艾比湖湿地自然保护区荒漠植物群落物种多样性研究

以重要值为测度指标,选择反映群落物种多样性、丰富度、优势度和均匀度的6个测定指数对艾比湖湿地自然保护区荒漠植物群落物种多样性进行了研究。结果表明:在整个研究区荒漠植物群落中,盐穗木、盐节木、白梭梭、梭梭和盐爪爪等物种有较高的重要值,草本的重要值较低。各群落类型的物种多样性指数的顺序为:白梭梭>胡杨>盐穗木>盐豆木>罗布麻>琵琶柴>花花柴>白刺>柽柳>白麻>芦苇>芨芨草>梭梭>骆驼刺>甘草>盐节木。     

汾河水库湿地植物区系组成及物种多样性研究

在野外78个植物样方调查数据的基础上,采用吴征镒、王荷生区系分析方法和丰富度指数(Ma、Pa)、均匀度指数(JP、EA)和综合多样性指数(H'、DS)分析方法,对汾河水库湿地植被物种区系成分和多样性进行了研究。结果表明:1)该湿地共有湿地植物72种,分别隶属于28科58属。优势科、单种属现象明显,其中以菊科(Compositae)种数为最多,植物水分生态类型多样,中生植物占有明显优势;2)植物分布区系类型多样,以世界分布属为主,占属总数的34.48%,反映了该湿地植被的隐域性特征明显,其次是北温带分布占总属数的24.14%,显示北温带区系的区域性;3)在研究区0～400m的范围内,随着离水库边缘距离的递增,物种多样性呈先增高后降低的趋势,且土壤水分条件是影响研究区物种多样性变化的主要环境因子。     

奇台荒漠草地自然保护区典型植物群落物种多样性分析

以重要值为测度指标,选择反映群落物种多样性、丰富度、优势度和均匀度的7个测定指数对奇台荒漠草地自然保护区荒漠植物群落物种多样性进行了研究。结果表明:在整个研究区荒漠植物群落中,白梭梭、梭梭、碱蓬、琵琶柴、沙蓬、驼绒藜和沙漠娟蒿等物种有较高的重要值。依据群落外貌结构和植物种类组成等特征,按照样方中建群种和优势种的重要值,将研究区植物划分为14个典型群落,各群落类型的物种多样性指数(Shannon-wiener指数H′)的顺序为:梭梭+角果藜(2.0740)>白梭梭+驼绒藜(1.9037)>白梭梭+羽毛三芒草(1.8909)>梭梭+芦苇(1.8474)>梭梭+雾冰藜(1.7434)>芦苇+猪毛菜(1.7278)>梭梭+白茎娟蒿(1.6723)>白梭梭+琵琶柴(1.5410)>白梭梭+沙蓬(1.4886)>白梭梭+假木贼(1.4530)>梭梭+碱蓬(1.4437)>白梭梭+刺木蓼(1.4277)>白梭梭+角果藜(1.3637)>白梭梭+沙漠娟蒿(1.3362)。     

西北半干旱区湿地生态系统植物群落多样性的研究

为了研究西北半干旱区湿地植被多样性差异,以宁夏盐池县四儿滩湿地为例,采用样线法,从湿地中央辐射向四个方向,布设东、南、西、北四条样线,共取样方88个,主要调查植被的盖度、高度、频度、株数等,计算每种植被的重要值,运用SPSS软件进行聚类,分析了该湿地的植被组成和群落特征。采用Shannon-Wiener指数、Simpson指数、群落均匀度指数和丰富度指数对植物多样性进行研究分析,并结合多年的气象数据,分析结果为:碱蓬和盐爪爪群落为湿生带的代表群落,白刺和沙鞭群落与芨芨草、猪毛蒿和苦豆子群落为交错带的代表群落,阿尔泰狗哇花、赖草和砂兰刺头群落为旱生带代表群落;四儿滩湿地四条样线之间植被多样性的差异主要受四儿滩湿地本身的地理环境和人类生产活动的影响。年际植被多样性差异主要受月降雨量分配的影响。     

艾比湖湿地自然保护区典型群落物种多样性分析

采用Shannon-Wiener和Simpson物种多样性指数,Margalef和Gleason丰富度指数,均匀度指数和生态优势度指数对艾比湖湿地自然保护区典型群落物种多样性进行分析研究。结果表明:植物群落在垂直结构上的多样性分布是灌木和乔木的物种均匀度、多样性和丰富度指数的变化趋势均大于草本,而生态优势度指数则与其相反,表现出单一的植物群落结构,说明艾比湖自然保护区典型群落在多个层次上物种的数量和分布与该地环境条件成正相关,即该区植物种类少、盖度低,生物资源丰富度十分匮乏。     

新疆玛纳斯麻黄生态保护区植物群落特征及其多样性分析

以重要值为测度指标,选择反映群落物种多样性、丰富度和均匀度的7个测定指数,对玛纳斯平原林场麻黄生态保护区植物群落的物种多样性研究。结果表明:在整个研究区荒漠植物群落中,中麻黄、百刺、蛇麻黄和骆驼蓬等物种有较高的重要值,而草本植物的重要值较低;麻黄种群在样地中属优势种,且进一步发展的趋势明显,减少人为干扰,麻黄种群自然恢复较快。     

克拉玛依植物群落物种多样性研究

根据30个样地102个样方的调查资料,采用Simpson多样性指数、Shannon-Wiener多样性指数、Gleason丰富度指数[17]、Simpson优势度指数与Pielou均匀度指数[16]对克拉玛依植物群落进行研究。研究结果表明:克拉玛依植物群落结构简单、物种稀少,群落物种多样性水平较低,群落多样性指数的顺序为:胡杨群落﹥柽柳群落﹥梭梭群落﹥琵琶柴群落﹥芦苇群落﹥假木贼群落﹥猪毛菜群落﹥盐节木群落﹥碱蓬+麻黄群落﹥盐穗木群落。随着水分与土壤盐碱度的变化,群落物种多样性出现相应的变化趋势:乔木群落﹥灌木群落﹥草本群落。     

鄂尔多斯高原盐沼湿地浮游植物的多样性与评价

浮游植物是重要的湿地资源,其种类、数量、生长变化、种群结构与分布直接影响湿地生态系统的功能和效益。沙漠盐沼湿地生态系统中浮游植物多样性迄今未见报道。文中在2006、2007年每年的4-10月对鄂尔多斯高原盐沼湿地的桃-阿海子和红碱淖尔湖泊浮游植物多样性进行调查研究。调查方法依据《内陆水域渔业自然资源调查手册》进行,浮游植物多样性评价采用Pielou均匀度、Margalef丰度和Shannon-Weaver多样性指数计算。结果表明:2006、2007年红碱淖尔浮游植物分别为15种和18种,发现的藻类除半咸水或盐水种之外,大多数是淡水普生性的广盐种或喜盐种,由于碱度高,Ca2+含量极低,浮游植物的生物量不高,并且5.8g/L和6.2g/L的盐度恰好处于5~8g/L的水生生物耐盐性的极限范围内,生物种类较少。桃-阿海子两年分别发现4种、2种,主要是盐藻、螺旋藻等较典型的盐水种以及耐盐种和喜盐种。盐度不是决定浮游植物种类组成和分布的唯一生态因子;在所调查的湿地中,Na+摩尔百分数含量达43.3-48.1%,CO32-+HCO3-达12.7-26.3%,碳酸钠对硅藻具有毒性,随盐度升高毒性加剧,在桃-阿海子未检出硅藻,红碱淖尔也仅有三种;离子系数(M/D)是一项重要的生态指标,桃-阿海子浮游植物种类少于相似盐度的尕海内湖和夏日淖、桑根达莱淖,是因为湖水的离子系数太大。综合来看,浮游植物多样性受众多生态因子共同影响。     

干旱区山地植物群落物种多样性与生产力关系分析

在我国典型干旱山地系统中,对3个典型生境类型(沙化草地、土质阴坡、石质阴坡)的植物群落进行取样,分析植物群落多样性与其生产力关系。结果表明,3个生境条件下,3种多样性指数(Shannon,wienmer指数、Simpson指数、Margalef丰富度指数)与生产力的线性关系拟合结果较好,说明干旱山地植物物种多样性与其生产力关系是线性关系。该地区处于长期过度放牧利用状态下,因此,物种多样性与生产力的线性关系是生境资源限制和长期过度干扰共同作用的结果。     

北京地区外来入侵生物种类调查初报

通过调查研究和查找有关文献资料明确,北京地区外来入侵生物种类有动物11种,植物23种,列出了其主要的分布范围及其危害,讨论了外来入侵生物的防治对策。对一些危害严重的种类应迅速根除或控制,在引种前或应用前应对有潜在危险的种类进行科学的风险评估,对北京周边地区发生的入侵生物种类应该严格监管和防范。     

中国草地外来生物入侵现状与防控建议

草地是我国生态系统的重要组成部分,更是我国畜牧业发展的重要物质基础。外来生物入侵迫使我国脆弱的草地生态系统雪上加霜,严重威胁生态安全、生物安全和畜牧业高质量发展。本文全面总结了我国草地外来入侵生物的物种组成、来源及其危害,系统分析了重要外来生物的入侵扩散机制和防控现状。根据文献统计,我国草地外来入侵生物共有176种,包括入侵植物145种,入侵动物25种,入侵微生物6种,它们主要来源于北美洲。大量外来生物入侵直接影响了草地物种多样性,破坏了草地生态系统的结构和功能,严重威胁人畜健康和社会经济可持续发展。草地外来生物成功入侵与其自身的生物学生态学特性、与本地种的相互作用和环境条件的可入侵性密切相关,虽然目前利用化学防治、生物防治和生态控制等技术可以进行有效防治,但防控的实效性、可持续性差,建议建立基于智能识别与监测预警,集成应急阻截和持续减灾等关键技术的系统解决方案,实现外来入侵物种早发现、早治理,为快速抑制扩散蔓延和区域持续减灾提供科技支撑。     

Climate warming alters competition between two highly invasive alien plant species and dominant native competitors

Biological invasions and climate warming are two major threats to the world's biodiversity. To date, their impacts have largely been considered independently, despite indications that climate warming may increase the success of many invasive alien species. We therefore set up an experiment to study competition between native and invasive alien plant species and the effects of climate warming thereon. Two highly invasive alien plant species in Belgium, each with a native competitor that dominated in invaded sites, were grown either together (1:1 mixtures) or in isolation (monocultures) at ambient and elevated temperature (+3°C) in climate‐controlled chambers. To detect possible mechanisms underlying the effects of competition and elevated temperature, we conducted a combined growth and nitrogen uptake analysis. In one pair, Senecio inaequidens – Plantago lanceolata (alien invasive – native), the alien species dominated in mixture, while in the other pair, Solidago gigantea – Epilobium hirsutum, the native species dominated. Climate warming reduced the invader dominance in the first species pair, but stimulated the suppressed invader in the latter. Many of the biomass responses for these two species pairs could be traced to the root‐specific nitrogen uptake capacity. The responses of the native‐invasive interaction to warming could not always be extrapolated from the monoculture responses, pointing to the necessity for experiments that take into account species interactions.     

高山草地蝗虫群落生物多样性和空间聚集强度对植物群落的响应

为明确高山草地蝗虫群落生物多样性和空间聚集强度变化及其对植物群落的响应,在位于甘肃省祁连山中段北坡的研究区调查温性草原、山地草甸和高寒草甸3类草地中的蝗虫种类和数量,对不同蝗虫群落进行生物多样性分析,并观察不同蝗虫种群的聚集程度.结果 显示,共捕获蝗虫15种,8月温性草原内蝗虫虫口密度最大,为8.17头/m2,且此时S...     

Outbreak of a new alien invasive plant Salvia reflexa in north‐east China

The establishment of invasive species is widely recognised as a pivotal issue in the preservation of biodiversity. Salvia reflexa, a species native to the south‐central United States and Mexico, has been widely introduced in Argentina, Australia, New Zealand and Japan. In China, the first population of this plant was found growing adjacent to a grain depot in Shahai village, Jianping County, Liaoning Province, on 25 July 2007. Since the grain depot imported foodstuffs from regions where the plant is native, we infer that S. reflexa was introduced into China via imported foodstuff in the early to mid‐2000s. Based on field observations, at least seven populations of this plant were observed in north‐east China. The plants displayed vigorous growth in midsummer and produced prolific seeds to overcome the cold environment in winter. Salvia reflexa occurred in both dense monocultures and in mixed stands with native plants. In order to validate a system for recognising and categorising non‐native plants in China, the Australian Weed Risk Assessment system was used to assess the invasiveness status of 19 exotic and 16 native plants in north‐east China. Salvia reflexa exhibited a high score of 10, suggesting it is a potentially pernicious alien invasive plant. Although the current distribution of S. reflexa is restricted to Liaoning province and thus far has limited impact on local environments, local regulatory authorities should pay close attention to this plant and take measures to stop its expansion. This is the first time that an invasive plant from the Lamiaceae (mint family) has been documented from cold environments in China.     

Performance of the invasive Eupatorium catarium and Ageratum conyzoides in comparison with a common native plant under varying levels of light and moisture

Invasive alien plants are often found to be more plastic than the natives, which enable the former to outperform the native plants under some, or in a wide range, of environmental conditions. In addition, their performance under non‐competitive conditions might not predict their performance under competitive conditions. The performance of the recent invader, Eupatorium catarium, was compared with that of a historical invader, Ageratum conyzoides, and a common native plant, Vernonia cinerea, under varying levels of light and moisture with and without competition. When grown alone and in response to decreases in light levels, E. catarium and V. cinerea were more plastic in their root‐to‐shoot ratio than A. conyzoides, while V. cinerea was more plastic in its specific leaf area (SLA) than E. catarium and A. conyzoides. Eupatorium catarium was more plastic than A. conyzoides and V. cinerea in the SLA in response to the drought treatment. However, these differences in trait plasticities did not lead to a difference in biomass production under each light and moisture treatment combination. When E. catarium was competing with either A. conyzoides or V. cinerea, the interacting species also did not differ in their biomass production and relative interaction intensity under each light and moisture treatment combination. These results indicate that the two invasive species and the native plant do not differ in their performance under relatively low soil nutrient conditions, regardless of the moisture, light and competition treatments that are imposed. Therefore, E. catarium and A. conyzoides cannot outperform V. cinerea under low nutrient conditions, regardless of the light and water availability.     

Quick assessment of the invasiveness of non‐native plant species by using eco‐physiological parameters in Tram Chim National Park,Vietnam

Using eco‐physiological parameters, a quick assessment of the invasiveness of non‐native plant species was conducted in Tram Chim National Park, a Ramsar site that is located in the Mekong River Delta region of Vietnam. An investigation of non‐native species and a vegetation analysis were carried out along 25 line transects and in 50 quadrats by using the Braun–Blanquet method. The researchers identified 84 non‐native plant species but only 31 species were naturalized in the wetland ecosystems. Twenty of those 31 species with a high importance value index were screened by using a parameter that was obtained from chlorophyll a fluorescence measurement, the performance index. Five species were identified as invasive and five others were predicted to be potentially invasive. The first group of five species were: M imosa pigra, P anicum repens, E ichhornia crassipes, S alvinia cucullata and L eersia hexandra, which already had been confirmed as important weeds in the national park by previous studies. From the second group, two species ( L udwigia hyssopifolia and S accharum spontaneum) already are becoming prominent species in some locations. The three remaining species ( M onochoria hastata, I sachne globosa and M arsilea quadrifolia) are likely to become invasive in the future.     

长白山植物群落谱系结构及环境因子对其的影响

以往在长白山植物群落生态学的研究中极少考虑物种间的亲缘关系。由物种亲缘关系所度量的群落谱系结构可以反映进化与生态过程对群落结构的影响,因而可以从全新的角度来了解群落构建的成因。文中研究以长白山76块样地为基础,分析了群落的谱系结构以及环境因子对其所造成的影响,结果显示:各样地、各群落类型均表现出一定的谱系结构,表明长白山植物群落构建过程主要是受生态位机制的作用;海拔、林分郁闭度、坡度及土壤腐殖质厚度与谱系结构存在显著的相关性。进一步将群落谱系结构结合环境因子的分布状态进行分析可以推测,环境压力作为生境过滤的形式是高山苔原以及岳桦林群落构建的最主要驱动力;干扰与环境压力对低海拔阔叶林群落构建起到重要作用;环境压力的缺失使得竞争作用放大,这成为决定阔叶红松林群落结构的主要方面。     

我国主要的外来恶性杂草及防治技术

外来恶性杂草具有极强的适应能力、竞争能力和惊人的繁殖能力,一旦入侵,能排挤当地物种,蔓延迅速,很快成为优势种群。我国主要恶性杂草有紫茎泽兰、香泽兰、蔓泽兰、凤眼蓝、喜旱莲子草、刺花莲子草、大米草、豚草等。防治这些外来恶性杂草主要措施可以采用加强检疫、替代控制、农业及机械防除、人工防除、生物防治、化学防除,以及研究有害杂草的利用等手段进行综合治理。     

农业外来生物入侵种研究现状与发展趋势

目前国际上对外来生物入侵种的研究主要在个体水平上研究外来种对新环境的进化与适应,本地种对生物入侵后发生的进化调整;种群和群落水平上研究外来种的定居、潜伏、竞争和暴发;生态系统水平上研究生境的可入侵性和外来种对生态系统结构和功能的影响等几个方面。风险分析标准化与定量化、检疫鉴定快速化、除害技术安全化、信息管理全球化是全世界对外来物种入侵管理与科研的焦点问题。本文依据外来物种入侵的形成和扩散暴发过程,提出了超前预防和综合管理等未来需要解决的关键问题。