地形和竞争对典型阔叶红松林不同生长阶段树木胸径生长的影响

近年来，地形和竞争对树木生长影响机制的研究备受关注。本文基于黑龙江凉水国家级自然保护区内9 hm2典型阔叶红松林动态监测样地，使用2010年和2015年的野外调查数据，分析了地形(坡向、坡度、坡位)和树木间竞争对阔叶红松林主要组成树种胸径生长的影响。结果表明:紫椴、色木槭、冷杉径级Ⅰ(1 cm≤DBH＜10 cm)以及红松、紫椴、色木槭、水曲柳径级Ⅱ(DBH≥10 cm)的胸径年均生长量与地形显著相关(P＜0.05)；竞争对红松、紫椴、色木槭、水曲柳、冷杉、枫桦、青楷槭径级Ⅰ以及红松、紫椴、色木槭、冷杉、春榆径级Ⅱ的胸径年均生长量有显著影响(P＜0.05)。总体上，阔叶红松林中耐荫和非耐荫树种组的胸径年均生长量均受地形和竞争的显著影响；阔叶红松林中大径级树木的胸径生长主要受地形影响，而小径级树木的胸径生长主要受竞争影响。 

Influences of topography and competition on DBH growth in different growth stages in a typical mixed broadleaved-Korean pine forest,northeastern China

In recent years, the influencing mechanism of topography and competition on tree growth is getting more attentions. The research was conducted in a 9 ha dynamic monitoring plot of typical mixed broadleaved-Korean pine ( Pinus koraiensis) forest in Liangshui Natural Reserve, Heilongjiang Province of northeastern China. Based on field investigation data in 2010 and 2015, this study analyzes the influences of topography ( i. e. , slope aspect, slope gradient, slope position ) and competition among trees on the increment of diameter at breast height ( DBH) for major tree species in mixed broadleaved-Korean pine forest. Results showed that the annual average DBH increment of diameter classⅠ(1 cm≤DBH<10 cm) for Tilia amurensis, Acer mono and Abies nephrolepis as well as diameter classII( DBH≥10 cm) for Pinus koraiensis, Tilia amurensis, Acer mono, Fraxinus mandshurica were all significantly correlated with topography ( P<0. 05 ) . The competition had significant influences on the annual average DBH increment of Pinus koraiensis, Tilia amurensis, Acer mono, Fraxinus mandshurica, Abies nephrolepis, Betula costata, Acer tegmentosum for diameter classⅠas well as diameter classIIfor Pinus koraiensis, Tilia amurensis, Acer mono, Abies nephrolepis, Ulmus japonica ( P<0. 05 ) . Generally, the annual average DBH increment of shade-tolerant and non shade-tolerant groups was significantly influenced by both topography and competition in mixed broadleaved-Korean pine forest. The DBH increment of large diameter classes of trees was mainly influenced by the topography, while the DBH increment of small diameter classes of trees was mainly influenced by the competition.