Abstract: This paper deals with the contents, pool amounts and annual dynamics of Si element in Dendrocalampsis oldhami forest in south Fujiqn, China. The results were as follows:1. Si element contents (% dw) varied in various fractions of Dendrocalameopsis oldhami forest. The range of contents was 0.208%~ 6.346% and the order in various fractions was leaf> fine root> branch> rhizome> stem.2. The pool amounts of Si element in the standing crop of biomass were 261.168 g/m², in which those of aerial part were 207.385 g/m² (accounting for 79.41%)and those of under ground portion were 53. 783 g/m² (20.59%). The distribution of aerial part were higher than those of under ground portion in Dendrocalamopsis oldhami forest.3. Si element contents of Dendrocalameopsis oldhami leaves tended to increase from summer to winter, with the exception of that in November 1996; the highest was in February 1997; but Si element contents decreased gradually in spring, the lowest was in May 1997.4. Si element contents continually released and accumulated from decomposing fine roots in Dendrocalamopsis oldhami forest from July 1996 to June 1997.

Key words: Dendrocalamopsis oldhami, Si element dynamics

摘要： 研究了闽南绿竹(Dendroca lamops is oldhami)林硅素的含量特征、库存量及年动态。结果表明:1.绿竹林各组分硅素含量有较大差异,分布很不均匀。含量范围在0.208%~6.346%之间,各组分的含量大小顺序是:叶 >细根 >枝 >根茎 >杆;2.绿竹林硅素的现存库存量为261.168 g/m²,其中地上部为207.385 g/m²(占总现存库存量的79.41%),地下部为53.783 g/m²(占20.59%);硅素在地上部的分布量高于地下部;3.绿竹叶硅素含量从夏季到冬季呈上升趋势,2月达最高,而后在春季逐渐下降,到5月降至最低。植物体内硅素的累积,主要是通过对蒸腾流内单硅酸的被动吸收来实现的;4.绿竹细根分解过程中硅素含量处在释放和累积的相间波动之中。

关键词: 绿竹, 硅素动态