红树林恢复对海岸湿地土壤影响的初步研究

Preliminary studies on effects of restored mangroves on coastal soils

初步研究了不同林龄的再植红树林对海岸湿地土壤理化性质的影响。结果表明,红树林恢复对深层土壤(20～25cm)的影响强于表层(0～5cm);与光滩相比,红树林恢复对表层土壤的氧化还原性无显著影响,但导致20～25 cm土层氧化性增强;再植红树林对土壤营养盐有明显吸收作用,其中NH4+-N含量显著高于NO2--N 和NO3--N,为主要吸收营养盐,PO43--P含量虽与IN相当,但红树林对P的吸收并不明显;随着红树林恢复时间的延长(林龄增加),20-25 cm土层的pH值显著下降,红树林酸化作用增强;各样地表层土壤SO42-含量无显著差别,但恢复林地深层土壤明显高于光滩。

Effects of mangroves restored in different years on physical and chemical properties of coastal soils were studied. Results showed that the effects on deep soils (20-25cm) were more significant than surface soils (0-5cm). Eh values of 20-25cm soils under mangrove forests were higher than those of barren soils. Restored mangroves strongly assimilated nutrients from soils to accelerate their growth. The contents of NH4+-N were higher than those of NO2--N and NO3--N and NH4+-N was the main inorganic nitrogen assimilated by mangroves. Although its contents were nearly the same as the inorganic nitrogen, PO43--P was assimilated little. As mangroves grew, pH values at depth of 20-25cm decreased significantly and soil acidification was strengthened. There was no significant difference in SO42- contents among the surface soils but at depth of 20-25cm, the contents of the soils under mangrove forests was higher than those of barren soils.