氮沉降下滇中华山松林土壤特性变化对土壤呼吸的影响  

Effects of Nitrogen Deposition on Soil Respiration Based on the Changes in Soil Properties of Pinus armandii Forest in Yunnan Province

作　　者：梁阳森 王克勤[1,2] 宋娅丽 郑兴蕊[1] 胡淳 LIANG Yang-sen;WANG Ke-qin;SONG Ya-li;ZHENG Xing-rui;HU Chun(College of Ecology and Environment,Southwest Forestry University,Kunming 650224,Yunnan,China;Yuxi Forestry Ecosystem Research Station of National Forestry and Grassland Administration,Kunming 650224,Yunnan,China;Yunnan Economics Trade and Foreign Affairs College,Kunming 650224,Yunnan,China)

机构地区：[1]西南林业大学生态与环境学院,云南昆明650224 [2]国家林业和草原局云南玉溪森林生态系统国家定位观测研究站,云南昆明650224 [3]云南经贸外事职业学院,云南昆明650224

出　　处：《西北林学院学报》2023年第6期10-19,共10页Journal of Northwest Forestry University

基　　金：云南省教育厅科学研究基金项目(2021Y236);云南省农业基础研究联合专项(202301BD070001-059);云南省一流学科:水土保持与荒漠化防治学(05000-523005);云南省自然生态监测网络项目云南玉溪森林生态站运行(2022-YN-13);云南玉溪森林生态系统国家长期科研基地(2020132550)。

摘　　要：研究氮(N)沉降背景下湿、干季土壤理化性质、微生物特征及酶活性变化对土壤呼吸影响,阐明N沉降下土壤呼吸的季节变化特征以及土壤呼吸与土壤特性之间的动态响应,为滇中亚高山森林生态系统C循环研究提供科学依据。选择云南玉溪磨盘山华山松人工林为研究对象,研究模拟N沉降下(对照-CK,0 g·m^(-2)·a^(-1)、低N-LN,10 g·m^(-2)·a^(-1)、中N-MN,20 g·m^(-2)·a^(-1)、高N-HN,25 g·m^(-2)·a^(-1))湿(7月)、干(1月)季土壤理化性质、酶活性、土壤微生物数量、微生物量C(MBC)、微生物量N(MBN)以及土壤呼吸变化特征,阐明N沉降下土壤呼吸与土壤特性的动态变化特征。结果表明,1)湿季时,与CK相比,各N沉降处理下土壤TP、TK、NH_(4)^(+)-N、NO_(3)^(-)-N、AN均显著增加(13.1%~95.5%);干季时,TN、TP、NH_(4)^(+)-N、AN显著增加(26.9%~69.6%)。2)在湿干两季过氧化氢酶活性均在各N处理下显著降低(14.8%~61.8%),多酚氧化酶活性则在湿季各N处理下降低(15.0%~52.2%),蔗糖酶及脲酶活性在不同季节分别在LN、HN处理以及HN处理下显著降低(7.1%~48.9%和10.5%~16.7%);在湿干季时,HN处理降低了土壤微生物数量、MBC、MBN(10.3%~49.8%)。3)N沉降抑制了华山松林土壤呼吸,且随着施N浓度的增加,土壤呼吸抑制作用越明显;土壤呼吸与湿干季土壤温度呈正显著相关;各N处理均降低了土壤温度敏感性Q_(10)(2.93%~36.86%)。综上,N沉降抑制了华山松林的土壤呼吸,且并未改变华山松林土壤呼吸的季节变化规律与日变化规律。This study investigated the effects of soil physical and chemical properties,microbial characteristics and enzyme activities on soil respiration in wet and dry seasons under the background of nitrogen(N)deposition,and elucidated the seasonal changes of soil respiration under N deposition and the dynamic response between soil respiration and soil properties,so as to provide a scientific basis for the study of carbon(C)cycle in alpine forest ecosystems in Central Yunnan.The soil physicochemical properties,enzyme activity,soil microbial population,and microbial carbon(MBC)were studied under simulated N deposition(control-CK,0,low-LN,10,medium-MN,20,and high-HN,25 g·m^(-2)·a^(-1))in wet(July)and dry(January)seasons in a Pinus armandii plantations in Yuxi,Yunnan.The results showed that 1)soil TP,TK,NH_(4)^(+)-N,NO_(3)^(-)-N,and AN increased significantly(13.1%-95.5%)under each N deposition treatment compared with CK in the wet season,and TN,TP,NH_(4)^(+)-N,and AN increased significantly(26.9%-69.6%)in the dry season.2)Catalase activity significantly decreased in both wet and dry seasons under each N treatment(14.8%-61.8%),while polyphenol oxidase activity decreased in the wet season under each N treatment(15.0%-52.2%),and sucrase and urease activities significantly decreased in different seasons under LN,HN,and HN treatment,respectively(7.1%-48.9%and 10.5%-16.7%);HN treatment reduced soil microbial population,MBC,and MBN during the wet and dry seasons(10.3%-49.8%).3)N deposition inhibited soil respiration in P.armandii forest,and the inhibition of soil respiration became more pronounced with the increase of applying N concentration;soil respiration was positively and significantly correlated with soil temperature in the wet-dry season;all N treatments reduced soil temperature sensitivity Q_(10)(2.93%-36.86%).In conclusion,N deposition inhibits soil respiration in P.armandii forest,and dose not change the seasonal and daily patterns of soil respiration.

关 键 词：N沉降 华山松林 土壤呼吸 森林土壤特性 

分 类 号：S791.241[农业科学—林木遗传育种]