹地过火6a后森林恢复过程土壤微生物群落的变化规律与影响因素.研究结果表明:平地土壤微生物生物量碳含量(MBC)和土壤微生物生物量碳氮比(MBC/MBN)均高于坡地,其中MBC/MBN达到差异极显著水平.平地土壤微生物的代谢活性AWCD值、对31种4类碳源(糖类、脂类、氨基酸、代谢物)的利用能力和Shannon-Winner多样性指数(H')均极显著低于坡地.西坡土壤微生物AWCD值和H'高于南坡,但AWCD和H'与土壤养分、pH值、EC无显著相关关系,说明坡向可能与土壤微生物代谢活性和多样性的关系并不密切,反映了两坡向土壤微生物群落结构的相似性.坡度由于影响了土壤养分和水分条件,进而影响了土壤微生物的生物量、群落结构、物种多样性和碳源利用能力.火烧迹地恢复初期平地土壤微生物量碳高于坡地,西坡高于南坡;恢复6a后,土壤微生物量碳的差异己不显著,但土壤微生物群落结构、物种多样性以及代谢特性仍具有显著差异,这可能与地形坡度仍然显著影响土壤水分含量的因素有关.  相似文献   

6.
《关于建立以国家公园为主体的自然保护地体系的指导意见》提出国家公园实行管控分区的要求,以便实现国家公园最严格保护目标。然而,国家公园管控分区评价的指标尚不明确,以浙江钱江源国家公园体制试点区(以下简称"钱江源国家公园")为研究对象,采用层次分析法从基础环境(包括高程、植被指数、交通道路影响和基本农田)、重点野生动植物分布(野生动植物、黑麂生境适宜性和白颈长尾雉生境适宜性)、自然资源保护基础(古田山国家级自然保护区、钱江源国家森林公园、钱江源风景名胜区和生态公益林)和生态现状(生态功能适宜性评价、自然资源承载力、三区三线和土地利用现状)等指标构建多源数据空间分析指标体系,利用空间叠加分析技术获取钱江源国家公园的管控分区结果,并与管控分区最终结果进行对比分析。结果表明:(1)基于多源数据的方法能有效地识别钱江源国家公园内生态保护价值较高区域;(2)多源数据空间分析结果与最终管控分区结果对比显示,其总体精度为78.07%(197.70 km2),在核心保护区精度为83.55%(127.99 km2),一般控制区精度为69.67%(69.71 km2);(3)影响精度主要原因是新调入区域基础数据不足,以及通过定性分析解决管控分区破碎化等。研究认为基于多源空间数据分析技术能够客观、高效地划分国家公园管控分区,具有一定普适性,但仍需通过增加数据数量或优化算法提高精度。  相似文献   

7.
郭甲嘉  沈大军 《生态学报》2022,42(15):6430-6438
随着经济社会的发展,中国自然保护地体系经历了由以自然保护区为主体向以国家公园为主体的重要变迁。应用多源流理论分析了中国自然保护地体系变迁。从内在逻辑、民主化程度和变量控制三个方面分析了多源流理论在中国保护地变迁研究中的适用性;从问题源流、政治源流和政策源流三个方面分析了中国自然保护地体系变迁的主要影响因素,梳理了变迁的逻辑路线,总结了变迁的内容,变迁内容包括管理客体、管理主体和管理手段三个方面。结果表明:中国自然保护地体系变迁是问题源流、政治源流和政策源流共同作用的必然结果,表现在问题源流中的指标数据和问题反馈促进了政策源流中政策建议和方案的提出,而焦点事件与政治源流中执政理念的冲突对变迁起到了重要的催化作用;政策源流存在渐进式完善过程,尤其是国家公园体制试点对政策源流的发展起到关键作用。此次变迁的逻辑路径主要包含三股源流的相互作用,通过引入国家公园重塑中国自然保护地体系,促进其系统性、整体性和协同性发展。  相似文献   

8.
广东鼎湖山自然保护区森林景观的动态模拟研究   总被引:2,自引:1,他引:1  
彭月  魏虹  朱韦  王永健   《广西植物》2007,27(2):186-190
在遥感和GIS系统支持下,以1991年和1999年两个时期的Landsat-TM合成影像为基础,利用马尔科夫模型,模拟鼎湖山自然保护区森林景观的动态演变。结果表明:常绿阔叶林面积增加,除水域外,其它面积相应减少,到达稳定期,区域内大多为常绿阔叶林,少量的混交林,其它类型几乎消失。这个趋势是和该地区森林的演替规律相符的,但是这种结果对维持保护区内的景观多样性是不利的。  相似文献   

9.
唐承财  刘嘉仪  秦珊  江玲  吕君 《生态学报》2024,44(13):5786-5800
探究生态产品价值实现的机制及模式是国家公园加快生态文明建设、推动"绿水青山"向"金山银山"转化的关键。构建了国家公园社会-经济-自然复合生态系统,分析国家公园生态产品特征并划分类别,以神农架国家公园试点为例,探究了国家公园生态产品价值的实现路径与机制,建立了国家公园生态产品价值实现模式。结果表明:(1)国家公园复合生态系统由社会、经济和自然生态系统构成,形成一个相互影响、相互关联的整体。(2)国家公园生态产品具有生物生产性、资源稀缺性、人类收益性、地域整体性、政策依赖性、利益平衡性等特征,识别与分类生态产品有助于复合生态系统的平稳运行与健康发展,进而实现生态产品价值。(3)国家公园生态产品总体分为公共性、准公共性和经营性三类,并由政府主导、社区主导、市场主导与多主体复合型路径组成的价值实现路径体系完成价值实现。(4)国家公园生态产品价值实现机制由生态保护机制、经济发展机制、社区进步机制和协调保障机制四部分构成,服务于生态保护、产业发展和社区振兴三个目标。(5)国家公园生态产品价值实现过程中存在一定问题,以生态保护为首要任务、旅游发展为实现路径、社区振兴为核心目标,构建神农架国家公园"生态保护-旅游发展-社区振兴"共生模式,并进一步提出生态产品价值实现的生态旅游模式,以协调处理神农架国家公园复合生态系统结构内的矛盾,实现国家公园生态产品价值的最大化。综上所述,丰富了生态产品价值实现理论,并为国家公园生态产品价值实现模式提供了重要的科学依据与决策参考。国家公园"生态保护-旅游发展-社区振兴"的共生模式以及国家公园生态产品实现的生态旅游模式,将为国家公园生态产品价值的实现提供更加全面与有效的路径与模式。  相似文献   

10.
生物多样性监测是国家公园保护的核心基础。大熊猫国家公园是我国首批5个国家公园之一, 系统的保护规划与有效的管理行动均有赖于对区内生物多样性本底、现状与动态的深入了解。为了解大熊猫国家公园范围内兽类与鸟类多样性本底与现状, 本研究系统检索了该区域内2005-2020年基于红外相机调查技术的野生动物研究论文、项目报告以及新闻报道, 并对区内原有保护地的红外相机监测历史与结果进行了问卷调查。结果表明, 2005-2020年期间, 在大熊猫国家公园范围内51个保护地的红外相机调查与监测中, 共记录到分属6目22科55属的71种野生兽类与分属13目45科132属的232种野生鸟类。在国家公园所覆盖的秦岭、岷山、邛崃山、相岭4大山系中, 邛崃和岷山记录到的大中型地栖鸟兽物种多样性最高(均为兽类40种, 鸟类12种), 相岭最低(兽类25种, 鸟类7种)。单个保护地中记录到的大中型地栖鸟兽物种数量与保护地面积、红外相机有效工作日及相机位点的海拔跨度均呈正相关, 国家级保护地中记录到的物种数(28 ± 8.3, mean ± SD)显著高于省级保护地(19 ± 8.9)。在大熊猫国家公园内共记录到猫科与犬科的4种大型食肉动物, 即豹(Panthera pardus)、雪豹(P. uncia)、狼(Canis lupus)和豺(Cuon alpinus), 主要来自于秦岭山系和邛崃山系, 而国家公园内的岷山山系则没有记录到大型食肉动物, 相岭山系中仅有1次狼的记录。本研究结果显示, 大熊猫国家公园内前期已经建立起的自然保护地网络与红外相机监测体系已积累大量区内野生兽类与鸟类的基础数据, 为国家公园的试点与建设提供了生物多样性编目与监测方面的可靠本底。在这些前期工作的基础上, 大熊猫国家公园应进一步规划、建设标准化的野生动物监测体系, 为今后国家公园的管理决策、成效评估提供坚实的科学支撑。  相似文献   

11.
伏牛山自然保护区森林生态系统草本植物功能群的分类   总被引:10,自引:1,他引:9  
伏牛山国家级自然保护区是中国东部森林样带中的亚热带和暖温带的结合点,随着环境梯度(海拔)的变化,林下植物优势种变化明显.草本植物对环境的反应较为敏感,能较好的反映出植被与环境的动态关系.采用群落学调查方法,对伏牛山南北坡的植被进行调查.以X2检验为基础,结合联结系数AC和共同出现百分率PC来测定草本层优势种间的联结性,根据优势种间的联系性及其在海拔梯度上的变化异同,以优势种为主体划分伏牛山自然保护区林下草本植物功能群.研究结果表明,以优势种为主体对森林生态系统草本植物进行功能群划分可行性高,有较强的代表性.对草本优势种共划分了7组植物功能群:Ⅰ"伴人型",Ⅱ"高山型",Ⅲ"阴湿型",Ⅳ"耐旱型",Ⅴ"林隙型",Ⅵ"基础型",Ⅶ"原始型".每一组都有其特定的分布区域和形态特征,较好了反应出环境与植被的动态关系,为今后森林生态系统研究和植物功能群划分寻找新的思路.  相似文献   

12.
Knowledge of the levels of genetic diversity maintained in natural populations can play a central role in conservation programmes, particularly in threatened habitats or species. Fluctuations in population size can lead to loss of variation and, consequently, increase the risk of extinction. We have examined whether such a genetic bottleneck has occurred in populations of two species in the seagrass genus Zostera, which are believed to have been affected by an outbreak of wasting disease at the start of the last century. A test for heterozygote excess at five nuclear microsatellite loci did not suggest the occurrence of a genetic bottleneck, but analysis of seven chloroplast microsatellite loci and sequence data from two regions did suggest a bottleneck in the chloroplast genome. Extremely low levels of between-population diversity suggest that all subpopulations can be treated as a single management unit for each species. Comparable levels of nuclear genetic diversity were found in the three populations of the primarily sexual Zostera marina var. angustifolia studied but a wider range of within-population diversity was found in Zostera noltii, which displays both sexual and vegetative reproductive strategies. This may be due to an increase in sexual recruitment due to localised fresh water inflow into the study site near to the most diverse population. Such populations should be prioritised as source material for any replanting or remediation due to natural or anthropogenic loss of Zostera beds in the area.  相似文献   

13.
Certain species of terrestrial chironomids (Diptera) are specialised on open patches in initial stages of primary or secondary succession (early fallow, lichens and mosses on rocks, etc.). These "source" habitats provide good quality food for their larvae and most offspring are produced here, but they are sensitive to summer desiccation. This often results in extinction of the summer larval population, followed in winter by re-colonisation from less suitable, but more stable "sink" habitats in the surrounding landscape. Soil dwelling and long-lived larvae are poor migrants; short-lived, winged adult females select patches for their development. Proper choice of oviposition sites and consequent distribution of eggs among individual habitats is thus critical for the success of these species. A mathematical model was developed in order to find out whether this re-colonisation strategy could ensure population persistence at the landscape level. The model was verified using long-term data on Smittia atterima abundance in old fields. The results indicate that even a small proportion of eggs laid in a sink habitat can ensure a successful re-colonisation of the source habitat. Thus, re-colonisation of source habitats from sink habitats is concluded to be one of the reasons for persistence of the latter. The model indicates that this re-colonisation may ensure population persistence even in conditions when exclusive use of only one habitat leads to population extinction either due to environmental stress or to a negative growth rate.  相似文献   

14.
Established under the European Union (EU), the thirty-year trans-national network, Natura 2000, is considered one of the largest biodiversity conservation frameworks worldwide. The global financial crisis has afflicted European economies since 2008 and has not only caused radical changes to the economic development but has also resulted in major implications on nature conservation activities in one of the weakest EU member states, however a biodiversity hotspot, Greece. The present research constitutes a broad-based assessment of the effects of the current economic crisis on the application of the EU Birds and Habitats Directives by the Greek state for the first time. By applying an expert elicitation method, Policy Delphi, we attempt to address the impact of the crisis on the administrative levels, competent authorities and procedural frames of the national protected area system, as perceived by 38 Greek key stakeholders and experts on the topic. An evaluation of the practices and obligations of 4 Management Bodies of the Greek protected area system was conducted to get an insight of the financial consequences on their operation. The structured and participatory approach followed in this study, allowed a systematic collection of experts’ transdisciplinary judgments on the state of the Greek Natura 2000 network in terms of implementation, management, administration, monitoring and legislation. With a strong tradition in managing its high nature value in a centralized way, in the face of the economic crisis, implementation challenges of the Greek state concerning Natura 2000 have been enlarged. According to a substantial part of the Greek conservation community that participated in the survey, many enforcement obstacles are considered, either direct or indirect consequences of the economic crisis, while some are inherent to the lack of a national comprehensive conservation strategy and not necessarily attributed to the austerity. However, the lack of national structural strength, as illustrated by the respondents, rather than the funding size proved to be an important cause of vulnerability for the Greek network. Based on the findings of this study we propose recommendations for improvements that align economic with conservation interests and measures that can substantially counteract the negative impacts of the economic austerity on the enforcement of nature conservation.  相似文献   

15.
Snorkelling surveys using a point abundance method revealed high levels of microhabitat differentiation among 14 fish species from a high-visibility site in the middle reaches of the Gambia River. Habitat segregation was most strongly related to the position in the water column, flow velocity, substratum composition and presence of submerged wood.  相似文献   

16.
“三生”空间的优化布局,有赖于对"三生"空间变化所产生的地域功能效应的认识,社会生态服务价值分析为这一效应评价提供了新的途径。以邛海国家湿地公园为例,采用参与式制图与半结构化访谈方法调查当地居民感知的社会生态服务价值变化类型,最终获取有效问卷与填图393份,提取空间数据点1830个。通过质性空间分析等方法研究湿地公园建设以来"三生"空间变化对社会生态服务价值的影响,探讨地域功能的尺度特征及其变化趋势与效应。研究表明:(1)湿地公园建设以来"三生"空间格局变化剧烈,主要表现为生产空间转换为生态空间与生活空间,前者占据主导地位,呈带状分布在邛海湿地周围,后者则呈斑块状分布在各村落周边;(2)利用Nvivo11软件进行质性分析,将归纳出的6种社会生态服务价值与区域性、地方性地域功能相联系,发现在城郊保护地"三生"空间变化中,区域性地域功能增益明显,而地方性地域功能表现出增益与贬损交织的复杂变化特征,不同尺度地域功能间存在协同与冲突的多重关系;(3)研究指出区域"三生"空间配置过程中,既要关注地域功能在地域间的水平综合均衡,也要兼顾不同尺度地域功能间的垂直综合均衡,才能实现区域效益的最优化。城郊保护地在受到外部结构化力量和社区内部适应能力的双重作用下发生地域功能转化,社区参与的质性空间评价则为认识地域功能转化过程、效应及调控策略提供了途径。  相似文献   

17.
全球气候变暖对陆地生态系统尤其是森林生态系统有着重要的影响,气温升高、辐射强迫的增强将显著改变森林生态系统的结构和功能.南方人工林作为我国森林的重要组成部分,对气候变化的响应日益强烈.为了探究未来气候情景下我国南方人工林对气候变化的响应,降低未来气候变化对人工林可能带来的损失,本研究采用3种最新的气候情景—典型浓度排放路径情景(RCP2.6情景、RCP4.5情景、RCP8.5情景)预估数据,应用生态系统过程模型PnET-Ⅱ和空间直观景观模型LANDIS-Ⅱ模拟2014—2094年间湖南省会同森林生态实验站磨哨实验林场森林的地表净初级生产力(ANPP)、物种建立可能性(SEP)和地上生物量的变化.结果表明: 不同森林类型的SEP和ANPP对气候变化的响应有明显的差异,各森林类型对气候变化的响应程度表现为: 对于SEP,在RCP2.6和RCP4.5情景下,人工针叶林>天然阔叶林>人工阔叶林;在RCP8.5情景下,天然阔叶林>人工阔叶林>人工针叶林.对于ANPP,在RCP2.6情景下,人工阔叶林>天然阔叶林>人工针叶林;在RCP4.5和RCP8.5情景下,天然阔叶林>人工阔叶林>人工针叶林.人工针叶林的地上生物量在2050年左右开始下降,天然阔叶林和人工阔叶林整体呈现上升趋势.2014—2094年,研究区地上总生物量在不同气候情景下增加幅度不同,RCP2.6情景下增加了68.2%,RCP4.5情景下增加了79.3%,RCP8.5情景下增加了72.6%.3种情景下的总地上生物量大小排序为: RCP4.5> RCP8.5> RCP2.6.我们认为,适当的增温将有助于未来研究区森林总地上生物量的积累,但过度的增温也可能会阻碍森林的生产和生态功能的持续发展.  相似文献   

18.
土壤层水源涵养功能是森林水源涵养功能的主体。目前关于森林土壤水源涵养功能的研究主要集中在林地或坡面尺度上。由于流域尺度,尤其是环境空间异质性强的西南亚高山区流域,如何将林地尺度实测结果上推至流域或更大空间尺度仍是生态水文领域面临的巨大挑战之一。以川西岷江上游杂谷脑流域为研究对象,融合多种森林类型样地实测与流域尺度多源遥感数据,构建了基于植被和环境因子的林地-流域森林土壤水源涵养功能尺度转换模型,实现了流域尺度土壤水源涵养功能快速评价及其空间分布预测。样地尺度研究结果表明各类型森林的土壤水文特性各异,总体表现为天然林优于人工林,混交林优于单纯林。林地土壤持水能力受到区域气候、植被、土壤及地形等因子的共同影响,其中风速、NDVI及林龄与土壤最大持水量、毛管持水量及非毛管持水量均呈极显著正相关(P<0.01)。基于关键植被和环境因子构建的林地-流域土壤水源涵养功能尺度上推模型精度较高,土壤最大持水量、土壤毛管持水量和土壤非毛管持水量模型拟合优度R2分别为0.700、0.720和0.908;土壤最大持水量、土壤毛管持水量和土壤非毛管持水量的模型预测值与野外实测值的相关系数介于0.69-0.79之间,平均误差均低于20%,表明模型预测结果可靠。利用构建的土壤水源涵养功能尺度上推模型,估算得出流域尺度森林土壤持水量的空间分布,其结果表明杂谷脑流域森林土壤持水量空间分异明显,海拔较高区域森林土壤持水量最高,其次为距道路和河流有一定距离的缓坡地带,下游干旱河谷地区土壤持水量最低。本研究为亚高山森林生态功能的恢复和提升提供了科学依据和评价工具。  相似文献   

19.
The health-promoting properties of dietary long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFAs) for humans are well-known. Products of animal-origin enriched with n-3 LCPUFAs can be a good example of functional food, that is food that besides traditionally understood nutritional value may have a beneficial influence on the metabolism and health of consumers, thus reducing the risk of various lifestyle diseases such as atherosclerosis and coronary artery disease. The traditional method of enriching meat, milk or eggs with n-3 LCPUFA is the manipulation of the composition of animal diets. Huge progress in the development of genetic engineering techniques, for example transgenesis, has enabled the generation of many kinds of genetically modified animals. In recent years, one of the aims of animal transgenesis has been the modification of the lipid composition of meat and milk in order to improve the dietetic value of animal-origin products. This article reviews and discusses the data in the literature concerning studies where techniques of genetic engineering were used to create animal-origin products modified to contain health-promoting lipids. These studies are still at the laboratory stage, but their results have demonstrated that the transgenesis of pigs, cows, goats and fishes can be used in the future as efficient methods of production of healthy animal-origin food of high dietetic value. However, due to high costs and a low level of public acceptance, the introduction of this technology to commercial animal production and markets seems to be a distant prospect.  相似文献   

20.
叶艳妹  林耀奔  刘书畅  罗明 《生态学报》2019,39(23):8846-8856
“山水林田湖草生命共同体”是人与自然和谐共处的指导原则,也是人类实现可持续发展的有效实践路径。根据Ostrom提出的社会-生态系统(SES)框架,以浙江省钱塘江源头区域为研究区,构建集流域、陆地和人类活动为一体的社会-生态系统(SES)概念框架,为生态修复工程提供一个问题导向的分析策略。研究发现基于Ostrom构建的钱塘江源头区域山水林田湖草生态修复工程的SES框架,可以用来诊断关键问题、分析影响因素、设定行动情景和评估结果,从而形成完整的实施和解决问题策略。由诊断关键问题得出,该区域面临地质灾害多发、水土流失、环境污染、生物结构单一等多重问题,而人类活动如城市扩张、过度开发自然资源、污染物排放等则是造成社会-生态系统失衡的主要因素。通过行动情景设置将SES框架中涉及的影响因素、解决途径、评价标准、期望的成效以及反馈机制等进行梳理,对研究区的社会-生态系统进行全面分析。根据设立的评价体系对生态修复工程进行生态环境和社会经济效果的动态评估,并不断地根据评价结果进行修正以获得最佳的预期成效。该框架为解决钱塘江源头区域山水林田湖草生态修复工程所面临的问题提供了一个系统的解决方案,并可根据研究区的特点进行相应调整,是一个具有强适用性的社会-生态系统分析框架。  相似文献   

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