不同营林措施对马尾松针叶养分的影响

对设置在贵州龙里、台江以及广西热带林业实验中心的不同施肥、不同密度、不同抚育措施、不同整地方式和不同种源马尾松人工林试验样地内针叶样品的Ｎ、Ｐ、Ｋ、Ｃa、Ｍg含量进行分析研究，结果表明，除广西施肥５年后，不同处理间针叶Ｎ、Ｍg两元素含量具有极显著差异外，其余措施对马尾松针叶养分含量的影响均未达到显著差异水平。因此，施肥具有调节马尾松针叶养分含量的作用；而不同造林密度林地内马尾松个体吸收养分的能力相同，则高密度易造成地力的快速衰退，对长期高密度造林的林地，应加以施肥，以维护土壤的持续利用；抚育措施并不影响林木养分的吸收；整地也未对马尾松吸收养分有多大影响；不同种源吸收养分的特点差异不大，因而优良种源加速林地地力的衰退。

Effects of Different Culture Measures on the Nutrition of Needle of Pinus massoniana

Studies were made on the N、P、K、Ca、Mg of the needles of Pinus massoniana in the samples of various density,fertilization,nursery measures,soil preparation methods and provenances,which are located in Longli、Taijiang and tropical Experiment Center of Guangxi.The results indicated:Except that the N、Mg of the needles of different treating which have been fertilized for five years in Guangxi,has significant differences,the rest measures have little effect on the nutrition of needles,their difference can't reach significant level.Therefore,fertilization has effect on adjusting nutrition of needles of Pinus mnassoniana,but Pinus massoniana tree in the forest of different cultivation density has the same ability to absorb nutrition,if it is cultivated in high density.The soil fertility will deline faster.To maintain the sustainable utilization of the soil,fertilization should be managed in high density forest.Various nursing measures and soil preparation methods have little effect on the absorbing of nutrition;difference of nutrition absorbing among different provenances is little,so plus provenance can accelerate deline of soil fertility.