金马河温江段河岸带不同生境植物物种多样性与土壤理化性质的动态变化

为评价植被恢复过程中生物多样性和土壤性质的变化,对2015和2018年金马河温江段河岸带内河滩地、砾石地、芦苇地、斑茅地和沙坑地5种生境的植物多样性和土壤理化性质进行了比较分析。结果表明,2015年金马河温江段河岸带共有32科80属113种草本植物,2018年共有57科118属161种草本、灌木植物,以河滩地和斑茅地的物种变化最显著,均有灌木层加入,而砾石地的变化最小。2018年除河滩地、斑茅地外,其余生境的物种多样性指数变化不大,各生境的物种丰富度指数(D)、Shannon-Wiener多样性指数(H)、Simpson优势度指数(H')、Pielou均匀度指数(Jsw)的变化趋势一致,均以砾石地最大,芦苇地最小。2018年河滩地、斑茅地的土壤含水量(SWC)显著低于其他生境,斑茅地的土壤容重(BD)最低,土壤全氮(TN)、有机质(OM)含量最大。冗余分析(RDA)表明,结合物种矩阵和环境矩阵,BD、SWC、OM与物种多样性的相关性最显著,砾石地和沙坑地主要受到SWC、土壤pH的影响,而在河滩地和斑茅地中OM是主导因子。从整体上看,禁止采砂后,各生境呈现不同程度的恢复状态,以斑茅地恢复效果最显著。这些为持续改善金马河河岸带土壤质量现状、促进河岸带生态系统恢复提供理论依据。

Dynamic Changes in Plant Diversity and Soil Physical and Chemical Properties in Different Habitats in Wenjiang Section of Jinma River

To evaluate the changes in biodiversity and soil properties during vegetation restoration, the plant diversity and soil characters among five habitats, such as flood land, gravel land, reed land, Saccharum arundinaceum land and sand land, in riparion zone of Wenjiang section of Jinma River were comparative analyzed in 2015 and 2018. The results showed that there were 113 species of herbs in Wenjiang riparion zone, belonging to 80 genera and 32 families in 2015, and 161 species of herbs and shrubs, belonging to 118 genera and 57 families in 2018. With shrub layer added in 2018, the changes in community structure of flood land and S. arundinaceum land were the most significant, and that in gravel land was the smallest. In 2018, except for the flood land and S. arundinaceum land, the biodiversity indexes had little change. The richness index (D), Shannon-Wiener diversity index (H), Simpson dominance index (H'') and Pielou evenness index (J_sw) showed the same variation trend among habitats, with the biggest in gravel land and the smallest in reed land. In 2018, the soil water contents (SWC) of flood land and S. arundinaceum land were significantly lower than that of other habitats, the soil bulk density (BD) of S. arundinaceum land was the lowest, but the contents of TN and OM were the biggest. Combining species matrix and environment matrix, redundance analysis (RDA) showed that BD, SWC, OM had the most significant correlation with species diversity. SWC and soil pH were the main effect factors in the gravel land and sand land, while OM in the flood land and S. arundinaceum land. On the whole, after forbidding sand mining, each habitat showed different degrees of restoration, and the restoration effect of S. arundinaceum land was the most significant. These would be conductive to providing theoretical basis for continuously improving the current situation of soil quality and promoting the restoration of riparian ecosystem in the Wenjiang section of Jinma River.