摘要
以闽江口潮滩湿地为研究对象,由岸及海方向对芦苇、短叶茳芏、互花米草(潮沟内)和互花米草(潮沟外)4种湿地土壤生物硅和土壤间隙水氮硅营养盐含量及其随深度变化的特征进行为期1a的季度观测。结果显示:互花米草(外)、短叶茳芏、芦苇和互花米草(内)带湿地土壤生物硅的年均含量依次降低,分别为14.33、10.40、9.98、7.50 mg/g;互花米草(外)、互花米草(内)、短叶茳芏和芦苇带湿地土壤间隙水活性硅酸盐年均含量依次降低,分别为407、359、344、323μmol/L;湿地各植被带土壤及间隙水含硅量均呈现夏秋季节高于冬春季节的趋势。统计分析表明:间隙水活性硅酸盐与土壤生物硅含量、距潮沟的距离之间的正相关性均比较显著(P<0.05),温度对土壤中硅含量的影响也有一定的正相关性,说明湿地植被、温度和潮汐作用是影响闽江口湿地硅分布的重要因素。与土著种对比,互花米草入侵在一定程度上改变了闽江口潮滩湿地土壤硅分布的格局。
Silicon （Si） is an essential nutrient for many plants as well as an important element that controls the functions of terrestrial and aquatic ecosystems. Wetland ecosystems are considered to be very important for Si transport and transformation in nutrient biogeochemical cycles. However, information on Si cycling in wetland ecosystems is scarce. The Shanyutan wetland is the largest tidal wetland in the estuary of the Min River, southeast China. In this study, the Si distribution pattern and its influencing factors were determined by seasonally measuring the levels of dissolved silicates （DSis） in the porewater and malaccensis wetland （CMW） , comparison, three sampling si biogenic silica （BSi） in the sediments of Phragmites australis wetland （PAW）, Cyperus and Spartina alterniflora wetland （SAW） from October 2012 to September 2013. For better tes were added in SAW since January 2013; these sites were isolated by a 30m wide tidal creek. The sampling sites near the land were marked as S. alterniflora wetland （ inside ; SAWI）, whereas those near the sea were marked as S. alterniflora wetland （outside; SAWO）. The results indicated that the average contents of BSi were 14.33 mg/g in SAWO, 10.40 mg/g in CMW, 9.98 mg/g in PAW, and 7.50 mg/g in SAWI. The average concentrations of DSis in the sediment porewater were 407 μmol/L in SAWO, 359 μmol/L in SAWI, 344 μmol/L in CMW, and 323 μmol/L in PAW. Generally, the contents of BSi in the sediments and DSis in the porewater were higher in summer and autumn, whereas they were lower in spring and winter. Statistical analysis revealed significantly positive correlations between DSi concentration in the porewater and BSi content in the sediments or the distance from the shoreside to the tidal creek （P〈 0.05 ）. BSi content in the sediments was slightly positively correlated with temperature. Taken together, our findings suggest that the distribution of Si in the wetlands of the Min River estuary was correlated with vegetation, temperature, and tidal action. Unlike that of native species, the invasion of S. alterniflora, to some extent, altered the distribution patterns of Si in the wetlands.
出处
《生态学报》
CAS
CSCD
北大核心
2016年第21期6766-6776,共11页
Acta Ecologica Sinica
基金
国家自然科学基金项目(41401114)
福建省教育厅项目(JA14082)
关键词
生物硅
活性硅酸盐
间隙水
潮滩湿地
闽江口
biogenic silica
dissolved silica
porewater
tidal wetland
Min River estuary
