Typification of species of Codium (Bryopsidales, Chlorophyta) described by Okamura

Type specimens of six species of Codium described by Okamura are illustrated, including the holotype of Codium barbatum and lectotypes of Codium coactum, Codium intricatum, Codium pugniforme, Codium saccatum, and Codium subtubulosum. All species are currently recognized except C. pugniforme, which is indistinguishable from the previously described Codium spongiosum Harvey, Codium subtubulosum was abandoned by Okamura in favor of the previously described Codium divaricatum Holmes, but because of the prior existence of C. divaricatum (C. Agardh) Biasoletto, C. subtubulosum is the correct name for this species.     

化学通讯在松材线虫侵染和扩散中的作用

松材线虫为外来入侵种 ,由其引起的松材线虫病正在我国迅速扩散蔓延 ,造成我国部分地区松林资源的毁灭性破坏。松材线虫病的发生和流行与媒介天牛、寄主植物、共生真菌和细菌密切相关 ,松材线虫 -墨天牛 -松树 -共生微生物之间存在着广泛的化学联系 ,它们通过化学互作 ,调控松材线虫的行为 ,影响松材线虫的侵染和扩散     

不受欢迎的生物多样性：香港的外来植物物种

香港早在19世纪中叶开始就有外来植物入侵的记录,迄今为止,已发现多达238种已归化的外来或怀疑为外来的植物,其中又以薇甘菊（Mikania micrantha)、五爪金龙（Ipomoea cairica)、假臭草（Eupatorium catarium)、大黍（Panicum maximum)等最常见,外来植物最常见于受人为干扰的生境,例如荒废农田及路旁等,而较少在天然林地生境及贫瘠的灌草丛中发现,外来植物的对本地生态系统的影响主要局限于低地生境,它们常形成单优种群,减少了生境及贫瘠的灌草丛中发现,外来植物对本地生态系统的影响主要局限于低地生境,它们常形成单优种群,减少少了生境及动植物的多样性,外来动物对香港原生植物影响最大的是于20世纪70年代入侵的松树线虫（Bur-saphelenchus xylophilus)。外来的脊椎动物也有可能对香港的植物被演替产生影响,目前香港的外来植物当中,有些在大陆较少分布或没有记录,作为华南最大的港口,香港对外来物种的引入扮演着重要的角色,因此制定控制外来种在香港及华南地区的引入及传播的政策及措施非常重要。     

The global spread and invasion capacities of alien ants

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江苏省外来种子植物的初步调查和分析

对江苏省外来种子植物的种类、来源地及分布状况进行了初步调查统计。调查结果显示,江苏省共有外来种子植物393种,大多数来源于欧洲和美洲,主要通过有意引种和无意引入2种方式引入。有意引种的栽培植物有276种,其中观赏植物132种、蔬菜46种、林木35种、工业原料植物17种、药用植物12种、牧草植物11种、粮食作物11种、果树7种以及油料作物5种。另外,外来种子植物中有逃逸种62种、归化种22种、入侵种33种;81．8％的入侵种在江苏全省均有分布;入侵种以菊科（Compositae）和禾本科（Poaceae）植物为主,分别有11种和7种。在此调查结果基础上,对江苏省外来种子植物的分类和危害进行了讨论,并对江苏省外来物种的利用和管理提出了一些建议。     

浙江新外来入侵植物——合被苋

合被苋Amaranthus polygonoides L.原产加勒比海岛、美国、墨西哥等地,是新近传入浙江的外来植物。本文报道合被苋的植物学和生态学特性,介绍其在国内外分布和国内蔓延情况,为该种的早期控制提供基础资料。     

外来种入侵的生物学与生态学基础的若干问题

外来物种的入侵及其所造成的危害已越来越为人们所认识。一个外来物种入侵一个新的生境无疑要具备一定的条件 ,尽管目前对这种条件的研究还只是初步的。首先从其自身来说 ,需要有足够的入侵性 ,这可以认为是入侵种的生物学基础 ,可能表现为具有多倍性、一定的遗传变异、杂合性或表型可塑性 ,以及不同的交配系统等 ;其次一个物种的入侵成功还取决于入侵生境的可入侵性 ,这可以认为是入侵种的生态学基础 ,而新的种间关系的形成 ,尤其是入侵种与其他种类的互惠共生关系的建成是关键。本文主要介绍了有关入侵种的生物学和生态学基础中的一些最新进展 ,希望有助于我国学者对相关研究内容的开展以及对有害外来种入侵的防治     

Invertebrate communities associated with a native (Vallisneria americana) and an alien (Trapa natans) macrophyte in a large river

1. We used a corer and a Downing box sampler to sample macroinvertebrates living on and beneath the introduced Trapa natans and the native Vallisneria americana in the freshwater tidal Hudson River, New York. 2. Densities of macroinvertebrates were higher in Trapa than in Vallisneria, and higher in the interior of plant beds than at their edges. These effects were largely a result of high plant biomass in Trapa beds and in bed interiors (the plants have similar surface area per unit mass). 3. The composition of both epiphytic and benthic macroinvertebrates differed distinctly between Trapa and Vallisneria, and also seasonally. 4. These compositional differences were not easily interpretable as rising from possible differences in oxygen concentrations, fish predation, or water circulation in the two macrophytes. 5. Sida crystallina (Cladocera) collected from Trapa contained more haemoglobin than those collected from Vallisneria. 6. The replacement of Vallisneria by Trapa in the Hudson probably increased system‐wide biodiversity and food for fish, although macroinvertebrates in Trapa beds may not be readily available to fish because of low oxygen concentration there.     

Weed macaques: The evolutionary implications of macaque feeding ecology

Patterns of feeding ecology among the living macaques conform poorly with recognized phyletic distinctions within the genus because there is an important ecological division which cross-cuts phyletic groupings. This division, between weed species and non-weed species, is based on the differing abilities of macaques to tolerate and even prosper in close association with human settlements. Based on available information about their ecology in the wild, we tentatively assign macaque species to these two categories. Finally, we consider the implications of our argument for scenarios of the initial spread of the macaques.     

Inviting trouble: Introduced pasture species in northern Australia

Abstract I surveyed the history of exotic pasture introductions in northern Australia to compare the rate of introduction of useful species with that of weeds. Between 1947 and 1985, 463 exotic grasses and legumes in at least 2033 accessions were intentionally introduced into the region, the grasses predominantly from Africa, and the legumes from Central and South America. Of these, only 21 (5%) came to be recommended as useful, while 60 (13%) became listed as weeds. Seventeen of the useful plants were in fact also weeds, leaving only 4 species (<1%) that were useful without causing weed problems. They were far outnumbered by the 43 species (9%) that were weeds but had no recorded use. Of the 60 weeds, 21 were weeds of cropping, 20 were weeds of conservation and 19 were weeds of both sectors. Thirteen were listed as major crop weeds. Growth rate, maximum height, seed size, and continent of origin were unrelated to weediness. Good predictors of weediness were whether a plant was useful, a good performer in trials, or persisted at a field site. In addition, grasses were more likely, and legumes less likely, to be weedy than expected. It is argued that a new form of assessment is required before an exotic plant species is released into the Australian environment as a pasture plant. This would recognize that a successful introduction is almost certain to become a weed in some situations, and would attempt to assess the net national benefit of the proposed introduction.     

利用传统生物防治控制外来杂草的入侵

随着国际贸易的日益频繁,外来有害植物入侵,严重威胁我国的自然环境和生物多样性。利用从原产地引入食性较专一的天敌来控制外来杂草是杂草生物防治的主要方式之一,有保护环境一劳永逸的效果。简要介绍了国际生物防治概况,统计表明全世界至少有133种目标杂草进行生物防治,主要分布在菊科、仙人掌科和含羞草科,63科369种无脊椎动物和真菌作为杂草生物防治的天敌,利用最多的天敌是鞘翅目象甲科和叶甲科昆虫,其中大多数项目是治理外来杂草的。杂草生物防治最活跃的国家依次为美国、澳大利亚、南非、加拿大和新西兰。重点论述了利用传统生物防治方法防治外来杂草的经典项目、国内外研究概况,以及目前面临的问题和应用前景。我国杂草生物防治起步晚,传统杂草生防的目标杂草有4种,紫茎泽兰、空心莲子草、豚草和水葫芦,其中,空心莲子草的生物防治获得成功。共引进天敌14种,输出天敌23种,与世界上生物防治先进的国家比尚有距离。中国应充分借鉴国际成功经验,对外来杂草开展生物防治。中国的生物多样性在世界上占有十分独特的地位,将在生物多样性保护中发挥重要作用。