陕西米仓山自然保护区6种典型天然林群落的物种多样性

Species diversity of six typical natural forest communities in Shaanxi Micangshan Nature Reserve

【目的】研究陕西米仓山自然保护区内6种典型天然林群落的物种多样性及其影响因子,为进一步了解保护区内物种的生长发育和揭示典型群落的更新演替规律提供理论依据。【方法】采用典型取样的方法,分别从6种典型天然林群落(包括铁杉群落、马尾松群落、胡桃楸群落、大叶榉群落、油松群落和栓皮栎群落)不同层次的丰富度、均匀度、物种多样性指数和优势度指数等方面,对陕西米仓山自然保护区典型天然林群落的物种多样性进行分析。【结果】马尾松群落与油松群落乔木层、灌木层和草本层的物种数分别为14,32,16种与17,50,51种;大叶榉群落、铁杉群落与栓皮栎群落乔木层、灌木层和草本层的物种数分别为11,12,12种,7,15,11种与4,15,14种;胡桃楸群落乔木层、灌木层和草本层的物种数分别为1,4,14种。6种典型天然林群落在乔木层、灌木层和草本层的物种多样性差异较明显,灌木层和草本层的多样性指数大于乔木层,不同群落间物种相似性指数普遍偏低。其中油松群落各层次的物种最为丰富,各层次平均优势度指数也大于其他5种群落;胡桃楸群落各层次优势种地位突出,铁杉群落和栓皮栎群落乔木层的优势种显著,油松群落和马尾松群落各个层次的物种多样性丰富;此外,马尾松群落、胡桃楸群落和栓皮栎群落灌木层中建群种幼苗、幼树数量丰富。【结论】铁杉天然林群落已经处于演替的顶级阶段,群落相当稳定;油松群落和马尾松群落物种丰富,群落相对复杂,森林结构比较稳定;马尾松群落、胡桃楸群落和栓皮栎群落自然更新的潜力较大,应加强对这些天然林群落的保护。

[Objective] Species diversity and impact factors of 6 typical natural forest communities inShaanxi Micangshan Nature Reserve were studied to further understand the growth and development of species in protected areas and reveal the regeneration of typical communities. [Method] Through the typi- cal sampling method, this study investigated species diversity of 6 typical natural forest communities （ Tsuga chinensis community, Pinus massoniana community, Juglans mandshurica community, Zelkova schneideriana community , Pinus tabuli f ormis community, and Quercus variabilis community） from rich- ness,evenness,species diversity index and dominance index. [Result] The numbers of species in P. masso-niana community and P. tabuliformis community in tree layer, shrub layer and herb layer were 14, lb and 17,50,51 respectively. The numbers in Z. schneideriana community, T. chinensis community and Q. variabilis community in tree layer, shrub layer and herb layer were 11,12,12 - 7,15,11 and 4,15,14, re- spectively. The numbers in J. mandshurica community in tree layer, shrub layer and herb layer were 1,4 and 14, respectively. There were obvious differences among species diversity in tree layer, shrub layer and herb layer of the six communities, and the diversity indexes of shrub layer and herb layer were greater than that of tree layer. Species similarity index was generally low between different communities. P. tabulifor- mis community had the most abundant species in all layers and the dominance indexes were also greater than the other five. The dominant species of J. mandshurica community were outstanding in each layer, while the dominant species of T. chinensis community and Q. variabilis community were obvious in tree layer. P. tabuliforrnis community and P. massoniana community had abundant plant species diversity in all levels. P. rnassoniana community, J. mandshurica community and Q. variabilis community had rich seed- lings and saplings of constructive species in shrub layer. [Conclusion] T. chinensis community was on top of succession stage, and communities were quite stable. P. tabulaeformis community and P. massoniana community were rich in species and relatively complicated, so that the forest structure was stable. P. rnasso- niana community,J, mandshurica community and Q. variabilis community had great potential for natural regeneration. Thus, it is vital to strengthen the protection on these natural forest communities.