不同光照和水分条件对土著灾变种金钟藤形态性状和化感作用的影响

金钟藤为海南原产,近20年来种群数量迅速增多,并对许多次生林、人工林和灌木林造成严重危害。金钟藤种群成灾的生境或区域有不同的光照和水分条件,而灾变种往往通过较高的表型可塑性来适应多样的生境条件。为揭示土著灾变种金钟藤适应多样生境条件的生理生态机制,本文通过温室盆栽试验研究了不同光照和水分条件对金钟藤生长、形态性状及其可塑性、化感作用的影响。结果表明,高光干旱条件下金钟藤生物量有所降低。在低光下,金钟藤增加了茎总长度、比茎长、比叶面积,降低了根冠比。这些形态性状的表型可塑性指数平均为0.36。高光干旱生长条件下,金钟藤叶片水浸液对生菜种子萌发和芽长生长的抑制作用较低,可能是因为在这种胁迫条件下,金钟藤降低了对竞争(化感)的资源投入。形态性状的可塑性可能促进了金钟藤在林下低光环境下更好的捕获光能和快速生长至冠层,而化感作用的可塑性说明金钟藤可能通过调节对竞争(化感)的资源投入来适应多样的水分条件。金钟藤在形态性状和化感作用方面的可塑性可能是其适应多样生境条件并爆发成灾的生理生态机制之一。     

中国网藤蕨属一新异名

报道了广西蕨类植物一新记录属——藤蕨科网藤蕨属LomagrammaJ.Sm.;经野外观察及标本研究,将云南网藤蕨L.yunnanensis Ching处理为网藤蕨L.matthewii(Ching)Holttum的异名,并绘制了墨线图以便于分类识别。     

Lomagramma yunnanensis Ching, a new synonym from China

报道了广西蕨类植物一新记录属--藤蕨科网藤蕨属Lomagramma J.Sm.;经野外观察及标本研究,将云南网藤蕨L.yunnanensis Ching处理为网藤蕨L.matthewii(Ching)Holttum的异名,并绘制了墨线图以便于分类识别.     

林业有害植物金钟藤新枝在海南的月生长动态

【背景】近20多年来,金钟藤在海南和广东异常快速生长,对生物多样性和林业生产破坏严重。观测金钟藤的月生长动态,了解其在海南的生长量,能够为金钟藤的合理防治提供参考。【方法】采用定点定时观测法,对海南3个市县3种不同生境的金钟藤新枝的月生长量进行测定。【结果】金钟藤在海南全年可生长,一新枝月平均生长134 cm,全年累计平均生长1607 cm。金钟藤全年有2个生长高峰期,分别在4月和9月,其中4月平均生长206 cm,9月187 cm。金钟藤在11月生长量最小,平均生长86 cm。金钟藤在1—9月生长较快,一新枝累计平均生长1326 cm,占全年生长量的82.5%;在10月至12月生长缓慢,一新枝累计平均生长281 cm,占全年生长量的17.5%。不同生境之间的金钟藤生长有极显著差异,月平均生长量从高到低顺序为定安188 cm白沙131 cm五指山83 cm。金钟藤种子在3—7月均可萌发,花果期在4—7月。在海南月平均温度17~28℃、月平均降雨量28~396 mm的自然环境范围内,金钟藤的生长量与温度和降雨量没有显著相关性。【结论与意义】金钟藤在海南光照充足的生境里快速生长扩散,月平均生长量高达188 cm,其生长与生境、海拔和植被密切相关。     

金钟藤种子低萌发率原因探讨

金钟藤种子在室内萌发率很低,为进一步探讨金钟藤种子的特性,阐明其种子萌发率低的主要原因,对金钟藤种皮的透水性、种子解剖结构、种子活力和种子内源抑制物的生物测定进行了研究。结果表明:金钟藤种皮透水性较差,完整种子比破皮种子吸水达到最高水平慢38h;种子空瘪粒多,占所有种子的30%;种子活力较低,平均活力仅为35%;金钟藤种子甲醇粗提液对白菜种子萌发率、根长和芽长均有较强的抑制作用,其浸提液浓度在25mg/mL时,严重抑制白菜种子萌发和生长,即金钟藤种子内部含有较高的内源抑制物质。金钟藤种子萌发率低,表明其近年来突发性蔓延成灾主要不是由种子生成新个体造成的,导致其蔓延成灾的关键因素还需要进一步深入研究。     

金钟藤叶片的气体交换特性

用LI-6400便携式光合测定系统(Li-CorInc.,USA)对广州林区新发现的入侵杂草金钟藤(Merremiaboisiana)叶片的气体交换进行了测定。结果表明(1)净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(E)的日变化均表现为单峰型曲线,中午金钟藤未出现光合作用抑制;最大光合速率可达20μmolCO2.m-2.s-1左右,Pn日平均值为8.8±0.75μmolCO2.m-2.s-1。(2)金钟藤光合作用的光饱和点较高,为1000~1200μmolphotons.m-2.s-1,表现出比较典型的阳生植物的特性。结果表明,金钟藤在自然环境中具有快速生长的特性可能与其较强和较稳定的光合能力有关。研究的初步结果对了解金钟藤迅速生长、具有高生产力和强大入侵力的原因提供了进一步深入探讨的思路和基础数据。     

金钟藤和葛藤在干旱与复水条件下的生理比较

对外来入侵种金钟藤和本地种葛藤进行干旱胁迫和水分恢复处理,比较了两种植物抗氧化酶(SOD、CAT)活性、丙二醛(MDA)含量及叶绿素荧光参数的变化。研究表明,干旱胁迫下两种植物SOD、CAT活性均高于复水后,金钟藤高于相同处理下的葛藤;金钟藤在干旱与复水条件下的MDA含量无差异,而葛藤干旱下高于复水后,不同处理下葛藤均高于金钟藤;干旱条件下金钟藤比葛藤有更强的抗氧化能力,膜脂过氧化水平明显较低,MDA与SOD、CAT呈明显的负相关。两种植物在复水后Fv/Fm、ETR与ΦPSⅡ值均显著高于干旱时,葛藤变化程度略大于金钟藤。复水后金钟藤的NPQ值增加而葛藤降低,且干旱时葛藤大于金钟藤,复水后金钟藤大于葛藤。综合比较,金钟藤比葛藤对干旱的生理适应能力强,这可能是其入侵性的重要特征。     

金钟藤入侵群落的种间联结及生态位特征

金钟藤(Decalobanthus boisianus)是林业有害植物, 其暴发生长和扩散对森林生态系统造成了严重破坏。本文以海南岛48个金钟藤典型分布群落为研究对象, 用方差比率法和贡献定律法探究群落的稳定性; 用χ ²统计量、联结系数(AC)、共同出现百分率(PC)、Ochiai指数和Dice指数分析金钟藤与伴生物种的种间联结关系; 用生态位宽度、生态位相似性系数和生态位重叠指数研究群落中各物种的生态位特征, 以期为金钟藤生物防治的植物物种筛选提供借鉴。结果表明: (1)金钟藤所在48个群落共有156种伴生植物, 其中大戟科、茜草科、桑科、无患子科和樟科植物占优势; (2)群落中优势物种呈正联结关系, 植物种类累积倒数百分比与累积相对频度交点坐标为(44.53, 55.47), 远离稳定交点坐标(20, 80), 说明群落处于不稳定状态; (3)金钟藤与芳槁润楠(Machilus suaveolens)、黄椿木姜子(Litsea variabilis)、岭南山竹子(Garcinia oblongifolia)、显脉杜英(Elaeocarpus dubius)、鸭脚木(Schefflera octophylla)和银柴(Aporusa dioica)都紧密关联, 说明金钟藤与这些物种的资源利用方式较相似; (4)金钟藤的生态位宽度最大, 与伴生物种间的生态位重叠度较高, 但伴生物种间的生态位重叠度较低。金钟藤的入侵导致群落处于不稳定状态, 并与伴生物种间存在激烈的竞争关系。因此, 建议在金钟藤已入侵的群落中大量栽种芳槁润楠、黄椿木姜子、显脉杜英、鸭脚木和银柴, 以遏制其蔓延; 大量栽种翻白叶树(Pterospermum heterophyllum)、海南菜豆树(Radermachera hainanensis)、九节(Psychotria rubra)和肉实树(Sarcosperma laurinum)用于金钟藤入侵群落的植被恢复。     

中国清风藤属Sabia Colebr.(清风藤科)的订正

归并了清风藤属5个名称,Sabia campanulata Wall.ex Roxb.var,kingiana Nayar et Majumder处理为S.campanulata Wall.ex Roxb。的异名,S.metcalfiana L.Chen处理为S.leptandra Hook.f.et Thoms.的异名,S.longruiensis X.X.Chen et D.R,Ling和S.swinhoei Hemsl.ex Forbes et Hemsl.ex FOrb.et Hemsl。的异名,S.nervosa Chun ex Y.F.Wu处理为S.coriacea Rehd.et Wils.的异名,订正了缅甸清风藤S.burmania L.chen在中国有分布的错误报道。     

五指山市金钟藤种群分布格局分析

在五指山市金钟藤生长区域内选取3 个样地对其分布格局进行野外调查分析。利用方差/均值比率法计算得到, A1 和A3 样地金钟藤种群呈集群分布, 而A2 样地金钟藤种群呈随机分布。此外, 通过聚集强度指数分析发现, A1、A3 样地金钟藤种群聚集强度指数I、m*/ x 、Iδ对1.0 的偏离程度明显, m*较大, 且K 值较小, 符合种群聚集分布特征。A2 样地金钟藤种群K 值较大, 其种群聚集强度指数I、m*/ x 、Iδ对1.0 的偏离程度不明显, 且m*较小, 符合种群随机分布特征。     

Seed, cutting and air-layering reproductive inefficiency of noxious woody vine Merremia biosiana and its implications for management strategy

Merremia boisiana (Gagnep) van Ooststr. is a noxious fast growing woody vine and is able to grow overtop other plants, causing the death of plants under-neath and forming monospecies stands. To formulate management responses, we assessed its seed and vegeta-tive reproduction efficacy through indoor and field experiments. The number of flowers counted from bagged infructescences in Guangzhou ranged from 25 to 172, with an average of 80.80. Counting the seeds of bagged infructescences had shown that there were only 1.58 hard testa seeds in each infructescence. Seed vitality tests using red ink indicated that only 68.6% of hard testa and filled seeds were viable. The emergence rate of scarified hard testa seeds in the sand bed was 31.96%. Under imitated natural conditions, 8% of hard testa seeds could germinate, and 9% still retained their germination potential in one year. Thus, seedlings should be monitored and removed in a timely fashion after any attempt of clearing. Moving soil or transplanting plant from infested patches should be strictly prohibited at least for several years. All considered, an infructescence contributed 0.3 seedlings. The investiga-tion in the field found no seedlings either inside or at the perimeter of the patch, suggesting scant expansion by means of seed dispersal. Therefore, the elimination effort could be focused on a relatively restricted scale of patches. Of 630 cuttings of young shoots, old shoots and old lying shoots with or without growth regulators, there were only four (or 0.63%) established individuals. Air-layering shoots all died in two months. Poor cuttings and air-layering reproduction indicated that regeneration from fragments of removed stems or accidentally dropped ones was quite unlikely, and thus mechanical removal was safe.     

赤车属(荨麻科)四种植物的订正

根据对赤车属植物标本的研究,将小赤车归并入短叶赤车,小异被赤车归并入异被赤车,海南赤车归并入滇南赤车,长茎赤车归并入赤车。     

Seed, cutting and air-layering reproductive inefficiency of noxious woody vine Merremia biosiana and its implications for management strategy

Merremia boisiana (Gagnep) van Ooststr. is a noxious fast growing woody vine and is able to grow overtop other plants, causing the death of plants underneath and forming monospecies stands. To formulate management responses, we assessed its seed and vegetative reproduction efficacy through indoor and field experiments. The number of flowers counted from bagged infructescences in Guangzhou ranged from 25 to 172, with an average of 80.80. Counting the seeds of bagged infructescences had shown that there were only 1.58 hard testa seeds in each infructescence. Seed vitality tests using red ink indicated that only 68.6% of hard testa and filled seeds were viable. The emergence rate of scarified hard testa seeds in the sand bed was 31.96%. Under imitated natural conditions, 8% of hard testa seeds could germinate, and 9% still retained their germination potential in one year. Thus, seedlings should be monitored and removed in a timely fashion after any attempt of clearing. Moving soil or transplanting plant from infested patches should be strictly prohibited at least for several years. All considered, an infructescence contributed 0.3 seedlings. The investigation in the field found no seedlings either inside or at the perimeter of the patch, suggesting scant expansion by means of seed dispersal. Therefore, the elimination effort could be focused on a relatively restricted scale of patches. Of 630 cuttings of young shoots, old shoots and old lying shoots with or without growth regulators, there were only four (or 0.63%) established individuals. Air-layering shoots all died in two months. Poor cuttings and air-layering reproduction indicated that regeneration from fragments of removed stems or accidentally dropped ones was quite unlikely, and thus mechanical removal was safe.     

值得注意的中国植物(续)

续报道了大戟科等 8个分类单位。大果留萼木 ( Blachia andamanica)为广东和海南的新记录 ;崖州留萼木 ( B.jatrophifolia)的新异名为 B.yaihsienensis;黄毛果巴豆 ( Croton lachynocarpusvar.kwangsiensis)是降级新组合 ;黄蓉花 ( Dalechampia bidentata)分布至云南西南部 ,D. bidentata var. yunnanensis为其新异名 ;海人树 ( Suriana maritima) ,广东省的东沙群岛才有 ,台湾不产 ;锥序丁公藤 ( Erycibe subspicata)其分布东缘在贵州西南部 ;头花小牵牛 ( Jacquemontia tamnifolia) ,广东的归化杂草 ;松下草 ( Petrosavissinii) ,广东新记录     

金钟藤的危害与利用

金钟藤是旋花科。打花碗属的一种大型缠绕藤本或亚灌木植物。在森林中。它缠绕幼树使其扭曲变形,影响其正常生长;遮蔽成树接受阳光照射,无法进行光合作用,最终导致其死亡。通过介绍金钟藤的生长特点、分布和危害情况。探讨其防治方法及其可利用的可能性和价值。     

金钟藤研究述评

述评了近年来有关金钟藤的报道和研究成果,论证确认金钟藤是喜光的阳性藤本植物,而不是阴性植物,具有广幅生态适应性,并含有入侵物种入侵机制之一的化感物质.金钟藤在中国分布于云、桂、粤,福建的分布则没有确证.广州及其附近正在成为该种新的分布区域,尽管倾向是由于全球变暖而导致从海南北移入侵的结果,但金钟藤毕竟不是纯热带植物,而是热带亚热带成分,北回归线是其分布的北界,因而极可能是全球变暖而激活的潜在本地物种.金钟藤在越南这个模式标本产地和海南这个原分布中心的蔓延成灾,有别于入侵物种在原产地因有天敌而不能蔓延成灾的论点,或显示其在原产地尚无致命的天敌.金钟藤能够蔓延成灾的根源在于干扰破坏了原有的自然生态系统,导致生境恶化、破碎、异质化、群落生物多样性和物种功能组群多样性的贫乏,增强了群落的可入侵性,从而给予入侵物种入侵的机遇,因而金钟藤入侵无选择性的论点值得商榷.金钟藤危害的防治仍待突破,利用综合防治策略应是首选,而防止干扰破坏自然生态系统、改建、重建和优化被干扰破坏的生态系统应是必要的策略和措施.

Abstract：

Recent researches demonstrated that Merremia boisiana is a photophilous heliophyte liana rather than a sciophyte, which has a wide ecological adaptability and contains the allelo-chemicals, one of invasion mechanisms of invasive species. In China, M. boisiana had a distri-bution in Yunnan, Guangxi, and Guangdong Provinces, but its distribution in Fujian Province has not been confirmed. Guangzhou City and its vicinity are becoming a new distribution area of M. boisiana due to its northward invasion from Hainan under global warming. However, M. boi-siana is not really a kind of tropical plants, but one of the tropical and subtropical elements. The tropic of cancer is the north boundary of M. boisiana distribution, and thereby, there is a high possibility that M. boisiana is a latent local species activated by global warming. M. boisiana causes widespread disaster in its holotype locality (Vietnam) and its original distribution center (Hainan Province), which is not consistent with the existing viewpoint that the invasive species cannot spread to be a disaster owing to the natural enemies in origin, while suggests that there are no fatal natural enemies in the origin. The widely spreading to be a disaster is originated from the intrinsic ecosystem being destroyed by disturbances, which causes the worsened, broken, and heterogeneous habitat. The reduced community biodiversity and functional group diversity intensi-fy the invasive possibility of exotic communities and provide chance for invasive species. There-fore, the viewpoint that the invasion of M. boisiana is non-selective should be modified, and the prevention measures of M. boisiana remain to be break through. Integrative control should be the first choice. Additionally, protecting the natural ecosystem from disturbance, and reconstructing and optimizing the destroyed ecosystem would be the necessary strategies and measures.     

值得注意的中国南部植物

通过整理和研究华南植物园标本馆(IBSC)、中山大学植物标本馆(SYS)等馆藏标本,发现我国南部生长的而在《中国植物志》或“Flora of China”有未收载的物种及需处理1个新组合和2个新异名外,还有省级新记录等情况。现补充增加3个归化种白花假马鞭、毛苘麻和大花假番薯;广西2个新记录夜牵牛和红岩野桐(新组合);广东1个新记录粘毛苘麻,并处理本种的1个新异名;粗糠柴为西藏新记录。此外,处理隶于东南野桐的1个新异名;补充隶于草牵牛的1个异属名。     

值得注意的中国植物

近年为研究中国的大戟科、檀香科等科的植物,对中山大学生物系植物标本馆（ＳＹＳ）、华南植物研究所标本馆（ＩＢＳＣ）等的标本予以重新鉴定．现将中国植物区系中一些属或种作必要的修订,增加《中国植物志》未收载的２个新记录种,处理１个新异名．