共查询到19条相似文献,搜索用时 78 毫秒
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我国林蛙的研究概况和开展环渤海区域林蛙多样性研究的意义 总被引:4,自引:4,他引:4
林蛙是一个复杂多样的类群,我国现有13种,历来是两栖动物分类学和系统学研究的热点之一。本文简要概述了我国林蛙研究的历史及其近10年来的最新研究成果。同时,结合作者近年来的研究,提出环渤海区域是我围林蛙的一个分化中心和热点地区。开展该区域林蛙研究具有重要的科学意义。 相似文献
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介绍了四明山区域野生杜鹃资源的分布情况和主要应用价值,对造成该区域野生杜鹃资源急剧减少的现状进行了原因分析,并提出资源保护和种群恢复对策及合理开发利用建议. 相似文献
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区域可持续发展水平、发展的持续性和系统的协调性是区域可持续发展定量评价研究的三角构架,而在传统上基于各子系统主成分分析结果直接进行形色各异的加权计算对可持续发展评价而言是有待商榷的。提出了非线性主成分分析和施密特正交化(NLPCA-GSO)相耦合的方法评价区域的可持续发展水平来弥补传统方法的不足,并由此建立区域发展持续性模型和可持续发展系统协调度模型,再以环渤海区域为实证分析其2001—2010年的可持续发展状况。结果表明:基于NLPCA-GSO的可持续发展水平模型可以很好地弥补传统主成分分析及对各子系统结果的综合评价的不足;区域发展持续性模型、协调性模型和区域可持续系统变化的滤波分析形象地揭示区域可持续发展的实质和内涵;实证研究表明环渤海区域在研究时段内可持续发展水平有所上升,而环境子系统持续性的下降是引起区域发展持续性和系统协调度的变化的主要原因。研究结果可丰富区域可持续发展评价的方法学,也可为环渤海区域的可持续发展研究奠定基础。 相似文献
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东北林区半人工养殖林蛙对当地自然生态保护影响的调查与分析 总被引:1,自引:0,他引:1
应用资料收集法和实地调查法,调查、评估并分析了东北林蛙养殖区域自然生态变化趋势、东北林蛙养殖业从业人员行为的影响及养殖业发展的可持续性.结果表明开展林蛙半人工养殖的区域几乎全部是自然生态状况良好、具有重要保护价值的区域;林蛙半人工养殖方式极大地提高了区域性森林生态系统中林蛙的数量,进而将导致自然生态系统发生一系列变化,这些变化对自然生态状况的影响有利有弊,并存在不确定性;林蛙养殖从业人员的从业行为或行为倾向,既有有利于当地自然生态保护的一面,也有不利于当地自然生态保护的隐患.在调查与分析的基础上,提出了如下建议:加强林蛙资源本底调查,坚持对林蛙半人工养殖区域自然生态变化的监测和研究,统一林蛙半人工养殖区域各经营活动的经营权,研究制定东北林蛙半人工养殖技术规范,引导从业人员规范操作等. 相似文献
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肖素勤 殷富有 张绍松 余腾琼 陈玲 柯学 付坚 张敦宇 钟巧芳 李定琴 陈越 孙治旭 岳英 郭顺云 王玲仙 黄兴奇 杨雅云 王波 曾民 李娥贤 程在全 《植物遗传资源学报》2017,18(3):494-502
云南野生稻生态类型丰富,且具有抗白叶枯病、抗稻瘟病、耐旱、耐寒等栽培稻不具有或已经消失的遗传基因,是水稻品种改良的优良基因库。然而,随着人类社会经济活动对生态环境影响的加剧,这一宝贵的战略性生物资源正面临着快速消失的危险。为了加强云南野生稻资源的保护,近年来,我们对云南野生稻资源开展了原生境保护(物理隔离方式和主流化方式)及非原生境保护(种质库、种质圃、细胞库和DNA库)等保护技术研究,明确了各种保护方法的优缺点和适用性,保护了云南野生稻的多样性和丰富度,为改良栽培稻储备了丰富的基因源。 相似文献
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河西走廊的麻黄资源及其保护 总被引:9,自引:0,他引:9
河西走廊的麻黄资源及其保护满多清,杨自辉(甘肃省治沙研究所,武威733000)关键词麻黄;植物资源;保护TheresourcesofEphedraTourn.exL.andtheirconservationinHexicorridor¥ManDuo-... 相似文献
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环渤海五省市生态风险评价 总被引:4,自引:1,他引:4
生态风险评价是近20年来兴起的一个研究热点,是地理学、生态学、环境风险评价等领域的综合交叉点。对生态风险进行研究,有助于了解研究区内的生态环境状况,从而降低生态风险,改善人地关系。环渤海地区是人地矛盾非常突出的典型区域。本文参考美国环保署(USEPA)的框架,根据相对风险评价模型的分级排序思想,评估环渤海五省市的单项及综合生态风险值。采用生态资产表征生态终点,进行风险受体的损失度量;通过构建评价指标体系,采用主成分分析和ArcGIS加权叠加的方法,进行受体环境的脆弱性评价;基于土地利用和植被斑块数据,利用景观格局指数法评价生态系统的结构易损性。结果表明:海陆交错带、山地丘陵区和城市是典型的高生态风险区域;低风险区域主要分布在地形、水热、植被状况好、灾害频次低的平原和部分丘陵地区。对于高风险的区域,做好风险防范至关重要。 相似文献
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目的中国林蛙(Rana chensinensis David,1875)是我国林蛙属分布最为广泛的特有种,在上一世纪对其分类问题多有争议,曾被认为广布于中国、蒙古、俄罗斯、日本和朝鲜半岛等。随着对其分类地位的确定,其分布范围也发生了很大变化。为了保护和可持续利用这一重要资源,本文对其分类研究历史和分布进行了总结。方法通过收集、整理和分析研究文献,结合本实验室多年来掌握的野外资料,进行系统的总结。结果中国林蛙自1875年由戴维(中文名为谭卫道)命名以来,曾被划归欧洲林蛙的亚种,并将多种其他林蛙归并入其下。1981年,经过细胞分类学研究,正式恢复为有效种,随后进一步划分出5个亚种。直至本世纪初,经过进一步的分类学研究,厘清了其与东北林蛙和西北林蛙的关系,从而确定其为仅分布于中国的特有种。在此基础上,对其分布也进行了重新确立。结论中国林蛙隶属于蛙科林蛙属中国林蛙种组,目前没有种下分化和亚种形成,分布于我国华北、华中及其周边地区,分布海拔不高于2500m。 相似文献
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青铜峡库区是宁夏唯一有天然森林植被、珍稀候鸟、水生生物与广阔水域组成的自然保护区,素有“黄河森林公园”之称。1967年4月青铜峡水利枢绍建成以后,蓄水量猛增,库容量扩大,水位不断升高,汛期洪水倒灌,水库 相似文献
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We report the isolation and characterization of 19 polymorphic microsatellite DNA markers in the Japanese brown frog (Rana japonica). These markers were tested in 24 individuals each collected from three distinct populations in Ichikai-machi, Tochigi Prefecture. The number of observed alleles per locus ranged from 3 to 24 across all populations, and the values of observed and expected heterozygosities ranged from 0.130 to 1 and from 0.125 to 0.941, respectively. These microsatellite loci will be useful for investigating the intraspecific genetic variation and population structure of this species. 相似文献
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渤海生态通道模型初探 总被引:22,自引:4,他引:22
生态通道模式(Ecopath Model)是一种较为方便地研究生态系统结构,特别是水域生态系统结构的工具,它根据能量平衡原理,用线性齐次方程组描述生态系统中的生物组成和能量在各生物组成之间的流动过程,定量某些生态参数,如生物量、生产量/生物量、消耗量/生物量、营养级和生态营养效率(EE,Ecotrophic Efficiency)等,它能够给出能量在生态通道上的流动量,便于对生态2系统的特征和变化 相似文献
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中国熊类资源数量估计及保护对策 总被引:7,自引:0,他引:7
我国熊类资源丰富,是多熊的国家之一.历史上,我国对熊类资源的猎捕利用,一直维持着较高的水平.然而,近百年来,特别是近50年来,由于人口增多,森林采伐,熊类的栖息条件发生了很大的变化,资源数量显著减少,分布区亦大大缩小,许多原来有熊地区现在已经无熊了,尤其是近10年来活熊取胆汁技术试验成功之后,城乡各地养熊取胆事业一时曾出现高潮,亦给野生种群带来很大的压力,因而,尽快查明熊类资源数量的现状已是急待解决的问题.依据近年的调查及若干重点产区的实地踏查,估计我国棕熊约有5900~7200只,黑熊17500~19500只,马来熊140只左右,本文讨论了数量分布特点、栖息地变化及保护对策 相似文献
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Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0–30, 30–60 and 60–100 cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland. 相似文献
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The present article describes the human activities inthe area and their changes and trends, given that thecontemporary nature conservation key issues areclosely related to past and present socio-economic andcultural conditions, both within Prespa itself andoutside of it. The liberation of Prespa, a remote andrather socially isolated borderline area, from Ottoman occupation took place in 1912–13. Recentevents in its environmental history have been forestclearings and human depopulation in the Civil War(1944–49), irrigation system construction in the1960s, its discovery by ornithologists in the late1960s, the high emigration rates of 1960–1980, itsdesignation as a National Park in 1974, thedestructive development works of 1984–86 afterGreeces entry to the EEC and the conversion to intensivebean cultivation in the mid 1980s.The human population of ca 7000 at the start of thiscentury suffered an almost 80% decrease after theCivil War. A resettlement in the mid 1950s increasedthe population by 40% but in the 1970s emigrationreduced it to its previous size of around 1500, stillits present size. The extensive and diverse farmingsystems of previous centuries changed gradually afterthe construction of an irrigation network in the1960s, which twenty years later and along withinternational changes in production and economypatterns, made possible the present day domination ofa bean monoculture within irrigated croplands. Thiswas accompanied by increased energy inputs,mechanisation and the use of chemicals.Intensification of agriculture brought increasedincomes which attracted also livestock keepers,resulting in a 56% decrease in numbers of livestockin 1964–1993. Cattle are presently kept for meatproduction only. They graze on the mountains, and nolonger in the meadows around the lakeshore. A localshorthorn breed accounting for 93% of all cattle in1963 declined to less than 18% in 1993. Fishing aimedmainly at carp and Prespa bleak, continues today as inthe past to be a source of supplementary income.Eighty-six per cent of the – mainly oak and beech –forests are State owned and the rest belong to localmunicipalities. The forest area has not changedessentially in the last 40 years, but forest roadshave expanded. Forests provide mainly fuelwood forlocal needs and small quantities of industrial timber.No specific management is conducted to safeguard theconservation values of the forest, the majority ofwhich consists of even aged coppiced stands withlimited value for wildlife. Manufacturing never playedan important role for the economy of the area. Tourismhas increased in the last 20 years, concentratedmainly in summer and spring. Accommodation in thevillages is not yet satisfactory though it hasimproved enormously in recent years. The NationalParks infrastructure for visitors remains poor.Tourist pressure generally is not yet that high toimpact drastically the social and environmentalfabric. In places, hunting, angling and poaching cannegatively affect the target species. The constructionof the irrigation network in the eastern part of LakeMikri Prespa was the most important change to thelandscape and the habitats of Prespa the last 30years. It resulted in the embankment of free-flowingstreams, drainage of wet meadows and dramaticreduction of trees and hedges. In the last 15 years,the reedbeds, no longer burnt or mowed and assisted byincreased nutrient loadings from agricultural runoff,have expanded landward to occupy formerly open,periodically flooded, areas. The above changes inhabitats and land use have brought an impoverishmentof biodiversity which can be seen in the exterminationor the decrease in the numbers of certain plant andbird species.The problems preventing a better management of theNational Park and the perpetuation of its values areinappropriate legislation, the poor degree ofcoordination of the public services, the lack of botha specific National Park Service in Greece and amanagement authority for the Park and the hostileattitude of local people due to their limitedinformation and involvement. The scenic beauty, thewetlands and a number of rare habitats, the diversityof habitats, flora and fauna, the endemic life forms,the rare mammals and the colonial waterbirds, thelocal architecture and the cultural expressions suchas the Byzantine monuments, are the values of Prespathat must be preserved as a whole. The initialconservation efforts aimed at preserving biodiversitybut later it became apparent that not only are humansan inseparable part of the whole, but additionally,several of their extensive activities have contributedsubstantially to the rich biodiversity of the area.Through the prerequisites of keeping a balance betweenprimary and tertiary sector activities and ofrevitalizing the social fabric, the following are thekey management and conservation issues of today: anunequivocal agreement on the values to be preservedand their limits; the formation of a managementauthority; a new realistic protection and land usezoning; the diversification and extensification of allfarming activities; the restoration of the wet meadowhabitats; the ensuring of a high water level and agood water quality for both lakes through tri-lateralcooperation between Greece, Albania and FYROM; and theestablishment of a permanent environmental monitoringscheme. 相似文献