严防巴西龟对重庆水生生态系统的影响

文章阐述了外来入侵物种巴西龟对重庆本土龟类以及生态环境的影响,提出生物多样性保护对策,旨在为保护本土龟类及水生生态系统提供参考。     

外来入侵物种

外来入侵物种:科学家把一些原本不产在当地的物种,称之为外来物种,一旦它们适应当地生态环境而可以自行繁殖,乃至与当地物种产生激烈的竞争,并剥夺当地物种生存的时候,也就构成了一种毁灭性侵略,故名”外来入侵物种”。 外来入侵物种对本地生物多样性和生态环境造成     

内蒙古外来入侵物种及其对草原的影响

生物入侵严重威胁着内蒙古草原的生物多样性和生态安全。目前,内蒙古地区乃至于全国对外来物种只重引进、疏于管理,导致外来物种逃逸到自然环境中,造成潜在的环境灾害。本研究据文献查阅以及中国外来入侵物种数据库信息,整理分析内蒙古境内分布的外来入侵物种的种类、来源地、侵入途径及对草原的危害状况,并对内蒙古草原应对外来物种入侵提出了相应的防控措施。根据统计,外来入侵植物中的牛膝菊(Galinsoga parviflora)和光梗蒺藜草(Cenchrus calyculatus)已表现出蔓延趋势,其他物种有待进一步的调查。     

加拿大一枝黄花研究进展

外来植物的引入或入侵,对我国农林牧业已经产生了惊人的直接经济损失,它们引起生态系统紊乱、生物多样性的丧失而造成的间接经济损失更是无法估计。外来植物入侵已成为生物多样性保护和生态系统恢复研究的热点问题,对外来种的入侵理论,即入侵生态学的研究也正在兴起。通过从外来入侵植物加拿大一枝黄花的生物学特性、对环境条件的适应性、对植物多样性的危害、药用价值及防治方法等方面进行了综述。     

中国外来物种入侵达500多种 1年损失570亿元

外来生物的入侵,在严重干扰生态系统的同时,还给我国带来了年均超过570亿元的经济损失。2014年7月29日农业部发布消息称,入侵我国的物种达到529种。其中大面积发生、危害严重的达100多种,对我国生物多样性以及农牧业生产等构成了巨大威胁。农业部农业生态与资源保护总站站长王衍亮介绍,从20世纪80年代以来,外来物种在我国呈现出更快的增长趋势,近10年新增入侵物种近50种,20余种危险性入侵物种接连在我国大面积爆发成灾。外来生物入侵范围也相当广泛,涉及农田、湿地、森林、河流、岛屿、城镇居民     

辽宁省外来入侵有害生物特征初步分析

通过2006-2008年野外实地调查和文献资料分析,对辽宁省外来有害生物进行总结。结果表明,目前对辽宁省造成危害的外来物种共计116种,分别为外来植物89种、外来害虫17种和外来病原微生物10种,其中危害性较强的主要有14种。这些外来物种的传播和扩散速度较快,传播途径多以无意引入为主,对辽宁省的经济和生态环境危害严重。外来物种入侵地多为生态系统结构单一的农田草场或人工林系统;入侵地多为辽宁省气候温暖湿润的南部,且生物多样性比较丰富的地区。     

外来入侵种的危害与防治对策

外来入侵种对当地的自然生态系统结构和功能以及生物多样性都有着深远的影响,而且可能对地方的生态环境和经济造成严重危害。四川已经成为遭受外来入侵种威胁的省份之一,全省现有20多个外来入侵种。为了防止外来入侵种的泛滥,应当建立外来物种的引入评价机制,慎重进行有意引种;加强口岸管理,防止外来入侵种通过贸易途径无意引入,同时采取措施控制已经产生危害的外来入侵种。     

外来入侵种的危害与防治对策

外来入侵种对当地的自然生态系统结构和功能以及生物多样性都有着深远的影响,而且可能对地方的生态环境和经济造成严重危害.四川已经成为遭受外来入侵种威胁的省份之一,全省现有20多个外来入侵种.为了防止外来入侵种的泛滥,应当建立外来物种的引入评价机制,慎重进行有意引种;加强口岸管理,防止外来入侵种通过贸易途径无意引入,同时采取措施控制已经产生危害的外来入侵种.     

论外来入侵物种与特种动物引种

改革开放以来,特种动物的引种工作促进了我国养殖业的快速发展。但由此外来物种引进而引发的外来物种入侵,不仅是导致生物多样性丧失的主要原因之一,而且还威胁着全球的生态环境和经济发展,因而成为举世瞩目的焦点问题。据报道,我国外来物种入侵已造成我国引进地物种的减少甚至灭绝,导致生态功能的     

外采入侵种的危害与防治对策

外来入侵种对当地的自然生态系统结构和功能以及生物多样性都有着深远的影响，而且可能对地方的生态环境和经济造成严重危害。四川已经成为遭受外来入侵种威胁的省份之一，全省现有20多个外来入侵种。为了防止外来入侵种的泛滥，应当建立外来物种的引入评价机制，慎重进行有意引种：加强口岸管理，防止外来入侵种通过贸易途径无意引入，同时采取措施控制已经产生危害的外来入侵种。     

Fuel Reduction,Seeding, and Vegetation in a Juniper Woodland

Western juniper has increased in density and distribution in the interior Pacific Northwest since the late 1800s. Management goals for many juniper woodlands are now focused on reducing tree densities and promoting biodiversity, prompting the use of fuel reduction treatments. Fuel reduction often involves mechanical cutting and disturbances such as slash pile burning and skid trail formation. While these activities may reduce tree densities, the extent to which they will restore native biodiversity and community composition, particularly in woodlands invaded by exotic annual grasses, is unclear. We evaluated the effects of juniper cutting in two experiments of disturbance type (slash piles and skid trails) followed by three native seeding treatments (cultivar, locally sourced, and no seed) on vegetation in central Oregon. Prior to cutting, native perennial grass cover and richness were positively associated and exotic grass cover was negatively associated with juniper basal area. After cutting and 2 yr after seeding, species composition was altered for both disturbance types. Some seeded areas had higher total species richness, higher native species richness, higher cover of seeded species, and higher overall cover compared to areas that were not seeded. But seeding effectiveness in mitigating exotic species spread varied based on exotic species functional group, pretreatment propagule pressure, and experiment disturbance type. Neither seed mix lowered exotic grass cover. There was limited evidence that the cultivar mix outperformed the locally sourced native seed mix. In the short term, fuel reduction activities may have facilitated further conversion of this woodland to an exotic grassland, but longer-term evaluation is needed. In juniper woodlands that have been invaded by exotic species, fuel reduction activities may facilitate further invasion, and exotic species control may be needed to limit invasion and promote native vegetation.     

豚草属植物研究进展

外来物种的入侵已经对我国的农林牧业造成了巨大的经济损失,也严重破坏了生态系统的平衡和物种多样性的保持。作为我国五大入侵植物之一的豚草,更是对人体有严重的致敏作用,在每年的8-9月份能够造成大面积的花粉过敏疾病。它不仅危害人体的健康,对环境和农业生产的危害也非常严重。因此豚草属植物作为外来入侵植物的代表应该更多的被认识其各种特点和习性,以便于进一步防范和治理。本研究对豚草属植物的生物学特性、生态学特性、危害、防治和利用等方面进行了综述。     

Distribution pattern of endangered bird species in China

In this study, we determined six “hotspots” for avian biodiversity conservation in China. We analyzed the distribution patterns of 183 threatened bird species in China in conjunction with geographical data to produce a distribution map that shows the concentrations of threatened species. The six biodiversity hotspots are: the western Tianshan Mountains; the Qilian and Hengduan mountains; southern Anhui, southern Jiangsu, and the Zhejiang Hills; the Songliao Plain and the northern region of the North China Plain; the island of Taiwan; and the island of Hainan. Based on our analysis of a species–habitat matrix, species were determined to be distributed mainly in broadleaved forest, grassland and meadows, urban and agricultural areas, wetlands, and bush. Most species were commonly found to have a range of three to five different habitat types. Apart from the six biodiversity hotspots, six ecological clusters were determined. Protection strategies indicating different levels of habitat priority among the biodiversity hotspots were also recommended.     

生物入侵对生物多样性以及草地农业生态系统的影响

从生物入侵的原理、生物多样性的概念以及草地农业生态系统的健康评价方面对三者的内在生态关系进行了分析和探讨,以期达到合理引入外来物种、保持生物多样性和稳定草地农业生态系统的三重效应.并在此基础之上提出如何保持生态平衡,使草地农业生态系统能够达到经济、社会和生态三盈,做到可持续的发展.     

外来牧草入侵风险评估体系研究

风险评估是预防外来物种入侵的有效手段,为科学评价外来牧草的入侵风险,防止盲目引种带来生态安全威胁,本研究将频度分析法与层次分析法结合,建立外来牧草入侵风险评估指标体系;该体系由5个一级指标和18个二级指标组成,包括外来牧草的入侵性、适应性、扩散性、生物学特性、危害性、防除难度等方面;本研究中,利用4种禾本科外来入侵牧草和3种禾本科外来牧草对构建的评估体系进行验证,并利用该体系对外来牧草柳枝稷（Panicum virgatum L.）进行了入侵风险评估实例研究,得出其入侵风险为中等,主要体现在适应性强和扩散性强方面。本研究建立的评估体系,可初步明确柳枝稷入侵风险的主要来源,为外来牧草的引种管理提供参考。     

外来植物黄顶菊的入侵机制及生态调控技术研究进展

黄顶菊是近年来入侵我国的一种外来植物,其强大的繁殖能力和入侵性已经对生态环境造成了严重的危害,同时也威胁到农业生态安全。基于此,笔者围绕黄顶菊入侵的生态学机制和生态调控方法等进行了综述。首先,黄顶菊的化感作用和其对不利环境条件的快速适应能力对其入侵扩张具有重要作用;其次,黄顶菊和土壤生态系统之间可能形成“正反馈”作用机制,而这种机制又进一步促进了其成功入侵,其对土壤生态系统包括对养分循环、酶活性和微生物的组成和功能等均产生了深远影响;最后,遵循种群演替的基本规律,可通过建立能与黄顶菊抗衡的本地植被实现生态重建从而达到遏制其扩张,其中选择竞争力强且适合当地气候条件的植物材料至关重要。在此基础上,笔者围绕如何有效控制黄顶菊的危害尚需开展的工作进行了展望,以期为实现对其有效管理和利用提供参考。     

金佛山自然保护区外来入侵植物种及其分布情况

生物入侵对全球的生物多样性造成了严重威胁。自然保护区是保护生物多样性的重要基地,因此,自然保护区的生物入侵现状如何备受关注。本研究以金佛山国家一级自然保护区为研究区域,采用样方法和野外踏勘法对金佛山自然保护区的外来植物进行了调查,初步调查结果如下:1)在金佛山共发现56种外来植物种,主要是草本类植物,且多呈零星分布,绝大部分外来植物与本地植物一样仅仅作为一种可利用资源出现,而且没有出现明显的相互竞争,但五节芒具有突出的入侵分布特征;2)56种外来植物中有31种是有意引进的,占入侵种总数的55%;15种是自然入侵的,占27%;有9种是入侵来源不明的,占16%;1种是伴随其他物种无意引进的,占2%。而目前危害面积最大的五节芒就是入侵通道不明的外来植物种;3)调查的样方中外来植物的出现频度与干扰程度相关,干扰越严重的,出现外来植物种的几率越大,踏勘也呈现了同样的规律。     

Invasion is Contingent on Species Assemblage and Invasive Species Identity in Experimental Rehabilitation Plots

Ecological studies often suggest that diverse communities are most resistant to invasion by exotic plants, but relatively few local species may be available to a rehabilitation practitioner. We examine the ability of monocultures and diverse assemblages to resist invasion by an exotic annual grass (cheatgrass) and an exotic biennial forb (dyer's woad) in experimental rehabilitation plots. We constructed seven assemblages that included three monocultures of grass, forb, or shrub; three four-species mixtures of grasses, forbs, or shrubs; and a three-species mixture of one species from each growth form in an experimental field setting to test resistance to invasion. Assemblages were seeded with cheatgrass and dyer's woad for two consecutive years and quantified as biomass and density of individuals from each exotic species. Soil NO₃^- and leaf-area index were examined as predictors of invasive plant abundance. Cheatgrass invasion was greatest in forb and shrub assemblages, and least in mixed grass or grass monoculture; dyer's woad invasion was greatest into mixed grass or grass monoculture, but least into monoculture or mixed-species assemblages composed of forbs or shrubs. The community composed of grasses, forbs, and shrubs suppressed invasion by both species. Consequently, assemblages were most resistant to invasion by species of the same growth form. Moreover, these monocultures and mixtures were generally similar in conferring resistance to invasion, but a monoculture of big sagebrush was more resistant than a mixture of shrubs. Soil NO₃^- was correlated with invasion by cheatgrass, whereas LAI was correlated with invasion by dyer's woad, suggesting these species were more limited by belowground and aboveground resources, respectively. Overall, increasing diversity with limited species did not necessarily enhance resistance to invasion.     

北方农牧交错带草木犀属外来植物沿公路分布和扩展的影响因素探讨

公路的建设给原有的生态系统带来人为干扰和影响,公路建筑材料的运输给外来植物的引入带来风险,公路修建以及环境因子则影响外来物种的建植和扩繁。选择北方农牧交错带典型的柏油公路,对草木犀属（Melilotus）外来植物沿公路的入侵状况进行样带调查,以探讨外来植物沿公路分布和扩散的影响因素。结果表明：公路两侧的土地利用方式是影响草木犀属植物分布的主要因素,路旁有农田的地段中,草木犀属植物的分布密度要显著大于有草地的地段（P<0.05）。距离则是影响草木犀属植物分布密度的重要因素,随着从路基到路旁生境距离的增加,草木犀属的分布密度呈显著下降趋势（P<0.05）。此外,公路的走向也影响草木犀属植物的分布,草木犀属在下风向的分布密度显著大于上风向的分布密度（P<0.05）;公路两旁高大树木的遮阴同样影响草木犀属植物沿公路的分布,遮阴环境影响草木犀属一年生植物的密度（P<0.05）,但对于二年生植株没有显著影响。