热带森林土壤气态氮损失及其对水分添加的响应  

Nitrogen gaseous loss in tropical forest soil and its responses to water addition

作　　者：汤文广 周璋[1] 林明献[1] 李意德[1] 骆土寿[1] 陈德祥[1] TANG Wen-guang;ZHOU Zhang;LIN Ming-xian;LI Yi-de;LUO Tu-shouI;CHEN De-xiang(IResearch Institute of Tropical Forestry,Chinese Academy of Forestry,Cuangzhou 510520,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang,110016,China)

机构地区：[1]中国林业科学研究院热带林业研究所,广州510520 [2]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2018年第11期3231-3236,共6页Chinese Journal of Ecology

基　　金：中央级公益性科研院所基本科研业务费专项资金(RITFYWZX201401;RITFYWZX201404);海南尖峰岭森林生态系统国家定位观测研究站运行补助(2017-LYPT-DW-128)资助

摘　　要：量化土壤气态氮(N)损失对于森林生态系统N循环的研究具有重要作用。然而,关于气态N(特别是N_2)损失及其影响因子的研究相对较少。本文通过室内培养实验,研究了海南尖峰岭热带山地雨林土壤气态N损失及其对水分添加的响应。结果显示:在自然水分条件下,土壤气态N的损失速率相对较小,N_2O和N_2损失速率分别为-0.004～0.03和0～0.022 nmol N·h^(-1)·g^(-1);水分添加后,N_2O和N_2的损失速率分别剧增70倍和40倍以上。土壤气态N的损失也受森林类型及季节变化的影响,次生林土壤气态N损失速率大于原始林,雨季土壤气态N的损失速率大于旱季,但均不存在显著性差异。本研究结果表明,热带森林土壤气态N损失主要受土壤水分含量影响,为了准确估算热带森林土壤气态N损失,应该考虑由全球气候变化导致的强降水事件对土壤气态N损失的影响。Quantifying gaseous loss of soil nitrogen （N） is important for understanding forest ecosystem N cycling. However, relatively few studies have investigated N gas loss, especially N2. In this study, using a soil incubation experiment in laboratory, we examined soil N gaseous loss and its responses to water addition in two tropical montane forests in Jianfengling, Hainan Island. The results showed that in ambient soil water contents, soil N gas emission rates were relatively low,and N20 and N2 emission rates were -0.004-0.03 and 0-0.022 nmot N·h-1·g-1, respectively. After water addition, N20 and N2 emission rates increased sharply by more than 70 and 40 times, respectively. Soil N gas emissions were affected by forest types and seasons. N gas emission rates in secondary forest were higher than those in primary forest, and were higher in wet season than in dry season, but with no significant difference. Our results indicated that tropical forest soil N gaseous losses were mainly controlled by soil water content. In order to accurately estimate soil N gas losses of tropical forest ecosystems, we should consider the influence of heavy precipitation.

关 键 词：热带森林 气态氮损失 土壤水分 氮循环 

分 类 号：S714[农业科学—林学]