排土场复垦初期种群生态位与多样性动态分析

Dynamic analysis of niche and diversity of populations in the early stage of dump reclamation

为了研究露天煤矿排土场土地复垦初期群落演替特征,采用空间代替时间的方法,研究了露天煤矿排土场土地复垦3年主要植物种重要值、生态位宽度、物种间生态位重叠及植物多样性指数的变化情况。结果表明:紫花苜蓿、无芒雀麦和披碱草等植物的重要值与生态位宽度逐年提高,而油菜、燕麦草等植物重要值与生态位宽度则降低;土地复垦第2年与第1年相比生态位重叠值(O_(ik))总体提高0.297,第3年较第2年总体降低0.065,物种在资源利用上的相似性和竞争性先增强后减弱;在排土场土地复垦前3年时间里,植物种由29种提高到74种,Margalef丰富度指数提高了1.10倍。总体上,在矿区重建生态系统演替初期,演替速度迅速,并在进行土地复垦后的第3年群落结构开始趋于稳定。

In order to study the community succession characteristics in the early stage of land reclamation in surface coal mine dump,the method of space replacing time was adopted.The important value of main plant species,niche breadth,niche overlap among species and the change of plant diversity index in three years of land reclamation in surface coal mine dump were studied.The results show that the importance value and niche breadth of alfalfa,bromus inermis and elymus dahuricus increased year by year,while the important values and niche breadth of rape and oat grass,and other plants decreased.Compared with the first year,the niche overlap value(O_(ik)) in the second year of land reclamation increased by 0.297,and decreased by 0.065 in the third year.The similarity and competitiveness of species in resource utilization first increased and then decreased.In the first three years after land reclamation of the dump,the plant species increased from 29 to 74,and the Margalef richness index increased by 1.10 times.In general,the succession rate of the reconstructed ecosystem in the mining area was rapid in the early stage,and the community structure began to stabilize in the third year after land reclamation.