互花米草入侵对闽江河口裸滩湿地土壤有机碳的影响

Effects of Spartina alterniflora invasion on soil organic carbon in the bare tidal flat wetland of Minjiang River estuary

为揭示互花米草入侵对裸滩湿地土壤有机碳的影响,选取闽江河口裸滩湿地和被互花米草入侵的裸滩湿地为研究对象,测定其不同土层土壤的有机碳和活性有机碳质量分数,同时对土壤的各种理化性质进行测定分析。结果表明：裸滩和互花米草湿地0-60 cm土层土壤有机碳质量分数变化范围分别为0.95-12.43 g/kg和1.45-10.04 g/kg,平均质量分数分别为4.03和4.35 g/kg;互花米草湿地0-60 cm土层土壤微生物量碳、可溶性有机碳和轻组有机碳平均质量分数分别增加12.76%、40.86%和12.62%,土壤易氧化有机碳平均质量分数基本不变。研究结果表明互花米草入侵裸滩在一定程度上增加了土壤有机碳及不同活性有机碳质量分数,但影响并不显著。

This paper is devoted to disclose the effects of Spartina alterniflora invasion on soil organic carbon contents in the bare tidal flat. We chose the bare tidal flat and S. alterniflora wetlands of Minjiang River estuary as the research objects. The contents of soil organic carbon and soil labile organic carbon at different soil horizons of typical bare tidal flat and S. alterniflora wetlands were determined and the soil physicochemical properties were also analyzed. The results indicated that the contents of soil organic carbon at different soil depths（0- 60 cm） ranged from 0. 95 to 12. 43 g / kg in the bare tidal flat and and from 1. 45 to 10. 04 g / kg in S. alterniflora wetlands,with the mean values of 4. 03 and 4. 35 g / kg,respectively. Compared with the bare tidal flat,the mean contents of soil microbial biomass carbon,dissolved organic carbon and light fraction organic carbon in soils（0- 60 cm） of S. alterniflora wetlands increased by 12. 76%,40. 86% and 12. 62%,respectively. The contents of easily oxidizable carbon changed very little. The results of this study showed that the invasion of S. alterniflora had increased the contents of soil organic carbon and soil labile organic carbon,but the influence was not significant.