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森林是陆地生态系统重要的组成部分,具有涵养水源、净化空气、保育土壤、调节气候等重要的生态服务功能[1-3]。而森林更新是森林提供可持续生态服务功能的前提条件。关于森林更新的影响因素已经有很多研究,国外De Lombaerde等认为气候变化通过物理、化学和生物过程改变森林的能量分配、水文循环和大气成分等从而影响森林更新[4],国内闫兴富等在2011—2014年间研究了光照、温度、密度及动物取食行为对辽东栎幼苗更新的影响[5-8],方坚等分别研究了油松和辽东栎混交林的种间和种内竞争对群落和种群动态的影响[9],Berger (2004)等人观测了加拿大西部森林超过50年后报道,群落内部竞争产生的驱动力比外部气候因素更能推动森林产生动态变化[10]。但并列分析种群新生个体分别对胸径、密度、竞争等因素的响应的文章却较少。
种群更新对胸径、密度和竞争的响应通过新生个体与周围成树之间的相互作用体现,例如有文章研究发现成树对幼树的限制作用[11-13]。为了更加深入地了解种群内个体大小、密度和基于距离的竞争对幼苗更新的影响,本文以秦岭次生辽东栎种群为研究对象,以长期的连续观察代替时空互代法,设置了长达10年(观测频次为5年)的定位观测。采用插值法、密度函数法和基于距离的竞争指数法,对比分析了每5年新生个体对周围成树胸径大小、密度和竞争格局的响应,为秦岭次生辽东栎林的恢复和近自然管理提供参考。
Responses of Newborn Individuals to Population Spatial Pattern in Secondary Quercus liaotungensis Forest in the Qinling Mountains
doi: 10.12172/202007010002
- Received Date: 2020-07-01
- Available Online: 2020-09-01
- Publish Date: 2020-12-11
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Key words:
- Regeneration /
- DBH /
- Density /
- Competition /
- Quercus liaotungensis
Abstract: The secondary Quercus liaotungensis population in Qinling mountains was selected as the experimental object, and the population structure of Quercus liaotungensis and the responses of seedling regeneration to DBH pattern, density pattern and competition pattern were studied by using the relevant methods of spatial pattern analysis. The results showed that: (1) The number of small diameter individuals (DBH <16 cm ) was significantly higher than that of large diameter individuals (DBH ≥16 cm). (2) The average diameter at breast diameter (10.376 cm) around the seedling regeneration position was smaller than the average level of the plot (12.385 cm). (3) The population density of the seedling regeneration position (0.126 plants / m2) was higher than the average level of the plot (0.084 / m2). (4) The competition index of seedling regeneration position was at a moderate level of the plot, and the law was not obvious. The results provided some certain reference value for a deeper understanding of the secondary forest regeneration mechanism.