百山祖常绿阔叶林种子雨组成及特点

Composition and Characteristics of Seed Rain in Baishanzu Broad-Leaved Evergreen Forest

为了解百山祖常绿阔叶林种子雨组成及其在时间上的动态变化，以百山祖自然保护区5hm^2永久样地为研究对象，设置50个种子雨收集器，定期收集2009—2012年间木本植物凋落物中的繁殖器官，鉴定到种并计数。四年间共收集到47个物种的果实或种子，隶属于16科30属，其中种子10132粒，果实13627个，成熟果实占41．33％。6个群落优势物种的成熟果实量占该物种总结实量的比例较低，显示出r-选择者的特点。优势种在样地内的重要值与其种子雨密度并不存在明显的相关性（P〉0．05），体现了种子雨和后续生活史阶段格局的不一致。优势种的种子雨凋落高峰时间相对分散，有利于缓解种间竞争。除木荷和多脉青冈外，其余优势种种子雨密度均存在明显的年际变化。

We established 50 seed rain traps in a 5 hm2 forest plot in Baishanzu National Natural Reserve to study the composition and temporal dynamics of seed rain in community of Baishanzu broad-leaved evergreen forest. We collected seeds and fruits twice a month during 2009 -2012, then identified and divided into four types, including mature fruit, immature fruit, young fruit and seed, and counted by types. During the four-year research period, we collected 13 627 fruits and 10 132 seeds, including 5 632 mature fruits accounting for 41.33%, belonging to 47 species, 30 genuses and 16 families. Six dominant species＇ mature fruits took a comparatively low rate in total fruit number of that species, showing the feature of r-stratagem in Grime＇s theory. There was no significant correlation （ P 〉 0.05 ） between the important value of the dominant species in the plot and their seed density, indicating the different conditions between seed rain and life history pattern afterwards. The asynehrony in seed rain dispersal peak time can relieve inter-specific competition and increase species co- existence. The seed rain density of dominant species, except Schima superba and Cyclobalanopsis multinervis, showed obvious interannual variability.