氮添加对苏北沿海杨树人工林土壤活性有机碳库的影响  

Effects of simulated nitrogen deposition on soil active organic carbon in poplar plantations along Northern Jiangsu coast

作　　者：许凯[1] 徐钰[1] 张梦珊 徐长柏 曹国华[2] 葛之葳[1] 阮宏华[1] 

机构地区：[1]南京林业大学,江苏省林业生态工程重点实验室,南京210037 [2]江苏省东台市国营林场,江苏东台224200

出　　处：《生态学杂志》2014年第6期1480-1486,共7页Chinese Journal of Ecology

基　　金：国家重点基础研究发展计划项目(2012CB416904);江苏省普通高校研究生科研创新计划项目(CXLX12-0521)资助

摘　　要：大气氮沉降成为目前全球性的环境问题之一,氮的沉降可能显著影响森林土壤碳循环过程。从2012年5月起,对东台林场3种林龄(5、9、15年生)黑杨派无性系I-35杨(Populus deltoides CL‘35’)人工林进行野外模拟氮沉降试验,探讨氮沉降对不同林龄杨树人工林土壤活性有机碳的影响。经过1年施氮试验后,5和9年生杨树人工林的土壤微生物生物量碳随着氮沉降水平的增加呈现出先增加后减少的趋势;而15年生林分在不同氮处理下,土壤微生物生物量碳均有所增加;3种林龄在不同氮处理下土壤可溶性有机碳含量随着氮浓度的增加而增加。土壤微生物生物量碳与可溶性有机碳之间以及这二者与土壤全氮、微生物生物量氮、可溶性有机氮、铵态氮、硝态氮之间存在显著相关。试验表明,氮沉降可能增加土壤活性有机碳含量,从而影响杨树人工林土壤碳动态。The impacts of nitrogen deposition on soil labile carbon at different age poplar plantations were examined in this study. Beginning in May 2012,we conducted a field experiment to simulate nitrogen deposition with five treatments at Dongtai Forest Farm in Jiangsu Province. In June 2013,the soil samples were taken to analyze the variations of soil labile organic carbon.The results indicated that soil microbial biomass carbon decreased after an initial increase with the increasing nitrogen level in the 5 and 9 years old poplar plantations,and increased with the increased nitrogen level in the 15 years old poplar plantation. Increasing the level of nitrogen enhanced the content of soil dissolved organic carbon in all poplar plantations. There was a significant correlation between the soil MBC and DOC. Furthermore,the soil MBC and DOC were significantly correlated with the soil TN,MBN,DON,NH4^＋-N,NO3^--N. Our results imply that nitrogen deposition might enhance the content of soil labile organic carbon,and thus affect the dynamics of soil organic carbon in the poplar plantations.

关 键 词：氮沉降 杨树人工林 土壤微生物生物量碳 土壤可溶性有机碳 

分 类 号：S714.5[农业科学—林学]