氧化铝赤泥堆场植物多样性

Plant species diversity in bauxite residue disposal areas

赤泥堆场是氧化铝工业生产过程产生的强碱性固体废弃物的堆存场所,是一种特殊的退化生态系统。选取华北地区3个典型赤泥堆场,开展植被调查及物种多样性研究,发现赤泥堆放20年后,出现先锋植物入侵现象。调查区域仅25种植物,隶属10科22属,其中禾本科和菊科植物占植物物种数的52%;草本植物占植物物种数的88%,其中一年生植物占物种数的56%;赤泥堆场植被稀疏、单位面积物种极少、物种丰富度和多样性较低,群落组成和结构简单,植物群落类型主要为虎尾草+狗牙根群落、虫实+狗尾草群落。狗牙根具有生长快、分布广、耐盐碱、适应性强等特点,可作为赤泥堆场植被重建先锋物种。研究结果为赤泥堆场生态修复和耐性植物的筛选提供了科学依据。

Bauxite residue is an alkaline waste by-product generated in the extraction of alumina from bauxite. Due to large volume and inherent environmental risk, the disposal of bauxite residue has become a major concern for sustainable development of the aluminum industry. Bauxite residue poses numerous physical and chemical limitations to plant establishment in disposal areas. Based on the on-the-spot investigation in bauxite residue disposal areas （BRDAs）, the important values and indices of plant species evenness and diversity were calculated. A total of 25 species were found naturally colonized in BRDAs. These species belong to 10 families and 22 genera, among which 14 species were annual. Gramineae and Compositae accounted for 52% of the total species. The plant community in BRDAs showed low species diversity and simple structures. The dominant types of plant community were Chloris virgata Sw. - Cynodon dactylon （L.） Pers community and Corispermum declinatum Steph ex Stev - Setaria viridis （L.） Beauv community. C. dactylon is a dominant species in some BRDAs which grows rapidly and has saline-alkaline tolerance, wide distribution, and a broad ecological amplitude. This species has potential in the revegetation of BRDAs.