密度调控对女贞人工林土壤N_2O排放的影响  

Effect of density-dependent regulation on N_2O emission in Ligustrum lucidum plantation

作　　者：卢雯[1] 丁辉[1] 邱雷[1] 关庆伟[1] 

机构地区：[1]南京林业大学森林资源与环境学院,南京210037

出　　处：《安徽农业大学学报》2015年第2期186-191,共6页Journal of Anhui Agricultural University

基　　金："十二五"国家科技支撑项目(2011BAD38B03-2);江苏高校优势学科建设工程项目(PAPD)共同资助

摘　　要：以江苏省扬州市江都区女贞人工林为对象,研究了密度调控对其土壤N2O排放通量的影响。结果表明,3种密度下土壤N2O排放通量均是秋季和春季较高,冬季最低。秋季时,3种密度下N2O排放通量大小比较为4225株·hm-2(9.985μg m-2·h-1)>1050株·hm-2(8.195μg·m-2·h-1)>2275株·hm-2(6.971μg·m-2·h-1),但各密度间差异不显著(P>0.05)。冬季时,N2O排放通量下降明显,其中4225株·hm-2密度(-10.355μg·m-2·h-1)和2275株·hm-2密度(-2.716μg·m-2·h-1)均为负值,且两者明显低于1050株·hm-2密度下N2O排放通量(2.629μg·m-2·h-1)。春季伴随着温度的回升,各密度下N2O排放通量均显著增加,并达到4个季度中的最高值,其中2275株·hm-2密度下排放通量最低(7.513μg·m-2·h-1),且与4225株·hm-2(11.839μg·m-2·h-1)和1050株·hm-2(12.175μg·m-2·h-1)密度间差异达到极显著水平(P<0.01)。夏季时,3种密度下N2O排放通量分别为4225株·hm-2(3.201μg·m-2·h-1),2275株·hm-2(7.658μg·m-2·h-1)和1050株·hm-2(6.804μg·m-2·h-1),各密度间差异并不显著(P>0.05)。土壤N2O排放通量与土温呈极显著正相关(P<0.01),与NH4+-N和NO3--N含量间则呈极显著负相关(P<0.01)。土壤氮矿化速率与N2O排放通量也呈线性相关极显著(P<0.01),说明密度调控作用于土壤因子,并对N2O排放产生明显影响。The effect of density-dependent regulation on soil N20 flux in Ligustrum lucidum plantation in Ji- angdu district of Yangzhou was studied. The resuks showed that the fluxes under the three densities had high values in autumn and spring and low values in winter. In autumn, the average of N20 flux showed： 4225 tree/hm2 （9.985 μg.m-2.h-1）〉 1050 tree/lam2（8.195 μg.m-2.h-1）〉2275 tree/hm2 （6.971 μg.m2.hl）. In winter, the N20 flux significantly decreased in which both 4225 tree/hm2 （-10.355 μg.m-2.h-1） and 2275 tree/bin2 （-2.716 μg.m-2.h-1） were significantly lower than 1050 tree/hm2 （2.629 μg.m2-h-1）. The N20 flux in the plot with a density of 2275 tree/hmz （7.513 txg,m.2.h-1） was lower than that in other two plots and the difference was highly significant （P〈0.01）. In summer, the N2O fluxes in three plantation densities were as follows： 4225 tree/hm2, 3.201μg.m-2.h-1; 2275 tree/hm2, 7.658 μg.m-2.h-1; and 1050 tree/bin2, 6.804 μg.m2.h-1. The N20 flux had a significant positive relationship with soil tem- perature （P〈0.01）, while it had an extremely negative correlation with NH4＋-N and NO3-N content （P〈0.01）. A highly significant correlation between N2O flux and soil nitrogen mineralization （P〈0.01） was also observed. It is suggested that density-dependent regulation would affect soil factors and have significant influence on N2O emission.

关 键 词：密度调控 女贞人工林 N2O排放 土壤因子 

分 类 号：S718.5[农业科学—林学]