浙闽沪滨海感潮沼泽主要草本植物生物硅含量特征

Biogenic Silica Contents in Herbaceous Plants of Coastal Tidal Marshes in Fujian Province,Zhejiang Province and Shanghai City

硅元素是植物生长发育必需的生源元素之一,在湿地生物地球化学循环中起着重要作用。在福建省、浙江省和上海市的18处滨海感潮沼泽中,采集主要的草本植物样品,测定其生物硅含量。研究结果表明,同一种植物的生物硅含量在不同纬度的河口或海湾差异显著,呈线性变化规律;在区域尺度,不同草本植物的生物硅含量差异明显,禾本科(Poaceae)植物芦苇(Phragmites australis)、互花米草(Spartina alterniflora)和莎草科(Cyperaceae)植物短叶茳芏(Cyperus malaccensis)、海三棱藨草(Scirpus mariqueter)、藨草(Scirpus triqueter)的生物硅含量显著高于藜科(Chenopodiaceae)植物南方碱蓬(Suaeda australis),其中芦苇的生物硅含量[(43.3±3.5)mg/g]最高,南方碱蓬的生物硅含量[(5.1±0.6)mg/g]最低;同种植物不同器官的生物硅含量也具有显著差异,互花米草叶片和叶鞘的生物硅含量显著高于茎和穗,芦苇叶鞘的生物硅含量显著高于叶片、茎和穗;互花米草、芦苇、短叶茳芏和南方碱蓬植株的生物硅含量随着纬度增加呈降低趋势,但是与降水量无显著相关性;协方差分析表明,气温是影响不同纬度间滨海感潮沼泽草本植物生物硅含量差异的主要气候因子。

Silicon is one of the essential biogenic elements for plant growth and development,and plays an important role in the biogeochemical cycle of wetland.In 18 coastal tidal marshes of Fujian Province,Zhejiang Province and Shanghai City,samples of major herbaceous plants were collected and their biogenic silica contents were determined.The results showed that the biogenic silica contents of the same plant varied significantly across estuaries and bays at different latitudes,and showed a linear pattern of variation.At the regional scale,the biogenic silica content of different herbaceous plants varied significantly.The biogenic silica contents of Poaceae plants(Phragmites australis and Spartina alterniflora)and Cyperaceae plants(Cyperus malaccensis,Scirpus mariqueter and Scirpus triqueter)were significantly higher than those of Chenopodiaceae plant(Suaeda australis).The biogenic silica content of Phragmites australis was the highest,and the mean value was(43.3±3.5)mg/g,while the biogenic silica content of Suaeda australis was the lowest,the mean value was(5.1±0.6)mg/g.The biogenic silica content in different organs of the same species also had significant differences.The biogenic silica contents in the leaves and leaf sheaths of Spartina alterniflora were significantly higher than those in the stems and spikelets.The biogenic silica contents in the leaf sheaths of Phragmites australis were significantly higher than those in the leaves,stems and spikelets.In the subtropical China,the biogenic silica contents of Spartina alterniflora,Phragmites australis,Cyperus malaccensis and Suaeda australis decreased with increasing latitude,but were not significantly correlated with precipitation.The results of covariance analysis indicated that temperature was the main climatic factor affecting the variation of biogenic silica contents of herbaceous plants in coastal tidal marshes at different latitudes.