金佛山不同群落紫耳箭竹生长和繁殖权衡的形态及生物量特征

目的 探究紫耳箭竹种群(Fargesia decurvata J. L. Lu)在不同林型下的生长和繁殖特征，探讨长寿命一次性开花结实的竹类克隆繁殖和有性繁殖的权衡特性。 方法 以金佛山国家级自然保护区3个典型林型：落叶阔叶林(De)、常绿落叶阔叶混交林(De+Ev)和常绿阔叶林(Ev)下的灌木层优势种紫耳箭竹为试验材料，研究不同林型下紫耳箭竹种群在营养生长期和果期的形态可塑性、生物量积累与分配特性以及繁殖特征。 结果 表明：(1)相较于营养生长期，果期紫耳箭竹单株叶片数在De和De+Ev中显著减少，在Ev中没有显著变化；隔离者长度、隔离者节间数、隔离者直径、隔离者节间均长在De和De+Ev中均降低，在Ev中均增加；果期De中的紫耳箭竹单株小穗数高于De+Ev和Ev。(2)从营养生长期向果期过渡过程中，De和De+Ev中的紫耳箭竹分株叶片生物量和分配比例急剧下降，其余构件的生物量和分配比例无明显变化；Ev中各构件生物量除叶片外均显著增加，分配比例则在枝中显著增加，在叶片和根中显著降低；秆和枝作为支撑器官在3个林型中均占据很大的生物量分配。(3)在营养生长期，3个林型中的紫耳箭竹均产生竹笋进行克隆生长，且De+Ev中的竹笋数显著高于Ev，Ev的单位面积竹苗数显著低于其余2种林型，秆组织密度显著低于果期。在果期均不产生竹笋只产生种子，且单株结实率和生殖分配都很低。 结论 紫耳箭竹种群的形态特征、生物量积累与分配特性在不同生活史阶段不同，且在不同林型间也存在差异；克隆生长与有性繁殖间存在明显的权衡，随着有性繁殖的进行，克隆生长能力随之变弱并逐渐消失。

Morphological and Biomass Characteristics of Fargesia decurvata in Different Forest Types in Jinfo Mountain

Objective To study the growth and reproduction characteristics of Fargesia decurvata J. L. Lu under different forest types, and the trade-off characteristics of clonal reproduction and sexual reproduction of long-lived, one-time flowering bamboos. Method F. decurvata, the dominant species in shrub layer under three forest types, i.e. deciduous broad-leaved forest (De), evergreen deciduous broad-leaved mixed forest (De+Ev) and evergreen broad-leaved forest (Ev) was selected as experimental materials, to study the morphological plasticity, biomass accumulation and biomass distribution characteristics and reproductive characteristics in vegetative stage and ripening stage. Result (1) From vegetative stage to ripening stage, the amount of leaves decreased significantly in De and De+Ev, and there was no significant change in Ev. The length of the splitter, the amount of internode of the splitter, the mean diameter of the splitter, and the internode length of the splitter all decreased in De and De+Ev, and increased in Ev. During the ripening stage, the amount of spikelets in De was higher than that in De+Ev and Ev. (2) During the transition from vegetative growth to ripening stage, the leaf biomass accumulation and leaf biomass allocation of F. decurvata ramets in De and De+Ev decreased sharply, there was no significant change in the biomass of other components in this two types of forest; the biomass accumulation of each component in Ev increased significantly except for the leaves, and the biomass allocation increased significantly in the branches, and decreased in the leaves and roots; the stems and branches as supporting organs accounted for a large amount of biomass allocation in the three forest types. (3) During the vegetative growth stage, F. decurvata in the three forest types produced shoots for clonal growth, and the amount of bamboo shoots per unit area of De+Ev was significantly higher than Ev. However, no shoots were produced during the ripening stage, only seeds were produced, and the amount of bamboo seedlings per unit area of Ev was significantly lower than that of the other two forest types. The tissue density was significantly higher than that in vegetative growth stage. The seed setting rate and reproductive distribution of F. decurvata were very low. Conclusion The morphological characteristics, biomass accumulation and biomass allocation characteristics of F. decurvata population are different in various life history stages, and there are also differences among these forest types. There is an obvious trade-off between clonal growth and sexual reproduction, as sexual reproduction progresses, the clonal growth capacity will weaken and disappear.