中文摘要：

探讨入侵种互花米草（Spartinaalterniflora）对闽东滨海红树林湿地生态系统的影响，揭示互花米草的入侵机制，采用空间替代时间的研究方法，对闽东滨海湿地互花米草入侵不同阶段的群落类型（秋茄（Kandeliacandel）红树林群落、秋茄红树林-互花米草共生群落、互花米草群落和光滩）土壤有机碳（TOC）的演化进行研究。结果表明：1）水平变化：4个不同入侵阶段TOC大小次序为：秋茄红树林群落〉秋茄一互花米草群落〉互花米草群落〉光滩，且秋茄红树林群落0-60cm土层深度有机碳平均值24．8g·kg-1，互花米草群落则为11．73g·kg-1，说明互花米草入侵闽东滨海红树林湿地有可能大大削弱该生态系统的碳汇功能。4个不同群落类型0-20cm土层深度的TOC不具有显著性差异（P〉0．05），但20-40cm、40-60cm土层深度具有显著性差异（P〈0．05）；2）垂直变化：除互花米草群落TOC在40-60cm土层达到最大外（P〉0．05），其他3个群落类型都是在20-40cm土层深度达到最大（P〉0．05）；3）相关性：土壤容重与土壤含水量存在极显著的负相关性（P〈0．01），TOC和土壤容重存在极显著的负相关性（P〈0．01），TOc与土壤含水量存在极显著的正相关性（P〈0．01）。

英文摘要：

Spartina alterniflora is a world wide notorious invasive plant that has colonized large areas since it was introduced into China in 1979. Its powerful genetic differentiation ability and resistance to adversity contribute to its invasiveness. In order to clarify the effect of invasive S. alterniflora on east- ern Fujian coastal wetlands, the content of soil organic carbon （SOC） at different intrusion stages were determined and analyzed. The horizontal change of Kandelia candel community （KC）, symbiotic com- munity （SC）, S. alterniflora community （SC） and barren mudflat （B） varied between 24. 63 and 24.90 g. kg 1, 11.39 and 12.32g· kg-1, 11.48and11.92 g. kg-l and 10.29 and 10.55 g· kg-1, re- spectively. S. alterniflora invasion to eastern Fujian coastal wetland will greatly weaken the ecosystem carbon sinking function. Different intrusion stages do not had significant effect in 0420 cm （P〉0.01）. While 20～40 cm,40～60 cm had significant effect （P〈0.01）. For the vertical change, the highest val-ue of S. alterniflora community SOC occurred in 40～60 cm where the SOC accumulated by 24.90 g · kg -1（P〉0.05）. However, the other intrusion stages reached the highest value in 20440 cm （P〉 0.05）. The SOC was significantly and positively correlated （P〈0. 01） with soil moisture content; however it significantly but negatively correlated （P〈0.01） with soil bulk density.