大兴安岭火烧迹地植被恢复中植物多样性与生物量分配格局
Plants diversity and biomass distribution of vegetation restoration in burned area of Great Xing’an Mountains.
-
摘要: 为了探讨火烧迹地植被恢复中植物多样性和生物量及二者关系,采用时空互代法,以大兴安岭重度火烧迹地不同恢复年限落叶松人工林为研究对象,以天然白桦林作为对照样地,对乔木层、灌木层、草本层和群落物种多样性指数及生物量进行了研究。结果表明:1)植被恢复过程中,草本层丰富度指数(Margalef指数)、Shannon-Wiener指数和均匀度指数(Pielou指数)高于乔木层和灌木层,群落物种多样性呈波动式变化,恢复21年群落Margalef指数和Shannon-Wiener指数最高,恢复13年群落Pielou指数最高。植被恢复过程中群落多样性指数均高于天然白桦林。2)植被恢复过程中群落生物量为10.80~123.96 t/hm2,随恢复年限的增加逐渐增大,恢复21和24年群落生物量高于天然白桦林。草本层生物量占群落生物量比例最低,恢复3年群落枯落物层蓄积量占群落生物量比例最高,其余恢复年限乔木层生物量占群落生物量比例最高。3)乔木层Margalef指数与生物量呈极显著正相关。灌木层Shannon-Wiener指数和Pielou指数与生物量呈极显著负相关,Pielou指数与生物量相关系数最高。草本层多样性与生物量相关性不显著。群落Shannon-Wiener指数与地表生物量呈极显著负相关。由此可知,人工更新灌木层和草本层多样性恢复效果优于天然更新,人工更新恢复21和24年的生物量恢复效果优于天然更新,植被恢复过程中植物多样性和生物量存在一定相关性。Abstract: In this study, we used the method of time-space mutual substitution in order to explore plant species diversity, biomass and their relationship in the process of vegetation restoration of burned areas. Compared with natural Betula platyphylla forest, Larix gmelinii plantation of different restoration years in severely burned area of Great Xing’an Mountains were selected as research object. The species diversity index and biomass of tree layer, shrub layer, herb layer and community were studied. The results showed that: 1) In the process of vegetation restoration, the Margalef richness, Shannon-Wiener and Pielou evenness indices of herb layer were higher than those of tree and shrub layers, but community species diversity fluctuated. The Margalef richness and Shannon-Wiener indices of the plantation restored after twenty-one years was the highest, and the Pielou evenness index of the plantation restored after thirteen years was the highest. 2) The biomass of community in the process of vegetation restoration was 10.80--123.96 t/ha, and it gradually increased with the increase of restoration years. The biomass of plantation restored after twenty-one and twenty-four years were higher than natural B. platyphlla forest. The biomass of herb layer accounted for the lowest proportion of community biomass. Restored after three years, litter storage capacity accounted for the highest proportion of community biomass. During other restoration years, tree layer biomass accounted for the highest proportion of community biomass. 3) The Margalef richness index of tree layer was very significantly positively correlated with biomass. The Shannon-Wiener and Pielou evenness indices of shrub layer were significantly negatively correlated with biomass. While the correlation coefficient of evenness index and biomass was the highest. Species diversity and biomass of herb layer were not significantly correlated. The Shannon-Wiener index of community was significantly negatively correlated with surface biomass. In conclusion, the diversity recovery effect of shrub and herb layers of artificial regeneration was better than natural regeneration. And the biomass recovery effect of artificial regeneration restored after twenty-one and twenty-four years was better than natural regeneration. In the process of vegetation restoration, the plant diversity and biomass had certain relevance.