【摘要】 盐分含量高是影响赤泥堆场植物生长的主要限制因子之一。通过对一个20多年的赤泥堆场开展生态调查,研究了先锋植物盐分积累及分布特性。结果发现:赤泥堆场出现14种先锋植物;根系土Na~+平均含量为19.5 cmol/kg,这表明先锋植物具有较高的盐耐性;植物地上部分Na~+含量差异明显,马唐地上部Na~+含量仅0.84 cmol/kg,扫帚苗地上部Na~+含量高达39.7cmol/kg;马唐Na~+迁移系数为0.13,水柏枝的Na~+迁移系数高达2.92;扫帚苗和水柏枝的Na富集系数为2.66和3.29;狗牙根和马唐的Na~+积累系数分别为0.07和0.04;扫帚苗、水柏枝、狗牙根和马唐均可作为赤泥堆场植被重建的先锋植物。研究结果为赤泥土壤化和堆场生态重建提供了科学参考。更多还原

【Abstract】 Bauxite residue disposal areas(BRDAs) are physically degraded and hostile to plant growth. Nevertheless,natural plant colonization was observed in an abandoned BRDA in Central China. The pioneer plant species at the disposal area were identified, whilst distribution characteristics of salt ions such as Na~+, K+, and Ca2+ in plant tissues and rhizosphere residues were investigated. The mean concentration of exchangeable Na~+ in the rhizosphere soils was19.5 cmol/kg, which suggested that these pioneer plants had relatively high salinity resistance. Sodium content varied from 0.84 cmol/kg(Digitaria sanguinalis) to 39.7 cmol/kg(Kochia scoparia), whilst K to Na ratio varied from 0.71(Myricaria bracteata) to 32.39(Digitaria sanguinalis) in the shoots, which demonstrated that the salinity tolerance mechanisms of these pioneer species differed significantly. Accumulation factors of Na~+ in local plant species ranged from 0.04(D. sanguinalis) to 3.29(M. bracteata), whilst the translocation factor varied from 0.13(D. sanguinalis) to2.92(M. bracteata). The results suggested that four pioneer plant species including K. scoparia, M. bracteate, Cynodon dactylon and D. sanguinalis could be suitable for revegetation at other disposal areas.更多还原