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应用生态学报 ›› 2022, Vol. 33 ›› Issue (7): 1791-1800.doi: 10.13287/j.1001-9332.202207.029

• 生物土壤结皮专栏 • 上一篇    下一篇

亚热带苔藓结皮对土壤-微生物-胞外酶化学计量特征的影响

张冠华1,2*, 易亮3, 孙宝洋1,2, 李建明1,2, 沈盛彧1,2   

  1. 1长江科学院水土保持研究所, 武汉 430010;
    2水利部山洪地质灾害防治工程技术研究中心, 武汉 430010;
    3中南安全环境技术研究院股份有限公司, 武汉 430071
  • 收稿日期:2022-04-29 接受日期:2022-06-09 出版日期:2022-07-15 发布日期:2023-01-15
  • 通讯作者: *E-mail: zgh83113@126.com
  • 作者简介:张冠华, 女, 1983年生, 博士, 高级工程师。主要从事土壤侵蚀与水土保持研究。E-mail: zgh83113@126.com
  • 基金资助:
    国家自然科学基金项目(41877082,42107352)和中央级公益性科研院所基本科研业务费专项资金(CKSF2021487/TB,CKSF2021447/TB)资助。

Effects of moss biocrusts on soil-microbe-ectoenzyme stoichiometric characteristics in a subtropical area

ZHANG Guan-hua1,2*, YI Liang3, SUN Bao-yang1,2, LI Jian-ming1,2, SHEN Sheng-yu1,2   

  1. 1Soil and Water Conservation Department, Changjiang River Scientific Research Institute, Wuhan 430010, China;
    2Research Center on Mountain Torrent & Geologic Disaster Prevention, Ministry of Water Resources, Wuhan 430010, China;
    3Central-Southern Safety & Environment Technology Institute Co. Ltd., Wuhan 430071, China
  • Received:2022-04-29 Accepted:2022-06-09 Online:2022-07-15 Published:2023-01-15

摘要: 生物结皮的形成和发育显著影响土壤碳(C)、氮(N)、磷(P)循环及其化学计量特征,土壤微生物如何适应环境资源的化学计量变化仍不明确。本研究以三峡库区苔藓结皮为对象,分析结皮盖度(0、1%~20%、20%~40%、40%~60%、60%~80%和80%~100%)对土壤理化性质(0~5和5~10 cm土层)、微生物生物量和胞外酶活性[(β-1,4-葡萄糖苷酶(BG)、β-1,4-N-乙酰氨基葡萄糖苷酶(NAG)、酸性磷酸酶(AP)]的影响,探索土壤-微生物-胞外酶C∶N∶P化学计量特征间的协变性。结果表明: 生物结皮发育显著提高了土壤黏粒、水稳性团聚体和土壤C、N、P含量,显著降低了土壤容重和砂粒含量;微生物生物量C、N、P和胞外酶活性均随结皮盖度的增大而显著增加;土层深度对土壤理化性质及C∶N∶P均无显著影响,但显著影响微生物生物量、胞外酶活性及BG∶AP和NAG∶AP。相关分析显示,土壤C、N、P含量与微生物生物量和胞外酶活性呈显著正相关,与BG∶NAG呈显著负相关,与NAG∶AP呈显著正相关,但与微生物生物量C∶N∶P无显著相关性;土壤-微生物、微生物-胞外酶C∶N∶P相关性均不显著,BG∶NAG∶AP随着微生物与土壤间C∶N∶P化学计量不平衡性的增加而逐渐降低。表明微生物养分代谢同时受N和P的限制,且P的限制较强烈,微生物可以通过调整自身生物量以及胞外酶C∶N∶P适应生物结皮发育驱动的土壤化学计量变化,从而维持内稳态。

关键词: 生物结皮, 阈值元素比, 化学计量内稳性, 养分限制

Abstract: The formation and development of biological soil crusts (biocrusts) potentially affect the cycles and stoichiometric characteristics of soil carbon (C), nitrogen (N), and phosphorus (P). However, it is still unclear how soil microbes adapt to such changes. In this study, we examined the effects of moss-dominated biocrusts coverage (0, 1%-20%, 20%-40%, 40%-60%, 60%-80%, and 80%-100%) on soil physicochemical properties, soil microbial biomass, and ectoenzyme activities [β-1, 4-glucosidase (BG), β-1, 4-N-acetyl glucosidase (NAG), acid phosphatase (AP)] in two soil layers (0-5 and 5-10 cm) in the Three Gorges Reservoir area, as well as the covariations of soil-microbe-ectoenzyme C:N:P stoichiometry. The results showed that biocrust development significantly increased soil clay content, water stable aggregates, soil C, N, P contents, and significantly decreased soil bulk density and sand content. Microbial biomass C, N, P and ectoenzyme activities were significantly increased with increasing biocrust coverage. Soil depth did not affect soil physicochemical properties and C:N:P, but significantly affected microbial biomass, ectoenzyme activities, BG:AP and NAG:AP. Soil C, N and P contents were significantly positively correlated with microbial biomass and ectoenzyme activities, negatively correlated with BG:NAG, while positively correlated with NAG:AP, but had no significant correlation with microbial biomass C:N:P. There was no significant correlation between soil-microbe and microbial-ectoenzyme C:N:P. BG:NAG:AP decreased gradually with the increase of C:N:P stoichiometric imbalance between microbe and soil. This study indicated that the microbial metabolism was co-limited by N and P and with stronger P limitation. Microbes could maintain homeostasis by adjusting their own biomass and ectoenzyme C:N:P to adapt to changes in soil ecological stoichiometry driven by biocrust development.

Key words: biological soil crusts, threshold elemental ratio, stoichiometric homeostasis, nutrient limitation