牛背梁自然保护区植物群落和针叶树小蠹虫群落物种多样性研究

Study on the Species Diversity of Plant Community and Coniferous Bark Beetles Community Diversity in Niubeiliang Nature Reserve

对牛背梁自然保护区的山麓农田-侧柏群落(群落Ⅰ),油松-华山松-锐齿栎群落(群落Ⅱ),油松-华山松-栓皮栎群落(群落Ⅲ),油松-华山松-辽东栎群落(群落Ⅳ),巴山冷杉-落叶松群落(群落Ⅴ),红桦-牛皮桦-巴山冷杉群落(群落Ⅵ)6种类型群落的高等植物及其针叶树小蠹虫的多样性等进行研究。结果表明在山麓灌丛群落至针阔混交林群落之间,物种多样性指数、群落均匀度指数和物种丰富度呈递增趋势;在中山针阔混交林群落与巴山冷杉和落叶松群落、红桦-牛皮桦-巴山冷杉群落之间,物种多样性指数、群落均匀度指数和物种丰富度呈下降趋势。从总体来看,森林植被的多样性程度高于灌丛和草甸,阔叶林则高于针叶林。群落优势度指数的变化规律则与之相反。不同森林群落类型中针叶树小蠹虫的多样性、均匀度和优势度研究结果表明针叶树小蠹虫群落物种多样性指数和均匀度由高到低的排列顺序依次为群落Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅰ;针叶树小蠹虫群落优势度的变化趋势与之相反。不同类型的森林植物群落中,针叶树小蠹虫群落结构及多样性存在明显差异。生态环境复杂,植被丰富的中山针阔混交林群落中,针叶树小蠹虫多样性和均匀度指数均较大,但优势度指数低,小蠹虫大发生的几率较小。加强管理,促进森林生态系统的多样性和稳定性,对提高植物群落自身调控害虫种群数量具有重要意义。

The species diversity of higher plants and coniferous bark beetles in hilly cultivated land （community Ⅰ ）. P/nus tabulaeformis- P. armandi - Quercus aliena var. acuteserrata （community Ⅱ ）, P. tabulaeforrnis - P. armand - Q. variabilis （community Ⅲ ）, P. tabulaeforrnis - P. armandi - Q. liaoiungensis （community Ⅳ ）, Abies fargesii - Larix potaninii （community Ⅴ ） and Betula albosinensis - B. utilis - A . fargesii （community Ⅵ ） in Niubeiliang Nature Reserve were studied. The result showed that from shrub communities to mixed coniferous and broad-leaved forest communities, the Shannon-Wiener＇s diversity index, Pielou＇s evenness index and species richness presented an increasing trend ; but from mixed coniferous and broad-leaved forest communities to alpine coniferous forest communities and alpine meadow communities, the Shannon- Wiener＇s diversity index, Pielou＇s evenness index and species richness presented an decreasing trend. View the situation as a 6： whole, the diversity of forest communities is higher than that of shrubs and meadow communities, the diversity of the deciduous broad-leaved forest is higher than that of coniferous forest. However, the Berger-Parker＇ s dominance index presented a trend just on the contrary compared to Shannon-Wiener＇ s diversity index, Pielou＇ s evenness index and species richness. The result of species diversity of bark beetles in different forest communities showed that the species diversity and evenness indices decreased in the following sequence： community Ⅱ , community Ⅲ , community Ⅳ, community Ⅴ , community Ⅵ and community Ⅰ. However, the dominance index presented a trend just on the contrary compared to diversity index and evenness index. On the basis of natural geography and vegetation, the plant communities and coniferous bark beetles communities diversity were compared in Niubeiliang Nature Reserve, the results indicated that： in different forest plant communities, the diversity of bark beetles had much difference. The result also showed that in the mixed coniferous and broad-leaved forest communities which had complex ecological condition and abundant vegetation, the Shannon-Wiener＇ s diversity index, Pielou＇s evenness index and species richness of bark beetles were higher than those in other communities. Because the dominance index was lower than those in other communities, so it was hard to found a breakout of bark beetle in the mixed coniferous and broad-leaved forest communities. These indicated that the ecological management measures which promote the diversity and stability of forest ecosystem were of far reaching importance in improving automatic control of pest population.