闽江河口湿地芦苇和互花米草生物量季节动态研究

Study on Biomass Dynamics of Phragmites australis and Spartina alterniflora in the Wetlands of Minjiang River Estuary

通过对闽江河口湿地芦苇（Phragmites australis）和互花米草（Spartina alterniflora）群落特征和生物量的调查，结果表明：2种植物株高和密度呈显著负相关。芦苇地上部各构件生物量最大值出现在夏季，其值为1524.8±78.85g·m^-2；互花米草最大值出现在秋季，其值为3037.2±248.78g·m^-2互花米草地上生物量显著大于芦苇（P〈0.05），但立枯量无显著差异（P〉0.05）。2种植物地下生物量均为0-15cm〉15-30cm〉30-60cm；芦苇夏季各层生物量极显著大于其他季节（P〈0.05），互花米草地下各层生物量在冬季达到最大，生长季节逐渐下降，夏季最小。芦苇和互花米草总生物量积累动态呈典型的单峰值曲线，总生物量互花米草高于芦苇，但二者差异不显著。随着入侵时间推移，互花米草总生物量还要持续增长。

Two populations, Phragmites australis and Spartina alterniflora growing in the wetlands of Minjiang River Estuary, were studied, in terms of their structural and biomass characteristics. The major findings were： for both, there was a significantly negative correlation between plant height and density; for Phragmites australis, the highest aboveground biomass was 1524.8±78.85 g·m^-2 , appearing in summer season, but for Spartina alterniflora the value would be 3037.2±248.78 g·m^-2 , and the season was autumn instead of summer; the aboveground biomass of Spartina alterniflora was significantly greater than that of Phragmites australis （P〈0.05）, but for withering biomass, no significant difference existed （P〉0.05）; for both, the belowground biomass decreased with depth （0-15 cm〉15-30 cm〉 30-60 cm）; for Phragrnites australis, the biomass in summer season was greatly higher than in other seasons, but for Spartina alterniflora, the peak season was winter, with its biomass gradually decreasing to the lowest point in summer; for both plants, the total biomass accumulation dynamics showed a single peak pattern within a year; and, the total biomass of Spartina alterniflora was higher, but not at significant level, than that of Phragrnites australis. Finally, it was predicted that the total biomass of Spartina alterniflora, which was identi-fled as a kind of invasive species for the study area, would continue to increase over time in the future.