两种根蘖型植物根系构型对典型草原退化演替的生态适应性研究.pdfVIP

摘 要 根蘖型植物在草地退化过程中占有重要的地位。本文选择了锡林郭勒典型草原区 的轻度、中度、重度和极度四个退化水平的植物群落，在分别对各群落的土壤水分、 容重、硬度及植物群落调查的基础上，通过比较群落中的根蘖型植物二裂委陵菜 (Potentilla bifurca)和星毛委陵菜(Potentilla acaulis)与非根蘖型的8 种植物(分属于轴根 型、根茎型、密丛型及须根型) 的根表面积、总根长和根总体积等 11 个根系构型参数 及根幅、根深和地下生物量等相关参数，研究了根蘖型植物根系构型对草地退化的生 态适应性原理，得出以下结论：① 11 个根系构型参数中，在表明 5 种根系构型对土 壤水分、容重和硬度的综合适应能力方面，根表面积最强，其次是总根长，再次是根 总体积和根分叉数。② 直径 3.0 –3.5 mm 的粗根，对二裂委陵菜的根表面积影响显著， 而直径 1.5 mm 以下的细根对星毛委陵菜的根表面积影响显著。③ 阔腰倒锥体三维根 系构型是星毛委陵菜适应草原退化并使之成为建群种的优势构型。 研究结果显示，典型草原群落中，随群落退化程度的加剧，根蘖型植物二裂委陵 菜和星毛委陵菜在群落中的重要值和相对优势度逐渐增加，发挥的生态作用逐渐增 强，体现出该根系构型较非根蘖型根系构型更强的综合生态适应优势，表明这两种植 物在植被恢复和遏制草地退化方面具有独特的优势作用。 关键词: 根蘖型植物；根系构型；退化群落；二裂委陵菜；星毛委陵菜 Study of ecological adaptation of root architecture of two creeping-rooted plants to degradation succession in the typical steppe Abstract Creeping-rooted plants play an important role in the process of steppe degradation. The steppes with different degradation level (L, M, H and E) at typical steppe in Xilingol of Inner Mongolia were selected; parameters including the soil moisture, soil bulk density, soil hardness and plant community were investigated. Parameters of creeping-rooted plants (Potentilla bifurca and Potentilla acaulis) and non-creeping rooted plants (including 8 species with different types of root— axis-rooted type, rhizome type, dense cluster-type and fibrous root-type) were compared. The parameters includes 11 root architecture indexes and root width, root depth with belowground biomass et al. The results were shown as follow: First, among 11 parameters of root architecture, root surface area had the strongest ability to explain the comprehensive adaptability to soil environment of five types of root architecture, following the t