摘要
采用空间代替时间的方法研究了浙江古田山植物群落演替过程中石栎种子的形态变异模式,并通过冗余分析法(redundancy analysis,RDA)分析了种子形态特征与生态因子间的关系。结果表明:群落演替阶段是影响种子形态变异最重要的生态因子(P<0.001),海拔的影响次之(P<0.001),坡度的影响微弱(P>0.05)。随着群落演替发展,石栎种子的长度、直径和体积的变异幅度均显著增加(P<0.001);Ⅱ级种子的比例随演替发展逐步下降,Ⅰ、Ⅲ级种子相应逐步增加,种子大小分配由前期的相对均匀转向后期的两极分化。种子空壳率随演替发展逐步上升,演替中期显著高于前期(P<0.001),演替后期又显著高于中期(P<0.001)。推测群落演替引发的群落结构和光环境的复杂化可能是种子形态变异的重要诱因。进一步分析发现,群落演替后期的种子形态特征足以降低石栎种群的更新能力,这可能是石栎在演替后期群落中出现更新受限现象的重要原因。
By substituting spatial difference for temporal change, this paper studied the morphological variation patterns of Lithocarpus glaber seeds in evergreen broadleaved forest during the succession of plant communities in Gutian Mountain of Zhejiang Province, and the redundancy analysis （RDA） was adopted to analyze the relationships between the seed morphological characteristics and ecological factors. The results indicated that succession stage explained the majority of the variation of the seed morphology （P〈0.001）, elevation was ranked as the second （P〈0.001）, while slope had minor effects on the variation. With the succession of the plant communities, the coefficients of variation of the L. glaber seed length, seed diameter, and seed volume all increased significantly （P〈0.001）. Furthermore, the proportion of the second grade seeds declined with succession, while the proportions of the first grade seeds and third grade seeds increased steadily, resulting in the polarization of seed size at the late succession stage. The proportion of empty seeds increased gradually with succession, leading to the significantly higher empty seed percentage at middle succession stage than at early succession stage （P〈0.001）, and also, at late succession stage than at middle succession stage （P〈0.001）. It was speculated that the morphological variation of L. glaber seeds could be attributed to the changes in the light environment and community structure during the process of succession. Further analysis revealed that the seed morphological characters of L. glaber at the late succession stage of plant communities could lead to the severe regeneration barrier for L. glaber, which might explain the observed regeneration failure of this species.
出处
《生态学杂志》
CAS
CSCD
北大核心
2012年第10期2449-2454,共6页
Chinese Journal of Ecology
基金
国家自然科学基金项目(30970430)资助
关键词
种子
群落演替
形态变异
石栎
古田山
seed community succession morphological variation Lithocarpus glaber Gutian Mountain.
