蒙古栎种子相对丰富度对小兴安岭5种木本植物种子扩散的影响

Effects of relative abundance of Quercus mongolica acorns on five tree species seed dispersal in Xiaoxing’an Mountains, Northeast China

2009和2010年秋季,在黑龙江省伊春市带岭区东方红林场研究了蒙古栎结实量及啮齿动物密度变化对胡桃楸、红松、蒙古栎、毛榛和平榛5种木本植物种子扩散的影响.结果表明:在小兴安岭林区,啮齿动物种群数量具有年际变化,2009年小型啮齿动物的总捕获率(31.0%)显著高于2010年(16.7%);2009年蒙古栎种子雨密度(6.2±2.1粒·m-2)和种子相对丰富度(20.0)均显著低于2010年(26.7±10.2粒·m-2和160.0).2009年,除胡桃楸种子外,其他种子全部被扩散或者被原地取食,其中蒙古栎种子被分散埋藏的比例最高,且种子平均扩散距离最大;2010年,胡桃楸种子被分散埋藏的比例最高,且种子平均扩散距离最大.研究区蒙古栎种子相对丰富度是影响其他木本植物种子扩散的重要因素.

An investigation was conducted in a forest farm in the Xiaoxing’an Mountains in autumn, 2009 and 2010 to study the effects of Quercus mongolica acorn quantity and rodent density on the seed dispersal of five tree species （Juglans mandshurica, Pinus koraiensis, Corylus mandshurica, Corylus heterophylla, and Q. mongolica）. In the farm, there was an annual change in rodent density. The total capture rate of small rodents in 2009 （31.0%） was significantly higher than that in 2010 （16.7%）. The acorn quantity and relative seed abundance （per capita rodent） of Quercus mongolica in 2009 （6.2±2.1 acorns·m-2 and 20.0, respectively） were significantly lower than those in 2010 （26.7±10.2 acorns·m-2 and 160.0, respectively）. In 2009, all the seeds of the five tree species except J. mandshurica were dispersed or eaten in situ, among which, the acorns of Q. mongolica were scatter-hoarded most, and their average dispersal distance was the furthest. In 2010, the seeds of J. mandshurica were scatter-hoarded most, and their average dispersal distance was the furthest. The relative seed abundance of Q. mongolica could be the key factor determining the seed dispersal of the other tree species in the study area.