鼎湖山锥栗种子扩散过程中死亡因素分析

Analysis of seed death of Castanopsis chinensis in the dispersal process in Dinghushan biosphere reserve

研究了锥栗(Castanopsischinensis)种子扩散过程中死亡的主要因素。实验分为无处理组、鸟类取食组、排除鸟类取食组、排除哺乳动物组和种子袋法。结果表明,扩散前种子主要受栗实象甲(Curculiodavidi)取食和病原体感染,其取食率在鼎湖山3种林型之间显示了较大差异。排除实验的研究表明,锥栗种子在扩散后承受啮齿类、鸟类等动物取食和病原体感染致死的巨大压力,其中无覆盖处理实验组的种子取食平均比例高达93.3%,鸟类对种子取食率约为80%,排除鸟类实验组中的种子平均取食率为92.4%,非哺乳动物对种子的取食在3个林型有差异,但不是显著性的。因此,巨大的种子死亡或丧失是锥栗自然更新率非常低的主要原因。

Major factors caused seed death of Castanopsis chinensis in the dispersal process were studied. The experiments included Open treatment group, Predation by birds experiments, Exclusion birds group, Exclusion small mammals experiments, and seed bag methods. The results showed that seeds were mainly predated by Curculio davidi and infected by pathogens, and the ratio of predation among three forest types had an obvious difference. The exclusion experiments suggested that seeds endured great pressure after dispersal by animal predation and pathogen infection. In Open treatment group （OP） experiment, ratio of seed predation was up to 93.3%, while it was 92.4% in the Exclusion birds group （EB）, but the seed predation rate by birds was only 80%. There was a difference between seed predation by non-mammals of three forest types, but it was not significant. So great seed death rate is the major reason caused Castanopsis chinensis recruitment limitation.