塞罕坝国家级自然保护区不同森林类型植物物种多样性比较

摘要

In order to protect effectively the understory plant resources,diversity indices,including species richness,important value,Simpson index,evenness index etc.,were used to analyze woody and herbaceous plants diversity of five forest types in Saihanba National Nature Reserve.Results indicated that the understory plant diversity was much higher in broadleaved forests (53±7.000) than in coniferous forests (34±7.071) in the study area.For herbaceous plant species,Simpson and Shannon-Wiener indices were the highest in Quercus mongolica forests (0.88 and 2.58) and the lowest in Picea meyeri forests (0.62 and 1.41),respectively,For woody plant species,Simpson and Shannon-Wiener indices were the highest in Populus davidiana forests (0.52 and 0.97) and the lowest in Quercus mongolica forests (0.12 and 0.20),respectively.The above results were attributed to the differences in terms of tree species composition,stand density and management mode between broad-leaved and coniferous forests.The diversity of woody plants was lower than that of herbaceous plants in different forest types.Species diversity was largely determined by herbaceous plants in forest communities.Accordingly,some works such as reasonable pruning and regular tending for coniferous plantations,strict conservation and improvement of natural regeneration for natural broad-leaved forests,are indispensable in effective protection of the understory plant resources in the study area.%为了更好地保护林下植物资源,以塞罕坝国家级自然保护区内的5种森林类型为研究对象,运用丰富度、重要值、Simpson指数、均匀度指数等对其木本植物和草本植物物种多样性进行研究.结果表明:在研究区阔叶林的物种丰富度(53±7.000)高于针叶林(34±7.071).草本植物Simpson和Shannon-Wiener指数在蒙古栎林中最高、白杆林中最低,分别为0.88、2.58及0.62、1.41;木本植物Simpson和Shannon-Wiener指数在山杨林中最高、蒙古栎林中最低,分别为0.52、0.97和0.12、0.20.造成这些差异的原因可能与树种组成、经营方式和林分密度有关;塞罕坝自然保护区内的不同森林类型木本植物多样性低于草本植物,森林群落多样性的高低在很大程度上由草本植物决定.建议对保护区内人工针叶林采取合理修枝和定期抚育;对天然阔叶林加强保护,保持群落的天然更新.