不同林龄油松和白扦林地植物多样性分析

Plant diversity of Pinus tabulaeformis and Picea meyeri at different stand ages

为探明不同林龄的油松和白扦林地植物多样性的变化规律并确定影响其变化的因子,以物种丰富度指数、物种多样性指数和物种均匀度指数作为衡量植物多样性的标准,研究内蒙古兴和县二道营流域友谊水库不同林龄油松和白扦水土保持林地的生物多样性特征及其影响因子。结果表明:1)油松人工林植物多样性指数大于白扦人工林,草本群落生物多样性随林龄的增加呈现出非线性增长趋势。5年生油松林的草本群落生物多样性指数最高,为2.09;13年生油松最低,仅1.63。白扦人工林的Margalef指数高于油松林地,13年生白扦人工林的Margalef指数最高,为3.79;2年生油松的Margalef指数最低,仅为2.16。2)在植被恢复演替进程中,多年生草本逐渐替代一年生草本,演替朝正方向进行。3)在众多土壤因子中,土壤水、土壤抗冲性及土壤有机碳质量分数对生物多样性指数起直接作用。研究结果可为森林草原过渡区域植被恢复与重建提供必要的理论支撑。

In order to explore the change law of plant diversity in Pinus tabulaeformis and Picea meyeri stands at different stand ages and figure out the driving factors for plant diversity,we took Margalef index,Simpson index,Shannon-Wiener index and Pielou index as criteria for measuring biodiversity. We analyzed and compared the characteristics of biodiversity and soil physico-chemical properties of Pinus tabulaeformis stands and Picea meyeri stands at different stand ages in Youyi Reservoir,Erdaoying Basin,Xinghe County of Inner Mongolia. The results indicated that： 1） The biodiversity index of Pinus tabulaeformis artificial forest was greater than that of Picea meyeri artificial forest. The biodiversity of herbaceous community presented a nonlinear rising tendency with the increase of forest stand age. Fiveyear-old Pinus tabulaeformis forest had the highest biodiversity index of 2. 09,whereas the biodiversity index of the thirteen-year-old forest was the lowest,only 1. 63. The Margalef index of Picea meyeri artificial forest was higher than that of Pinus tabulaeformis forest,3. 79 in thirteen-year-old Picea meyeri and 2. 16 in two-year-old Pinus tabulaeformis artificial forest. 2） During the process of vegetation restoration succession,perennial herbs replaced annual herbs gradually,ongoing towards a positive direction. 3） Among various edaphic factors,the content of soil water,soil anti-scouring ability and SOC had direct effects on biodiversity index. The results of our study could provide a theoretical support for vegetation restoration and rehabilitation in the forest-steppe ecotone.