辽东山区天然次生林的数量分类

Classification and ordination of secondary forests in montane zone of eastern Liaoning Province

结合DCA排序和TW IN SPAN分类结果,将辽东山区天然次生林划分为5个群落类型:花曲柳林、蒙古栎林、阔叶混交林、水曲柳林、胡桃楸林。DCA排序与TW IN SPAN分类产生了较一致的分类结果。DCA第一轴代表的环境意义为坡向。花曲柳林多分布于阳坡的中坡及中上坡,蒙古栎林多分布在中上坡。花曲柳与蒙古栎常混生在一起,随着坡位上升,花曲柳优势度下降,而蒙古栎优势度增加。阔叶混交林多位于阴坡,乔木层没有稳定和绝对优势种,多以假色槭、风桦、色木槭为优势种,但假色槭分布于乔木层第2亚层。水曲柳林多分布在中下坡。胡桃楸分布在山下部,喜潮湿生境。色木槭在辽东山区分布广泛,重要值较高,且更新良好,很可能是群落演替顶级物种。辽东山区天然次生林林下藤本植株数量多,以五味子、软枣猕猴桃、狗枣猕猴桃为主。

We investigated 21 plots including 239 tree species, which were selected from the secondary forests in montane zone of eastern Liaoning province （41°51. 102′N,124°54. 543′E）. With the help of TWINSPAN classification and DCA ordination, the secondary forests were classified into 5 community types, including Fraxinus rhynchophylla community, Quercus mongolica community, Broadleaved stand community, F. madshurica community and Juglans mandshurica community. Then, the community characteristics of the 5 types were researched as well. Both DCA ordination and TWINSPAN classification exhibited the consistent results of secondary forest classifications. The first axis of DCA represented the slope aspects. The field survey indicated that F. rhynchophylla communities were often associated with Q. mongolica. They mainly distributed from hillside to hilltop, with decreasing of F. rhynchophylla dominance and increasing of Q. mongolica dominance. Broadleaved communities mostly distributed on the shade side, the arbor layer of this type of communities hadn＇t stable and absolute dominant tree species, but Acer pseudo-sieboldianum, Betula costata, A. mono often distributed as one of the dominant species. A. pseudo-sieboldianum mostly distributed at the second sub-layer of the arbor layer. F. madshurica communities mostly distributed from mesoslope to piedmont. J. mandshurica communities distributed on piedmont, and grew well in the wet habitats. With wide distribution and high dominance, Acer mono was an important species which had drawn our great attention because the species exhibited very good regeneration patterns in many kinds of stands. These indicated that the species of A. mono might be considered as the climax species in the study area. Another characteristic of the secondary forests in montane zone of eastern Liaoning Province might be the big biomass of liana, which were mostly accounted for by Schisandra chinensis, Actinidia arguta and A. kolomikta and so on.