栓皮栎橡子虫蛀特征与种子雨进程的关系

为了解栓皮栎(Quercus variabilis)种子雨过程及昆虫捕食特征,于2008年和2009年秋季在洛阳天池山次生林中,对栓皮栎种群的种子雨过程和象甲虫的寄生特征进行了调查研究。结果表明,2008年和2009年栓皮栎的种子雨分别发生在8月24日-9月24日、8月22日-9月28日,密度分别为(18.33±10.05)粒/m2、(26.42±14.27)粒/m2,2009年种子雨产量显著大于2008年。2a的种子雨构成比例有较大差异。2008年,完好种子、败育种子和虫蛀种子的比例分别为24.09%、55.90%和20.01%;2009年,完好种子比例为50.16%,显著高于2008年,败育种子比例为30.28%,显著低于2008年,而虫蛀种子比例为19.56%,2a间无显著性差异。象甲幼虫寄生率与橡子大小呈显著正相关,说明象甲虫喜欢寄生较大的橡子。

Relationship between Insect Infestation and Seed Rain Dynamics of Oriental Cork Oak(Quercus variabilis)

The seed rain dynamics of Quercus variabilis and the characteristics of weevil infestation were investigated in 2008 and 2009 in Luoyang Tianchi mountain forests.Our results showed that the seed rain of Quercus variabilis began from 24 August and ceased on 24 September,with seed density of(18.33±10.05) acorn/m2 in 2008.In 2009,the seed rain began from 22 August and ceased on 28 September,with seed density of(26.42±14.27) acorn/m2,significantly larger than that in 2008.In addition,large difference was also found in the composition of seed rain in the two years.In 2008,the proportions of sound acorns,aborted acorns and insect-infested acorns were 24.09%,55.90% and 20.01%,respectively.In 2009,however,the corresponding proportions were 50.16%,30.28% and 19.56%,respectively.The proportion of sound acorns in 2009 was significantly higher than that in 2008,while the proportion of aborted acorns in 2009 was significantly lower than that in 2009,but no significant difference was found in the proportion of insect-infestedacorns between the two years.A significant positive relationship was found between infestation rate and acorn size,indicating that female weevils preferred larger acorns over smaller ones to oviposit.