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作 者 ：刘仲健*,陈利君,刘可为,李利强,张玉婷,黄来强

期 刊 ：生态学报 2009年 29卷 7期 页码：3443~3455

关键词：墨兰；种群动态；Leslie模型；Levins模型；气候变暖；水分胁迫；濒危机制；

Keywords:Cymbidium sinense, population dynamics, Leslie matrix model, Levins model, climate warming, water stress, endangering mechanism,

摘 要 ：温室效应和气候变化通过影响植物生长发育和水分循环过程，对植物的生存产生重大影响，特别是与环境高度适应的兰科植物。通过对深圳野生墨兰（Cymbidium sinense）的生物学特征调查和生殖行为观察，计算出其各龄级的存活数、出现频率和子代数以及空间分布格局，编制种群静态生命表和生殖力表、绘制存活曲线和年龄锥体，构建Leslie矩阵模型、Levins模型和连续下降模型Nt=Nt-1-Nt-1e-2.329对种群数量动态过程进行预测，结合气象数据分析，以检验墨兰种群对气候变化的响应。结果表明：在气温上升引发相对湿度降低和降雨失衡形成干旱的环境条件下，墨兰表现出的空间结构为成群分布，种群的年龄锥体属于壶型锥体，种群存活表现近似于DeeveyⅠ型，种群的净增长率、内禀增长率和周限增长率很低，墨兰种群正处于下降态势。究其原因是，墨兰在生理上表现出对干旱的敏感和高温使光合速率下降，影响营养物质积累以及高温直接抑制花芽分化或造成花芽败育，从而影响了有性繁殖，减少了后代的生产。尽管其有性繁殖是通过花香和花外蜜吸引中华蜜蜂（Apis cerana）传粉，产生含有大量种子的果实。但只有少量种子可以在野外环境中萌发，而萌发出的幼苗大多数因干旱不能成长到有性繁殖阶段。墨兰的种群数量动态随气候的波动而波动的结果证明了气候暖化和降雨失衡引起的干旱影响着墨兰的生殖和生长过程，成为其种群发展的致死因子。这种作用的持续或进一步加剧将使墨兰在该地区消失，因此，有必要对该物种进行迁地保护或种质资源人工保存。墨兰对气候变化的响应应引起人们对全球暖化给植物生存所带来的威胁的关注。

Abstract:Greenhouse effects and climate changes have great influence on the survival of plants by affecting the development and the process of water cycling in plant, especially on Orchidaceae plants with high adaptation to the environment. Based on the investigation of biological characteristics and the observation of reproductive behavior among the wild populations of Cymbidium sinense in Shenzhen City, we calculated the quantity of survival plants, the frequency of appearance, the quantity of filial generation and the spatial distribution pattern at different age class, made static life graph and reproductivity graph of the population, drew the survival curve and age pyramid, and made up the Leslie matrix model, Levins model and consecutive decline model, Nt=Nt-1-Nt-1e-2.329, to predict the dynamic procedure of population quantityand test how C. sinense population responded to the climate changes combined with the analysis of meteorological data. The test result showed that, in conditions of low relative humidity arose from temperature rise and drought caused by rainfall imbalance, C. sinense showed a spatial structure of group distribution, and its age pyramid was kettle\|shaped and the survival performance of population was similar to DeeveyⅠtype. The net reproduction rate, the intrinsic increase rate and finite increase rate of C. sinense were very low, indicating that the population was in a situation of downward tendency. And the reason is that, C. sinens is physiologically sensitive to drought condition and high temperature decreases its photosynthetic rate, which affects the accumulation of nutrients and directly restrains the differentiation of flower buds or even causes the abortion of flower buds, accordingly the sexual reproduction is influenced and the progeny production is reduced. Even though the sexual reproduction of C. sinense was achieved by attracting the honeybee, Apis cerana, to pollinate flowers by fragrance and extrafloral nectar and produced fruits with mass seeds, only a few seeds could germinate in wild and most of the germinated seedlings could not grow through the sexual reproductive stage due to drought. The dynamic of population quantity of C. sinense fluctuates along with the climate, which consequently confirmed that drought caused by climate warming and rainfall imbalance affected the reproduction and growing process of C. sinense, and became the lethal factor to the development of C. sinense population. If such influence continues or exacerbates, C. sinense would vanish from this region; therefore, it is necessary to carry out ex\|situ conservation or artificial reservation of germ plasm resource of this species. The response of Cymbidium sinense to the climate change should arouse people‘s concern about the threat to the survival of plant caused by global warming.

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