优势种是植物群落各层次中占优势的植物种,混交林优势树种竞争关系的研究对合理经营混交林具有重要意义.本研究在吉林省汪清县金沟岭林场内,选择立地条件一致的云冷杉天然林,设置大小100 m×100 m样地.首先,用优势度分析法确定群落优势树种;其次,以优势树种为对象木,采用可描述单株林木侧方上方、种内种间竞争强度的林木竞争指数分析优势树种的竞争关系.结果表明:该云冷杉天然林有3个优势树种:臭冷杉、红皮云杉、红松.样地中,小径级林木较多,群落林木趋于小龄化,3个优势树种的竞争树种主要有臭冷杉、红皮云杉、红松、枫桦、紫椴、青楷槭和白桦.3个优势树种受到的竞争最激烈的是臭冷杉(1412.48),其次是红皮云杉(439.17)、红松(245.28),都主要承受侧方挤占,臭冷杉、红皮云杉、红松的侧方挤占分别占各优势树种竞争强度的64.9%、65.2%、66.0%;3个优势树种侧方上方平均竞争强度大致随个体胸径的增大而减少,小径级林木的侧方上方平均竞争强度几乎相等,对象木径级越大,所承受的侧方挤占比例越大,大径级林木几乎不承受上方遮盖;3个优势树种的侧方上方竞争主要来源于臭冷杉、红皮云杉、红松、紫椴、枫桦、青楷槭和白桦.3个优势树种种间竞争均比种内竞争激烈,臭冷杉、红皮云杉、红松的种间竞争分别占各优势树种竞争强度的58.4%、87.1%、83.7%,且竞争强度大致随个体胸径的增大而减少. The dominant species is the dominant plant species at all levels of the plant community, and the study on the competitive relationship between the dominant tree species in mixed forest is of great importance to the rational management of the mixed forest.In this study, in the Jingouling Forest Farm of Wangqing County, Jilin Province, Fir natural forest, the size of plots of 100 m × 100 m was set up.First, dominance tree species were determined by dominance analysis method; Secondly, the dominant tree species was taken as wood, The results showed that there were three dominant tree species in the native forest of Fir (Abies smithii): Fiery fir, spruce (Picea koraiensis) and Korean pine In the younger age, the dominant species of the three dominant species were A. fir, P. spruce, P. korshinskii, Betula platyphylla, Tilia amurensis, A. japonica and Betula platyphylla. The three most dominant species were the most competitive species, (1412.48), followed by the red spruce (439.17), Korean pine (245.28), are mainly occupied by the side of the crowd, stinky fir, red spruce, red pine side occupy the dominant species accounted for the competitive intensity of 64.9 %, 65.2%, 66.0%; three advantages The average competitive intensity above the lateral sides of the species decreased with the increase of the DBH of the individuals. The average competitive intensity of the lateral tops of the DBHs was almost the same. The greater the diameter of the woods, the greater the proportion of lateral crowding, The trees were almost not covered by the top cover. The top-side competition among the three dominant species mainly came from the competition among three dominant tree species, namely, Fiery FIR, Picea koraiensis, Korean pine, Tilia amurensis, Betula platyphylla, The competition among the species was fierce. The interspecific competitions of F. obliquus, P. koraiensis and P. koraiensis accounted for 58.4%, 87.1% and 83.7% of the competition intensity of dominant species respectively, and the competition intensity decreased with the increase of DBH.