莽山林区不同森林土壤氮、磷含量的研究

Research on nitrogen and phosphorus content in soil of different forest types in Mangshan

随着对森林土壤养分研究的逐渐深入以及森林养分对植被恢复、森林抚育中起的重要作用,人们开始发现不同森林类型下的森林土壤氮、磷这些主要养分元素分布具有很大差异性。文章主要通过采用野外定位监测与室内实验相结合的方法,对湖南莽山自然保护区不同林型土壤中的全氮、全磷和速效磷的垂直分布规律进行分析比较研究。结果显示:莽山7种不同林型土壤全氮平均含量大小的顺序为山顶矮林>高山矮林>竹林>杉木林>针叶林>常绿阔叶林>常绿针阔混交林。在土壤剖面垂直分布方面,除高山矮林外,其他林型下都是剖面表层含量最高,并随着剖面加深逐渐降低,呈现表层富集性。7种林型中高山矮林的全磷含量最高,而常绿针阔混交林最低。全磷的土壤剖面垂直分布差异明显,而有效磷的垂直变化较为平缓,且各个林型的有效磷含量差别较小。这主要和土壤母质、表层凋落物、海拔等因素有关。该研究结果对提高施肥效率、制定森林抚育对策有着重要的意义。

Considering the important role soil nutrients plays in vegetation restoration and forest tending, a deepening study was done to show that in different type of forest, distribution of some key nutrients like nitrogen and phosphorus have great differences. This article is mainly about some researches focus on the vertical distribution of total nitrogen, total phosphorus and available phosphorus in different type of forest soil, relevant data come from a combination method that includes field monitor in Mangshan nature reserve and some laboratory experiments. Results of these researches showed that the order of average total nitrogen content in 7 types of forest soil in Mangshan nature reserve is that Top coppice 〉 Alpine coppice 〉 Bamboo 〉 Chinese fir 〉 Coniferous forest 〉 Evergreen broadleaf forest 〉 Evergreen conifer. For soil profile vertical distribution aspect, expect for alpine coppice, in all other types of forest, total nitrogen reducing when it goes deepening and showing surface enrichment. As it for total phosphorus, alpine coppice has the highest content and evergreen conifer shows the lowest content. The soil profile vertical distribution of total phosphorus has great differences but the soil profile vertical distribution variation and content variation of available phosphorus in different types of forest are more gentle, it mainly relevant to parent soil material, surface litter, altitude and so on. These results in this article have great significance to fertilizer efficiency improvement, development of forest tending countermeasures.