关键词: 杉木人工林, 混交度, 物种多样性, 群落稳定性

Abstract: Mixing is an important way for nature-based afforestation. Understanding the effects of mingling degrees and species selection on community stability ofCunninghamia lanceolataplantations can provide scientific guidance for the sustainable afforestation. In this study, we analyzed the characteristics of community stability of C. lanceolataplantations under three mingling degrees (pure forest or low mingling degree with 0.051, moderate mingling degree with 0.297, high mingling degree with 0.598). The regeneration potential of dominant species, forest productivity, soil fertility, and species diversity were used for evaluating community stability with 12 different parameters. Results showed that the regeneration potential of dominant species increased by 32% in moderate mingling degree forests and by 100% in high mingling degree forests. Furthermore, there were more species of regeneration seedlings in mixed forests. The understory herbaceous biomass and species richness were higher in mixed forests than in pure forests, but the biomass of arbor species were 58% (in moderate mingling degree mixed forests) and 66% (in high mingling degree mixed forests) of pure forests, respectively. Soil fertility in pure forests was higher than that in mixed forests, which may be due to increasing demand of soil nutrients for higher species diversity and more seedlings. The membership function method in fuzzy mathematics was used to evaluate the community stability characteristics of C. lanceolataforests with different mingling degrees. Forests with moderate mingling degree had the highest community stability (0.909), followed by high mingling degree forests (0.882) and pure forests (0.856). Our results suggest that C. lanceolata, Sassafras tzumuand Quercus mixed forest with moderate mingling degree and reasonable planting density will sustain healthy succession and enhance ecosystem services.

Key words: Cunninghamia lanceolataplantation, mingling degree, species diversity, community stability.