植物生态学报 ›› 2007, Vol. 31 ›› Issue (4): 637-644.doi: 10.17521/cjpe.2007.0082

• 论文 • 上一篇    下一篇

卧龙亚高山暗针叶林不同林冠环境下华西箭竹的克隆生长

宋利霞; 陶建平*; 冉春燕; 余小红; 王永健; 李媛   

  1. 西南大学生命科学学院, 三峡库区生态环境教育部重点实验室, 重庆 400715
  • 出版日期:2007-07-30 发布日期:2007-07-30
  • 通讯作者: 陶建平

CLONAL GROWTH OF FARGESIA NITIDA UNDER DIFFERENT CANOPY CONDITIONS IN A SUBALPINE DARK CONIFEROUS FOREST IN WOLONG NATURE RESERVE, CHINA

SONG Li-Xia; TAO Jian-Ping*; RAN Chun-Yan; YU Xiao-Hong; WANG Yong-Jian; LI Yuan   

  1. Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, College of Life Sciences, Southwest University, Chongqing 400715, China
  • Online:2007-07-30 Published:2007-07-30
  • Contact: TAO Jian-Ping

摘要:

该文调查了林下、中林窗、大林窗和林缘旷地等4种亚高山暗针叶林林冠环境下的华西箭竹(Fargesia nitida)分株种群,对其当年生立竹和母株的特征进行了比较研究,并探讨了母株年龄及大小对克隆生长的影响。主要研究结果如下:1)华西箭竹当年生立竹的分株密度以林下种群的最低,从林下→中林窗→大林窗,随林冠郁闭度的减小,华西箭竹基株当年生立竹的分株数逐渐增大。2)4种林冠环境下,当年生立竹和母株的分株高度、基径和生物量均有显著差异,且随林冠郁闭度的减小有递增的趋势(林下<中林窗<大林窗)。 3)各林冠环境均以二龄母株产生的当年生立竹数量最大,不同林冠环境之间母株的平均年龄,以及处于同一林冠环境的各龄级母株产生的当年生立竹平均分株数和平均基径均无显著差异。4)不同林冠环境下,华西箭竹当年生立竹基径与一级母株、二级母株基径均呈正相关关系,但当年生立竹基径随一级母株增加的速度快于随二级母株的增加。5)当年生立竹的基径与地下茎直径呈显著的正相关;母株的基径与当年生立竹的地下茎直径呈正相关关系,而与其地下茎长度相关性不明显。

Abstract:
Aims Fargesia nitida, one of the Giant Panda’s main food sources, is adapted to varied canopy conditions through changes in morphology and/or biomass allocation. We hypothesized that changes in clonal regeneration may be another way for this plant to be adapted to different canopy conditions.
Methods From August to September 2005, we measured the number, size and rhizome size of new shoots and the age and size of the parent ramet in four canopy conditions: forest understory (FU), moderate gap (MG), large gap (LG) and forest edge wilderness (FEW) in an Abies faxoniana forest in Wolong Nature Reserve in the western Sichuan, China. The data were analyzed by One-Way ANOVA, independent-sample t-test and regression.
Important findings The density of surviving new shoots was lower in the FU than that in the other three canopy conditions. With decreasing canopy cover (i.e., from FU to MG to LG), the number of surviving new shoots per genet increased. At the ramet level, the mean height, basal diameter, and biomass of surviving new shoots and parent ramet were significantly different (p<0.01) and increased as canopy cover decreased. In the different canopy conditions, the number of new shoots cloned by two-year-old primary parent ramets was the largest, but mean ages of parent ramets were not significantly different. There were no significant differences in average number and basal diameter of surviving new shoots reproduced by primary parent ramets with different ages in the same environment. In each canopy condition, the basal diameter of primary and secondary parent ramets were both positively correlated with basal diameter of surviving new shoots, but the effect of the primary parent ramets on surviving new shoots was stronger than that of the secondary parent ramets. The rhizome diameter of new shoots was positively correlated with the basal diameter of new shoots and primary parent ramet, but the rhizome
length of surviving new shoots was not significantly correlated with basal diameter of the primary parent ramet. These results indicated that the clonal growth features exhibited significant differences strongly correlated with canopy conditions.