摘要
为探究氮(N)沉降和凋落物输入量改变对凋落叶分解的影响,该研究于2014年6月至2019年6月,以华西雨屏区处于N饱和状态的常绿阔叶林为研究对象,设置N添加和凋落物处理双因素实验,其中N添加处理分别为对照(CK,0 kg·hm^(-2)·a^(-1))、低N(LN,50kg·hm^(-2)·a^(-1))和高N(HN,150kg·hm^(-2)·a^(-1)),凋落物处理分别为凋落物输入量不变(L0,不改变凋落物输入),减少(L-,减少50%)以及增加(L+,增加50%)。结果表明:6年N添加处理对该森林生态系统地上凋落物产量影响不显著;N添加处理显著抑制凋落叶分解,且N添加量越高,凋落叶分解抑制作用越强;N添加显著降低分解后期凋落叶中锰(Mn)的残留率,促进Mn的释放;凋落物输入量的增减处理未显著改变凋落叶分解速率,而凋落物增减处理升高了凋落叶中Mn的残留率,减缓Mn的释放;N添加和凋落物处理交互作用不显著。该研究表明亚热带N饱和常绿阔叶林凋落叶分解受N沉降的直接影响显著,凋落物处理主要影响凋落物分解过程中Mn的含量,并且凋落物Mn含量在凋落物分解响应N输入的过程中可能起着关键作用。
Aims The purpose of this study is to examine the responses of litter decomposition to nitrogen(N)deposition and aboveground litter manipulation.Methods A two-factor experiment of N addition and litterfall manipulation was performed in a N saturation evergreen broadleaf forest on the western edge of the Sichuan Basin in China from June 2014 to June 2019.We conducted three levels of N addition,including an N control(CK,ambient N input),low N(LN,50 kg·hm^(-2)·a^(-1))and high N(HN,150 kg·hm^(-2)·a^(-1)),and three levels of litterfall manipulation,including intact litter input(L0,no litter alteration),litter reduction(L-,reduced by 50%)and litter addition(L+,increased by 50%).Important findings We found six-year N addition did not significantly alter the aboveground litter input in the studied forest ecosystem.N addition significantly inhibited leaf litter decomposition,with the leaf litter decomposition significantly decreased in high N treatment.N addition significantly reduced the remaining rate of manganese(Mn)in the late stage and promoted the release of Mn.Litter manipulation did not significantly alter the rate of leaf litter decomposition,but increased the remaining rate of Mn in the litter and slowed down the release of Mn.There was no significant interactive effect between N addition and litter manipulation.This study showed that N addition affected litter decomposition in subtropical N-saturated evergreen broadleaf forests by directly affecting litter decomposition,while litter manipulation mainly affected the content of Mn during litter decomposition.Therefore,the content of Mn of litter may play a key role in the process of litter decomposition in response to N input.
作者
仲琦
李曾燕
马炜
况雨潇
邱岭军
黎蕴洁
涂利华
ZHONG Qi;LI Zeng-Yan;MA Wei;KUANG Yu-Xiao;QIU Ling-Jun;LI Yun-Jie;TU Li-Hua(National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River,College of Forestry,Sichuan Agricultural University,Chengdu 611130,China;College of Ecological and Environmental Sciences,East China Normal University,Shanghai 200241,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2023年第5期629-643,共15页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(32071591)。
关键词
氮沉降
凋落物处理
凋落叶分解
养分残留率
亚热带常绿阔叶林
nitrogen deposition
litter manipulation
leaf litter decomposition
remaining of nutrient
subtropical evergreen broadleaf forest