施氮对杉木苗生物量及光合特性影响的研究

杉木１９个不同家系苗木施氮试验结果表明：在不追加氮的自然生长状况下，三明５４、三明５６、三明５８三个家系生物量最大，表现最优；杉木苗期施氮对生物量影响显著；不同家系对氮素要求不同，有些家系对氮素要求高，宜多施氮肥，有些家系对氮素要求低，不宜多施氮肥；杉木苗木的生物量与叶绿素含量、净光合速率呈正相关，生长良好的家系叶绿素含量、净光合速率较高；苗期施氮能提高叶绿素含量，其叶绿素反应趋势与生物量反应趋势一致，说明苗木的生理活动是苗木生长状况的决定因素。

Effects of Supplying Nitrogen Element on the Biomass and Photosynthetic Characteristics of Chinese Fir Seedling

An experiment of supplying nitrogen element to seedlings of 19 different Chinese fir families was conducted. The results indicated that the biomasses of three families seedlings of Sanming 54, Sanming 56 and Sanming 58 were the highest under natural condition (not supplies with N ). The effects of supplying nitrogen on different families seedlings biomasses showed significant difference, some families seedlings needed supplying more nitrogen, others less. The biomasses were postive relative to the chlorophyll contents and the net photosytheticis rates, the desirable families had higher chlorophyll contents and higher photosynthetic rate. Supplying nitrogen during seedling stage could increase the chlorophyll content but the degree in different families showed significant difference.