亚热带常绿阔叶林土壤微生物量动态变化及其对氮磷添加的响应  

Dynamical Pattern of Soil Microbial Biomass and Its Response to Nitrogen and Phosphorus Additions in A Subtropical Evergreen Broad-leaved Forest

作　　者：戴允泽 王会荣[1] 李爱琴 朱永一 汪小鹏 房震 徐小牛[1] DAI Yunze;WANG Huirong;LI Aiqin;ZHU Yongyi;WANG Xiaopeng;FANG Zhen;XU Xiaoniu(School of Forestry&Landscape Architecture,Anhui Agricultural University,Hefei 230036,China;Meteorological Bureau of Qimen County,Huangshan 245600,China;Zhawan Natural Reserve,Qimen County,Huangshan 245609,China)

机构地区：[1]安徽农业大学林学与园林学院,安徽合肥230036 [2]祁门县气象局,安徽黄山245600 [3]祁门县渣湾自然保护区,安徽黄山245609

出　　处：《生态环境学报》2018年第8期1395-1404,共10页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31770672;31370626);国家"973"计划项目(2012CB416905)

摘　　要：土壤微生物是土壤生物化学过程的驱动者,对环境变化极其敏感。为了探讨不同年份气候差异及不同坡位土壤微生物对氮沉降的响应机制,在安徽南部查湾自然保护区选择不同坡位亚热带常绿阔叶林,就氮、磷添加对土壤微生物量碳(MBC)、氮(MBN)的影响进行了为期3年的试验研究。选择中坡和坡顶两种立地类型,分别设置3种控制实验,对照(CK,0 kg N?hm^(-2)?a^(-1))、氮添加(N,100 kg N?hm^(-2)?a^(-1))、氮磷添加(N+P,100 kg N?hm^(-2)?a^(-1)+50 kg P?hm^(-2)?a^(-1))。取样后,测试不同处理土壤MBC、MBN及土壤理化性质。结果表明,氮磷添加后,不同坡位MBC和MBN季节变化存在差异。与対照相比,氮磷和氮添加中坡MBC分别降低了14.6%和15.4%,而在坡顶,两种处理MBC分别提高5.8%和2.1%。中坡MBC变化范围为171.94~2 151.35 mg?kg^(-1),MBN变化范围为52.14~203.3 mg?kg^(-1);坡顶MBC变化范围为102.49~2 219.95 mg?kg^(-1),MBN变化范围为38.56~203.3 mg?kg^(-1)。中坡第2年、第3年及坡顶第3年氮磷和氮添加降低了ω(MBC)/ω(MBN)比,不同坡位ω(MBC)/ω(MBN)比均值为7.88~14.21。土壤微生物量的季节变化显著,土壤MBN在生长季节(5月、7月、9月及11月)较高,最低值出现在休眠期(1月);养分添加改变了土壤MBN季节变化规律。季节、坡位改变了土壤微生物量碳氮和土壤养分的相关性。因此,养分添加对不同立地土壤微生物的影响不同,且不同年份存在差异。长期氮、磷添加降低了ω(MBC)/ω(MBN)比值,但不同坡位反应时间存在差异。土壤MBC、MBN不同年份之间差异显著,主要受不同年份降雨和气温变化控制。冗余分析(RDA)表明,月降水频率、不同年份气温及降水差异、林分因子及土壤理化性质均对土壤微生物量存在显著影响,其季节变化由降水频率(月降水天数)、降水量及气温变化和月降水量及气温波动差异(月标准差)所控制。Soil microbes are the drivers of soil biochemical processes and are extremely sensitive to environmental changes.In order to explore the climate differences in different years and the response mechanisms of soil microorganisms to nitrogen deposition at different slope positions,the subtropical evergreen broad-leaved forests with different slope positions were selected in the Zhawan Nature Reserve in southern Anhui Province,and nitrogen and phosphorus were added to study the effect of the soil microbial biomass carbon(MBC)and nitrogen(MBN)over a three-year period.Two kinds of site types were selected:middle slope and top slope,and three control experiments were set up,control(CK,N 0 kg·hm-2·a-1),nitrogen addition(N,N 100 kg·hm-2·a-1),and nitrogen and phosphorus addition(N+P,N 100 kg·hm-2·a-1+P 50 kg·hm-2·a-1).After sampling,soil MBC,MBN,and soil physical and chemical properties were tested.The results showed that there were differences in soil microbial biomass carbon(MBC)and nitrogen(MBN)between the two slope positions after N+P and N additions.Compared with the control,the MBC on the mid-slope decreased by 14.6%and 15.4%after N+P and N additions,respectively.On the flat ridge,the MBC was increased by 5.8%and 2.1%after N+P and N additions,respectively.The range of MBC varied from 171.94 to 2 151.35 mg?kg-1,and MBN from 52.14 to 203.3 mg?kg-1 on the mid-slope.On the flat ridge,the mean MBC ranged from 102.49 to 2 219.95 mg?kg-1 and MBN from 38.56 to 203.3 mg?kg-1.After N+P and N additions,the mean MBC/MBN ratios were decreased in the 2nd and 3rd years on mid-slope and in the 3rd year on the flat ridge.The mean MBC/MBN ratios ranged from 7.88 to 14.21 for the different slope positions.There existed significant seasonal variation in soil microbial biomass,with relatively high MBN in the growing season(May,July and November)and lowest in the dormant season(January).The N+P and N additions changed the seasonal variation of MBN,while not change of MBC.The relationship between soil microbial biomass and soil nut

关 键 词：氮磷添加 季节变化 不同坡位 土壤微生物量 常绿阔叶林 

分 类 号：S718.5[农业科学—林学]