模拟增温下凋落物对大青山油松人工林土壤温室气体通量的影响  

Effects of Litter on Soil Greenhouse Gas Flux of Pinus tabulaeformis Plantation in Daqing Mountain under Simulated Warming

作　　者：梁蕾 马秀枝[1] 韩晓荣 李长生 张志杰 LIANG Lei;MA Xiuzhi;HAN Xiaorong;LI Changsheng;ZHANG Zhijie(Inner Mongolia Agricultural University,Hohhot 010019,P.R.China;Hohhot Meteorological Bureau,Hohhot 010040,P.R.China)

机构地区：[1]内蒙古农业大学,内蒙古呼和浩特010019 [2]呼和浩特市气象局,内蒙古呼和浩特010040

出　　处：《生态环境学报》2022年第3期478-486,共9页Ecology and Environmental Sciences

基　　金：内蒙古自治区自然科学基金项目(2020MS03003)。

摘　　要：大气温度的升高及凋落物的分解通过影响土壤微生物的活动,从而影响土壤呼吸。采用开顶箱式增温(Open Top Chamber,OTC),结合静态箱-气相色谱法,于2020年生长季(5—10月)野外原位观测内蒙古大青山油松(Pinus tabuliformis Carr.)人工林土壤呼吸。试验设置对照(CK)、模拟增温(W)、去除凋落物(NL)、模拟增温+凋落物去除(WNL)4个处理4次重复,同时测定了大气温湿度、土壤温湿度及土壤理化性质。结果表明,(1)增温处理1年后,大气温度、土壤5、10和20 cm处的温度分别较对照增加了1.21、0.50、0.43和0.57℃;土壤5、10和20 cm的含水量分别较对照降低了5.4%、7.1%和6.4%。(2)大青山油松人工林土壤CO_(2)通量变化范围为224.19—601.15 mg·m^(−2)·h^(−1);CH_(4)通量范围为−28.45—−90.2μg·m^(−2)·h^(−1);N_(2)O通量范围为3.94—10.78μg·m^(−2)·h^(−1)。整个生长季4种处理下土壤均表现为CO_(2)、N_(2)O的排放源、CH_(4)的吸收汇。(3)对照和模拟增温处理下土壤CO_(2)通量与大气温度和土壤温度(0—5、5—10、10—20 cm)呈极显著正相关(P<0.01),与土壤TN(0—10 cm)呈极显著负相关(P<0.01),与土壤TN(10—20 cm)呈显著负相关(P<0.05);土壤CH4通量仅在W处理下与大气湿度呈显著负相关(P<0.05);土壤N_(2)O通量在W处理下与土壤TN(0—10、10—20 cm)呈显著负相关(P<0.05)。由此可见,气候变化及地表凋落物层是影响森林土壤呼吸的重要因素;基于100 a时间尺度计算温室气体全球综合增温潜势,模拟增温和凋落物处理下土壤温室气体的排放对气候变暖具有正反馈作用。The increase of atmospheric temperature and litter decomposition affects soil respiration by affecting the activities of soil microorganisms.Open top chamber(OTC)and static chamber gas chromatography were used to observe soil respiration of a Pinus tabulaeformis plantation in Daqing Mountain of Inner Mongolia during the growing season in 2020(May‒October).Four treatments,CK,W,NL and WNL,were set up in the experiment.The temperature and humidity,soil temperature and humidity,and soil physical and chemical properties were measured simultaneously.The results showed that(1)the air temperature and soil temperature at 5 cm and 10 cm increased by 1.21℃,0.50℃,0.43℃and 0.57℃,respectively;The soil moisture of 5 cm,10 cm and 20 cm decreased by 5.4%,7.1%and 6.4%,respectively.(2)The CO_(2) flux ranges between 224.19‒601.15 mg·m^(−2)·h^(−1) in Daqing Mountain;The CH_(4) flux ranges from^(−2)8.45 to−90.2μg·m^(−2)·h^(−1);The N_(2)O flux ranges between 3.94‒10.78μg·m^(−2)·h^(−1).During the whole growing season,the soil CO_(2) fluxes of the four treatments were the emission sources of CO_(2) and N_(2)O,and the absorption sink of CH_(4).(3)Soil CO_(2) flux was significantly positively correlated with air temperature and soil temperature(0‒5,5‒10,10‒20 cm)(P<0.01),negatively correlated with soil TN(0‒10 cm)(P<0.01),and negatively correlated with soil TN(10‒20 cm)(P<0.05);Soil CH_(4) flux was negatively correlated with atmospheric humidity only under the W treatment(P<0.05);Soil N_(2)O flux was negatively correlated with soil TN(0‒10,10‒20 cm)under the w treatment(P<0.05).Therefore,climate change and surface litter layer are important factors affecting forest soil respiration.Based on a100-yeartime scale,the global warming potential for greenhouse gases was calculated to simulate the soil greenhouse gas emission under warming and litter removal treatments,which showed positive effects on climate warming.

关 键 词：模拟增温 土壤呼吸 温室气体通量 凋落物 油松人工林 

分 类 号：S718.5[农业科学—林学] X16[环境科学与工程—环境科学]