鼎湖山马尾松针阔叶混交林土壤有效氮动态的初步研究  

A preliminary study on the dynamics of bio-available nitrogen in soils of pine-broadleaf mixed forest in Dinghuashan Biosphere Reserve

作　　者：莫江明[1] 彭少麟[1] 方运霆[1] 郁梦德[1] 孔国辉[1] 张佑昌[1] 

机构地区：[1]中国科学院鼎湖山森林生态系统定位研究站,广东肇庆鼎湖526070

出　　处：《生态学报》2001年第3期492-497,共6页Acta Ecologica Sinica

基　　金：国家自然科学重大基金! ( 39899370 );中国科学院院长基金

摘　　要：用离子交换树脂袋法测定了鼎湖山生物圈保护区马尾松针阔叶混交林土壤有效氮变化情况。鼎湖山马尾松针阔叶混交林土壤各季节平均总有效氮 (铵态氮 +硝态氮 )在 1 8.87～ 93.2 0μg/d· g干树脂之间 ,且具有明显的季节性变化特点。然而 ,这些季节性变化根据土层和有效氮组分的不同而异。总有效氮主要由铵态氮组成 ( >90 % )。总有效氮和铵态氮在土层 0～ 1 0 cm和 1 0～ 2 0 cm之间各个季节均无显著的差异 ,但硝态氮在春、夏两季差异较大 ,尤其在夏季两土层之间的差异达显著水平 ( P<0 .0 5)。在本研究样地中 ,硝化速率受铵态氮供应的影响不甚明显。与同一地区的马尾松纯林和阔叶混交林比较 ,硝态氮为 :针叶纯林 <针阔叶混交林 <阔叶混交林 ;铵态氮则为 :针阔叶混交林〉针叶纯林 >阔叶混交林。The dynamics of bio\|available nitrogen in soils of pine\|broadleaf mixed forest in Dinghushan Biosphere Reserve were studied using the ion exchange resin bag method.The total available nitrogen (NO\-3\+-\|N+NH\-4\+-\|N) in different seasons ranged from 18.87 to 93.20μg/d·g dry resin and showed significantly seasonal variation depending on different components of available nitrogen and at different depth of soil.It was the highest in the spring season.The available nitrogen in soil was mostly composed of ammonium nitrogen (>90%).No significant differences in soil ammonium N concentrations between the two studied soil layers (0~10cm,10~20cm).However,there were significant differences in nitrate N concentrations in summer between the two layers.The positive correlation between ammonium N and nitrate N in this forest was significant only in one season.

关 键 词：有效氮 离子交换树脂法 马尾松针阔叶混交林 鼎湖山 土壤 

分 类 号：Q948.11[生物学—植物学]