增温对亚热带杉木人工林土壤氮转化过程的影响  

Effects of warming on soil nitrogen transformations in subtropical Chinese-fir plantations

作　　者：王云 毛超 林伟盛 杨智杰[1,2] 熊德成 胥超[1,2] 刘小飞 陈仕东[1,2] WANG Yun;MAO Chao;LIN Weisheng;YANG Zhijie;XIONG Decheng;XU Chao;LIU Xiaofei;&CHEN Shidong(Fujian Sanming Forest Ecosystem National Observation and Research Station,Sanming 365002,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China)

机构地区：[1]福建三明森林生态系统国家野外科学观测研究站,三明365002 [2]福建师范大学地理科学学院,福州350117

出　　处：《应用与环境生物学报》2024年第3期537-543,共7页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(32201354)资助。

摘　　要：氮素是森林生产力的重要限制因子.气候变暖会改变森林生态系统氮循环过程,进而影响森林生态系统生产力.然而,目前关于森林土壤氮循环如何响应气候变暖的认识仍存在不足,尤其缺乏来自亚热带森林生态系统的证据.为此,依托亚热带杉木林野外增温试验平台,原位监测杉木幼林和成熟林0-20 cm土层土壤净氮矿化速率、净硝化速率、土壤氧化亚氮(N_(2)O)排放速率以及无机氮淋溶量,探究增温对亚热带杉木林土壤氮转化过程的影响.结果表明:林分类型未显著影响土壤原位土壤N_(2)O排放速率和铵态氮淋溶量,但杉木成熟林的土壤净氮矿化速率、净硝化速率显著高于杉木幼林的.与对照相比,增温4℃未显著改变原位土壤净氮矿化速率和净硝化速率,也未显著影响原位土壤N_(2)O排放速率.同时,增温使幼林土壤硝态氮淋溶量显著降低了38.7%,但未显著影响杉木幼林和成熟林土壤铵态氮淋溶量以及成熟林土壤硝态氮淋溶量.总的来说,增温处理未改变原位土壤净氮转化速率、N_(2)O排放速率以及杉木成熟林无机氮淋溶量,说明土壤增温并未增加亚热带森林土壤无机氮净输入量和土壤氮损失量.这一研究促进了我们对气候变暖条件下亚热带森林土壤氮循环的理解.N is an important limiting factor for sustaining forest productivity.Climate warming may influence the soil N transformation and regulate the productivity of forest ecosystems.However,there are still knowledge gaps regarding how forest soil N cycling responds to climate warming,especially due to the lack of experimental evidence from subtropical regions.In this study,based on a soil warming experiment in subtropical Chinese-fir plantations,the rates of net soil N mineralization,net nitrification,nitrous oxide(N_(2)O)emission,and inorganic N leaching at a soil depth of 0–20 cm were observed in situ.The results showed that the rates of soil N_(2)O emissions and ammonium leaching did not differ significantly between the young and mature plantations.Mature plantations had higher net soil N mineralization,nitrification,and leaching rates than young plantations.Soil warming had no significant effect on the soil net N mineralization rate,net nitrification rate,or N_(2)O emission rate.Although the amount of nitrate leached in young plantations was reduced by 38.7%under soil warming,nitrate leached in mature plantations and ammonium leached in both young and mature plantations showed no significant response to soil warming.Overall,soil warming failed to alter the net soil N transformation rates,N_(2)O emission rate,or amount of inorganic N leaching,indicating that the net input and leaching loss of soil inorganic N did not respond positively to soil warming in subtropical forests.This study enhances our understanding of soil N cycles in subtropical forests under climate warming scenarios.

关 键 词：增温 亚热带杉木人工林 矿化 硝化 N2O排放速率 无机氮淋溶 

分 类 号：S791.27[农业科学—林木遗传育种]