植物生态学报 ›› 2022, Vol. 46 ›› Issue (7): 834-845.DOI: 10.17521/cjpe.2021.0430

所属专题: 生态化学计量

• 研究论文 • 上一篇    下一篇

黔西南石漠化过程中土壤胞外酶活性及其化学计量变化特征

孙彩丽1,2,*(), 仇模升1, 黄朝相1, 王艺伟1   

  1. 1贵州民族大学生态环境工程学院, 贵阳 550025
    2贵州民族大学喀斯特环境地质灾害防治国家民委重点实验室, 贵阳 550025
  • 收稿日期:2021-11-23 接受日期:2022-01-08 出版日期:2022-07-20 发布日期:2022-07-15
  • 通讯作者: 孙彩丽
  • 作者简介:* E-mail: suncaili2007@126.com
  • 基金资助:
    贵州省科技计划项目(黔科合基础[2020]1Y192);国家自然科学基金(41967058);贵州省教育厅青年科技人才成长项目([2018]135)

Characteristics of soil extracellular enzyme activities and their stoichiometry during rocky desertification in southwestern Guizhou, China

SUN Cai-Li1,2,*(), QIU Mo-Sheng1, HUANG Chao-Xiang1, WANG Yi-Wei1   

  1. 1College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China
    2The Karst Environmental Geological Hazard Prevention of Key Laboratory of State Ethnic Affairs Commission, Guizhou Minzu University, Guiyang 550025, China
  • Received:2021-11-23 Accepted:2022-01-08 Online:2022-07-20 Published:2022-07-15
  • Contact: SUN Cai-Li
  • Supported by:
    Guizhou Provincial Science and Technology Projects ([2020]1Y192);National Natural Science Foundation of China(41967058);Science and Technique Foundation of Education Department of Guizhou Province, China([2018]135)

摘要:

为明确喀斯特石漠化过程中土壤胞外酶活性及其化学计量变化特征以及它们对环境变异的生态响应规律。该研究以5种不同石漠化程度的土壤生态系统为研究对象, 运用生态化学计量学理论与方法, 系统研究石漠化对6种胞外酶(β-1,4-葡糖苷酶(BG)、β-1,4-木糖苷酶(BX)和纤维素二糖水解酶、β-1,4-乙酰-葡糖胺糖苷酶、亮氨酸氨基肽酶(LAP)和酸性磷酸酶(AP))活性及其化学计量的影响, 并分析它们与环境因子之间的相关性。结果表明: 无石漠化、潜在和轻度石漠化阶段BG、BX、LAP和AP胞外酶活性显著高于中度和重度石漠化阶段, 但不同石漠化阶段土壤胞外酶化学计量特征差异不显著。不同石漠化程度土壤质量大体分为3类, 其中, 无石漠化土壤生化性状最优, 潜在和轻度石漠化土壤次之, 且均优于中度和重度石漠化土壤, 并且, 无石漠化、潜在和轻度石漠化土壤存在缺磷现象(酶矢量角度大于45°), 而中度和重度石漠化土壤氮缺乏(酶矢量角度小于45°)。此外, 石漠化过程中土壤胞外酶活性及其化学计量特征的变化主要受土壤全氮、速效磷、硝态氮、氨态氮和枯落物磷含量的影响, 总体表现为与土壤养分含量具有趋同性并受枯落物磷含量的限制。综上, 石漠化生态系统修复和治理过程中, 需考虑在潜在和轻度石漠化阶段补充磷, 在中度和重度石漠化阶段补充氮, 以缓解相关养分限制。

关键词: 石漠化, 土壤养分, 化学计量, 胞外酶, 喀斯特

Abstract:

Aims In this study, we sought to determine changes in soil extracellular enzyme activities and their stoichiometric characteristics during the process of karst rocky desertification and their ecological response to environmental variation.

Methods Soil ecosystems at five stages of rocky desertification were selected for investigation and we applied the theory and methods of ecological stoichiometry to systematically study the effects of rocky desertification on the activities of six extracellular enzymes (β-1,4-glucosidase, cellobiohydrolase, β-1,4-xylosidase, β-1,4-N- acetylglucosaminidase, leucine aminopeptidase, and acid phosphatase). We also analyzed correlations between enzyme activities and environmental factors.

Important findings The results revealed that the extracellular activities of β-1,4-glucosidase, cellobiohydrolase, β-1,4-xylosidase, and leucine aminopeptidase, in the no, potential, and slight stages of rocky desertification were significantly higher than those in the moderate and severe stages. In contrast, the stoichiometric characteristics of soil extracellular enzymes showed no significant differences among the different stages of rocky desertification. The quality of soil at the different stages of desertification could be roughly divided into three categories, namely, the biochemical properties of non-rocky desertification soil were superior to those at the potential and slight stages, which in turn were superior to those at the moderate and severe stages. In addition, soils at the no, potential, and slight stages of rocky desertification were found to be phosphorus deficient (the enzyme vector angle was greater than 45°), whereas soils at the moderate and severe stages were deficient in nitrogen (the enzyme vector angle was less than 45°). Moreover, we established that during the process of rocky desertification, the changes in soil extracellular enzyme activities and their stoichiometric characteristics were mainly influenced by soil total nitrogen, available phosphorus, nitrate nitrogen, ammonium nitrogen, and litter phosphorus contents. The observed changes in soil extracellular enzyme activities were found to be correlated with changes in nutrient contents, and tended to be limited by litter phosphorus content. On the basis of these findings, as measures to alleviate the associated nutrient limitations, we would recommend supplementation with phosphorus in the potential and slight stages of rocky desertification and the supplementary application of nitrogen in the moderate and severe stages during the restoration of rocky desert ecosystems.

Key words: rocky desertification, soil nutrients, stoichiometry, extracellular enzymes, karst