长白山阔叶红松林乔木树种幼苗组成及其年际动态

Composition and interannual dynamics of tree seedlings in broad-leaved Korean pine(Pinus koraiensis) mixed forest in Changbai Mountain

为了解阔叶红松(Pinus koraiensis)林乔木树种幼苗的组成及其年际动态,以长白山阔叶红松林25ha动态监测样地为平台,在样地内150个种子收集器周围设置了600个5m×5m幼苗样方。基于2006-2008年连续3年的幼苗样方调查数据,对乔木幼苗的树种组成、数量组成、空间分布特征、年际动态、新增和死亡幼苗组成等进行了分析。结果表明:(1)从树种组成来看,该群落乔木树种的幼苗组成种类较为丰富,共记录到21个树种,这些树种也是样地内胸径1cm以上乔木树种的主要组成成分。树种组成在年际间变化不大,但各样方间表现出极大的空间变异。(2)从数量组成来看,共记录到11,959株乔木幼苗,以水曲柳(Fraxinus mandshurica)和紫椴(Tilia amurensis)幼苗数最多,占总幼苗数的72.75%;水曲柳、紫椴和红松的幼苗数量在年际间有明显波动,其他树种年际间波动较小。(3)从新增和死亡幼苗的数量与组成来看,共记录到15个乔木树种的新增幼苗,其中紫椴、水曲柳、色木槭(Acer mono)、红松等10个树种在每次调查中都有新苗记录,新苗数量在年际间随物种和样方位置表现出明显差异。(4)对各树种的幼苗、种子和大树的组成和空间分布的比较发现,各树种的幼苗、种子和大树之间的数量组成和比例差异较大,其中紫椴、水曲柳、色木槭和假色槭(A.pseudo-sieboldianum)的幼苗、种子在整个样地内都有分布,春榆(Ulmus japonica)和怀槐(Maackia amurensis)幼苗的空间分布与种子和大树不一致,糠椴(T.mandshurica)和山丁子(Malus baccata)等的幼苗、种子和大树的个体数相对都较少,且它们的分布是一致的。

To explore the composition and interannual dynamics of tree seedlings in a broad-leaved Korean pine mixed forest, 600 25 m2 （5 m×5 m） seedling quadrats were set up in a 25-ha plot of the forest in Changbai Mountain. All seedlings in these quadrats were tagged, measured and identified to species. Based on three seedling censuses between 2006 and 2008, we analyzed species composition, spatial distribution, and interannual dynamics of tree seedlings. A total of 21 tree species were recorded in these quadrats, which was consistent with the composition of trees with 〉1 cm diameter at breast height. There was no significant interannual difference on species composition, but great variations among different seedling subplots. There were 11,959 tree seedlings recorded in three censuses, of which Fraxinus mandshurica and Tilia amurensis comprised of 72.75%. The seedling numbers ofF. mandshurica, T. amurensis, and Pinus koraiensis varied greatly among three censuses, while the numbers of other species varied little. Recruit seedlings of 15 species were recorded in three censuses, of which 10 species （T. amurensis, F. mandshurica, P koraiensis and so on） were found every year. The numbers of recruit seedlings showed great interannual variations among different species and quadrats. Compared spatial distribution of tree seedlings with their seeds and large trees, we found that there were significant differences on individual numbers among different species. For T. amurensis, F. mandshurica, Acer mono, and A. pseudo-sieboldianum, their seeds and seedlings could be found in the entire 25-ha plot. For Ulmus japonica and Maackia amurensis, the distributions of their seedlings were inconsistent with their seeds and large trees. For T. mandshurica and Malus baccata, with fewer seeds, seedlings, and large trees, the distributions of seedlings were consistent with these of their seeds and large trees.