摘要
采用野外封顶埋管法对兴安落叶松4种典型林型：草类-兴安落叶松林、赤杨-兴安落叶松林、杜香-兴安落叶松林、柴桦-兴安落叶松林土壤无机态氮及氮矿化速率变化特征进行了对比研究。结果表明：NH4-N是土壤有效氮的主要存在形式。NH4-N在无机氮中所占比例约为31％～82％，NO3-N在无机氮中所占比例约为18％～69％。4种林型土壤的氨化作用强于硝化作用，二者均是7月份活动最强烈，整个生长季中，氨化速率的变化范围是0．28～1．59μg·g～·d，硝化速率的变化范围是-0．28～1．18μg·g～·d。林型间差异不显著，氨化速率月份和林型之间没有显著的交互作用，硝化速率月份和林型之间有显著的交互作用（P〈0．0001）。4种林型土壤的氮矿化速率存在季节性变化，土壤平均矿化速率从大到小依次为：赤杨林（1．04±0．15）μg·g·d、杜香林（1．03±0．31）μg·g～·d、柴桦林（1．03±0．40）μg·g·d、草类林（1．02±0．22）μg·g～·d～。不同林型之间土壤氮矿化速率差异不显著，林型和月份之间有显著的交互作用（P〈0．02）。
The experiment was conducted to investigate the variations of inorganic nitrogen content and N mineralization in soil under four different tropical forests by the Close-Top Tube Incubation method in Daxing＇ an Mountain including Grass-Larix gmelini forest, Alnus-Larix gmelini forest, Ledum Sphagnum-Larix gmelini forest, Betula fruticosa-Larix gmelini forest. Ammonia nitrogen is the major form of inorganic nitrogen, the proportion of NH4 -N to the total inorganic is 31% -82% , and that of NO3-N to the total inorganic is 18% -69%. Soil ammonification rates and nitrification rates are the highest in July, and nitrification is the dominant process in the forests. Soil ammonification rates varies from 0.28 to 1.59 mg· kg-1 · d-l and that of nitrification rates varies from -0.28 to 1.18 mg · kg-1 · d-l , and the difference is not significant. Nitrogen mineralization rates show significant seasonal variations. Annual nitrogen mineralization rates in four forests are in the order of Alnus-Larix gmelini forest, （ 1. 04 ±0.15 ） mg · kg-1 · d-1 〉Ledum Sphagnum-Larix gmelini forest, （ 1.03±0.31 ） mg · kg-1 · d -1 〉Betulafruiteosa-Larix gmelini forest, （1.03±0.40） mg · kg-t ·d-I 〉Grass-Larix gmelini forest, （1.02±0.22） mg · kg-1· d-1. Soil nitrogen mineralization rate is not significant in different forest types, but the interaction in forest type and month is significant （P〈0. 02）.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2014年第4期60-64,共5页
Journal of Northeast Forestry University
基金
国家自然科学基金(309603170
40763002)
内蒙古自治区科技计划项目(20120421
20110527
20120419)
关键词
铵态氮
硝态氮
氮矿化速率
兴安落叶松林
Ammonium nitrogen
Nitrate nitrogen
Nitrogen mineralization
Larix gmelinii forest
