干旱区研究 ›› 2020, Vol. 37 ›› Issue (2): 382-389.

• 水土环境 • 上一篇    下一篇

氮添加对天山高寒草原土壤酶活性和酶化学计量特征的影响

勒佳佳1,2,苏原1,2,彭庆文1,2,耿凤展1,2,韩文轩1,3,李文利4,李凯辉1,5,刘学军1,3   

  1. (1. 中国科学院新疆生态与地理研究所干旱区生物地理与生物资源重点实验室, 乌鲁木齐830011;2. 中国科学院大学,北京100049; 3. 中国农业大学资源与环境学院,北京100193;4. 新疆巴音郭楞蒙古自治州草原工作站,库尔勒841000;5. 中国科学院巴音布鲁克草原生态系统研究站,巴音布鲁克841314)
  • 收稿日期:2019-04-28 修回日期:2019-06-12 出版日期:2020-03-26 发布日期:2020-04-21
  • 通讯作者: 李凯辉.E-mail:likh@ms.xjb.ac.cn;刘学军.E-mail:liu310@cau.edu.cn
  • 作者简介:勒佳佳(1993-),女,硕士研究生,研究方向为草原生态学.E-mail:lejiajia1006983797@163.com
  • 基金资助:
    新疆维吾尔自治区自然科学基金项目(2016D01A076)和国家自然科学基金面上项目(41673079)资助

Effects of nitrogen addition on soil enzyme activities and ecoenzymatic stoichiometry in alpine grassland of the Tianshan Mountains

LE Jiajia1,2,SU Yuan1,2,PENG Qingwen1,2,GENG Fengzhan1,2, HAN Wenxuan1,3,LI Wenli4,LI Kaihui1,5,LIU Xuejun1,3   

  1. (1. Key Laboratory of Biogeography and Bioresource in Arid Land,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;2. University of the Chinese Academy of Sciences,Beijing 100039,China;3. College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,China4. Grassland Station of Bayingol mongolian autonomous prefecture of Xinjiang,Korla 841000,Xinjiang,China; 5. Bayinbuluk Grassland Ecosystem Research Station,Chinese Academy of Sciences,Bayinbuluk 841314,Xinjiang,China)
  • Received:2019-04-28 Revised:2019-06-12 Online:2020-03-26 Published:2020-04-21

摘要: 为探究氮添加对高寒草原生态系统土壤酶活性的影响,于2018年在中国科学院巴音布鲁克草原生态系统研究站,选择4个氮添加水平(对照,N0,0 kg·hm-2·a-1;低氮,N1,10 kg·hm-2·a-1;中氮,N3,30 kg·hm-2·a-1;高氮,N9,90 kg·hm-2·a-1),开展土壤酶活性对氮添加响应的研究,分析土壤酶活性对氮添加的响应特点,土壤酶化学计量比以及土壤酶活性与土壤环境因子的关系。结果表明:与对照相比,氮添加在N3水平显著增加β-1,4葡萄糖苷酶(βG)、β-D-纤维二糖水解酶(CBH)和β-1,4木糖苷酶(βX)酶活性(P < 0.05),N1和N3水平显著增加碱性磷酸酶(AKP)活性(P  < 0.05),N3水平显著降低多酚氧化酶(PPO)活性(P  < 0.05),氮添加对亮氨酸氨基肽酶(LAP)活性影响不显著,N3水平下显著增加N-乙酰-β-D氨基葡萄糖苷酶(NAG)活性(P  < 0.05)。相关分析表明,8种土壤酶活性均与土壤有机碳(SOC、NAG除外)和总磷(TP)显著相关,与土壤总氮(TN)不相关。研究区土壤酶活性C∶N∶P化学计量比为1∶1∶1.2,与全球生态系统的土壤酶活性C∶N∶P的比值1∶1∶1相偏离,表明该研究区土壤微生物生长受磷素限制。冗余分析(RDA)进一步揭示出土壤有机碳和土壤全磷含量是影响土壤酶活性的主要因子。

关键词: 氮添加, 土壤酶活性, 土壤酶化学计量, 养分限制, 高寒草原, 巴音布鲁克

Abstract: The effects of nitrogen (N) addition on activities of soil carbon (C),N,and phosphorus (P) circulationrelated enzymes were investigated in an alpine grassland ecosystem in 2018.A longterm simulated N addition experiment was initiated at the Bayinbuluk Grassland Ecological Research Station of the Chinese Academy of Sciences in 2009;four N fertilizer treatments were applied at different sites:control (N0,0 kg·hm-2·a-1),low nitrogen (N1,10 kg·hm-2·a-1),moderate nitrogen (N3,30 kg·hm-2·a-1),and high nitrogen (N9,90 kg·hm-2·a-1).In the present study,stoichiometric ratios of soil ecological enzymes and the relationships between soil enzyme activities and environmental factors were analyzed.Our results revealed the following.Compared with N0,N3 treatment significantly increased β-1,4-glucosidase (BG),cellobiohydrolase (CBH) and β-1,4-xylosidase activities (βx) (P<0.05).N1 and N3 treatments obviously increased phenol oxidase (PPO) activity ( P < 0.05).N3 treatment obviously increased β-1,4-Nacetylglucosaminidase (NAG) activity ( P <0.05).No N treatment affected Lleucine aminopeptidase activity (LAP).Correlation analysis showed that activities of all soil enzymes were positively correlated to soil organic C (SOC) content (except NAG) and total phosphorus (TP) content but were not to total nitrogen content.Soil ecoenzymatic C∶N∶P stoichiometry in the study area was 1∶1∶1.2,which is inconsistent with the global 1∶1∶1 pattern.This result suggests that soil microbial growth in the studied grasslands is limited by P content.Canonical redundancy analysis indicated that SOC and TP were the dominant factors affecting soil enzyme activity.

Key words: nitrogen addition, soil enzyme activity, soil ecoenzymatic stoichiometry, nutrient limitation, alpine grassland, Bayinbuluk