摘要
IPCC 2014综合报告指出亚热带地区降雨将会减少,这会对亚热带地区森林土壤微生物和酶活性产生怎样的影响引起极大关注。以福建省三明市格氏栲自然保护区内200年生米槠天然林为研究对象,于2012年在实验样地布设原位隔离降雨实验,共设置隔离30%降雨、隔离60%降雨和对照3种处理。2017年4月对不同处理进行土壤采样,研究了土壤微生物生物量和酶活性对隔离降雨的响应。结果表明:隔离降雨(30%和60%)显著降低了0~10 cm土层的土壤有机碳(SOC)、可溶性有机碳(DOC)、可溶性有机氮(DON)、总氮(TN)和土壤水分含量(SWC);但对10~20 cm土层影响较小。隔离30%降雨处理0~10 cm土层土壤微生物生物量碳(MBC)和微生物生物量氮(MBN)含量分别比隔离60%降雨处理增加了20.73%和15.71%;10~20 cm土层土壤中各处理之间MBC含量及MBN含量均无显著差异(P<0.05)。冗余分析(RDA)表明:TN和MBC是促使0~10 cm土层酶活性发生变异的主要因素,其解释度分别为43%和16.5%;10~20 cm土层土壤酶活性变异的主要因素是MBC,其解释度是58.1%。2个隔离降雨处理均增加0~10 cm土层土壤多酚氧化酶(PHO)、过氧化物酶(PEO)和β-N-乙酰氨基葡萄糖苷酶(NAG)酶活性,却降低了10~20 cm层土壤多酚氧化酶(PHO)和酸性磷酸酶(ACP)的酶活性。
Changes in frequency and intensity of drought events are anticipated in many areas of the world. The comprehensive report of United Nations Intergovernmental Panel on Climate Change 2014（IPCC 2014） indicated that the subtropical regions are experiencing severe droughts that may become more common in the future. The effects of this trend on soil microbial biomass and enzyme activities in subtropical forests have received great attention. Therefore,we conducted a throughfall exclusion experiment in a 200-year-old Castanopsis carlesii nature forest in July 2012. There were three treatments,viz. 30% throughfall reduction,60% throughfall reduction,control（no throughfall exclusion）. In April 2017,we collected soil sample from each plot to detect the physical and chemical properties,microbial biomass,and enzyme activities. Our results showed that throughfall manipulation significantly decreased the contents of soil organic carbon（SOC）,dissolved organic carbon（DOC）,dissolved organic nitrogen（DON）,total nitrogen（TN） and soil moisture content（SWC） of the surface（0 ～ 10 cm） soil. However,throughfall manipulation had little impact on subsurface（10 ～ 20 cm） soil. In the surface soil,compared with 60% throughfall reduction treatment the content of microbial biomass C and N in the 30% throughfall reduction treatment increased by 20. 73% and 15. 71%,respectively.Nevertheless,in subsurface soil there was no significant difference in microbial biomass between treatments（P 0. 05）. The result of redundant analysis（RDA） indicated that： the total nitrogen（TN）and microbial biomass carbon（MBC） were the main factors that caused the variation of the activity of soil enzyme in the surface soil,with the explanation of 43% and 16. 5%,respectively. The MBC was main factor of soil enzyme activity variation of 10 ～ 20 cm soil,and its interpretation was 58. 1%.Throughfall manipulation increased enzyme activities of phenol oxidase（PHO）,peroxidase（PEO）and β-N-acetylglucosaminidase（NAG） in the surface soil,but decreased the enzyme activities of phenol oxidase（PHO） and acid phosphatase（ACP） significantly.
作者
李帅军
郭剑芬
吴东梅
刘小飞
林伟盛
鲍勇
LI Shuaijun1＇2, GUO Jianfen1＇2, WU Dongmei1＇2, LIU Xiaofei1＇2, LIN Weisheng1＇2, BAO Yong1＇2(Funded by Ministry- of Science and Technology and Fujian Province , Fujian Normal University, Fuzhou 350007, China; 2. School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China)
出处
《亚热带资源与环境学报》
2018年第1期17-25,共9页
Journal of Subtropical Resources and Environment
基金
国家重大科学研究计划资助(2014CB954003)
关键词
米槠天然林
隔离降雨
土壤微生物
酶活性
natural Castanopsis carlesii forest
throughfall exclusion
soil microbial biomass
soilenzyme activity
