摘要
植物残体是引起土壤、微生物和胞外酶C∶N∶P改变的关键因素,但是其作用机理尚不明确。本研究以青藏高原东缘高寒草甸为对象,通过测定土壤、微生物生物量和胞外酶活性等指标,探究移除地上植物或根系及植物残体添加对土壤、微生物和胞外酶C∶N∶P的影响。结果表明:与无人为扰动草甸相比,移除地上植物显著降低了土壤C∶N(变幅为-23.7%,下同)、C∶P(-14.7%)、微生物生物生物量C∶P、N∶P,显著提高了微生物生物量C∶N、胞外酶C∶N∶P。与移除地上植物相比,移除地上植物和根系显著降低了土壤C∶N(-11.6%)、C∶P(-24.0%)、N∶P(-23.3%)和微生物生物量C∶N,显著提高了微生物生物量N∶P和胞外酶N∶P;移除地上植物后添加植物残体显著提高了微生物生物量C∶N、C∶P和胞外酶C∶N,显著降低了胞外酶N∶P。与移除地上植物和根系相比,移除地上植物和根系后添加植物残体显著降低了土壤C∶N(-16.4%)、微生物生物量C∶P、N∶P和胞外酶N∶P,显著提高了胞外酶C∶N。综上可知,去除植物显著影响土壤、微生物和胞外酶的C∶N∶P,微生物生物量和胞外酶C∶N∶P对植物残体的响应更为敏感。有无根系是添加植物残体时土壤、微生物和胞外酶的生态化学计量稳定性强弱的关键所在。添加植物残体的措施适用于植物根系尚且完好的草甸,有利于高寒草甸土壤碳固存,对没有根系的草甸土壤可能不适用,会增加土壤CO_(2)排放。
Plant residues can affect C:N:P of soil,microbial biomass,and extracellular enzyme,but the effects are still unclear.We conducted a field experiment in an alpine meadow on the eastern part of the Qinghai-Tibetan Plateau to explore the effects of removing aboveground plant or roots and adding plant residues on the C:N:P of soil,microbial biomass,and extracellular enzyme.The results showed that removing aboveground plant biomass significantly decreased soil C:N(the change was-23.7%,the same below)and C:P(-14.7%),microbial biomass C:P and N:P,while significantly increased microbial biomass C:N,and enzyme C:N:P compared with meadow without human disturbance.Removing all plant biomass(aboveground and roots)significantly reduced soil C:N(-11.6%),C:P(-24.0%),N:P(-23.3%)and microbial biomass C:N in comparison to removing aboveground plant,while significantly improved microbial biomass N:P and enzyme N:P.Adding plant residues after removing aboveground plant significantly increased microbial biomass C:N and C:P,enzyme C:N compared with removing aboveground plant,while significantly decreased enzyme N:P.Compared with removing all the plant,adding plant residues after removing whole plant significantly reduced soil C:N(-16.4%),microbial biomass C:P,N:P and enzyme N:P,while significantly increased enzyme C:N.Our results suggest that removal of plants could have a strong effect on C:N:P of soil,microbial biomass,and extracellular enzyme,and C:N:P of microbial biomass and that extracellular enzyme woule be more sensitive to plant residues.Roots could play a key role in stabilizing C:N:P of soil,microbial biomass,and extracellular enzyme under plant residues addition.Adding plant residues could be a suitable solution for restoring alpine meadows under the circumstance of intact roots,which was conducive to soil C storage,but might not be suitable for alpine meadows with serious root damage,which would increase soil CO_(2) emission.
作者
肖向前
张海阔
冯娅斯
王吉鹏
梁辰飞
陈有超
朱高荻
蔡延江
XIAO Xiang-qian;ZHANG Hai-kuo;FENG Ya-si;WANG Ji-peng;LIANG Chen-fei;CHEN You-chao;ZHU Gao-di;CAI Yan-jiang(State Key Laboratory of Subtropi-cal Silviculture,Zhejiang A&F University/College of Environmental and Resource Sciences,Zhejiang A&F University,Hangzhou 311300,China;College of Ecology and Environment,Chengdu University of Technology,Chengdu 610059,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2023年第1期58-66,共9页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41877085,41573070)资助。
关键词
凋落物
高寒草地
微生物生物量
土壤胞外酶
化学计量比
litter
alpine grassland
microbial biomass
soil extracellular enzyme
stoichiometric ratio
