Chin J Plant Ecol ›› 2024, Vol. 48 ›› Issue (2): 242-253.DOI: 10.17521/cjpe.2022.0430  cstr: 32100.14.cjpe.2022.0430

Special Issue: 生态化学计量

• Research Articles • Previous Articles     Next Articles

Soil phosphorus availability regulates the response of soil enzyme activity and enzymatic stoichiometry to litter addition in a subtropical forest

WU Jun-Mei1, ZENG Quan-Xin1, MEI Kong-Can1, LIN Hui-Ying1, XIE Huan1, LIU Yuan-Yuan1, XU Jian-Guo2, CHEN Yue-Min1,*()   

  1. 1School of Geographical Science, Fujian Normal University, Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology, Fuzhou 350007, China
    2Daiyun Mountain National Nature Reserve Administration Bureau, Quanzhou, Fujian 362500, China
  • Received:2022-10-31 Accepted:2023-04-06 Online:2024-02-28 Published:2023-04-20
  • Contact: CHEN Yue-Min
  • Supported by:
    Natural Science Foundation of Fujian Province(2020J01142);Natural Science Foundation of Fujian Province(2020J01397)

Abstract:

Aims It is of great significance to explore soil extracellular enzyme activity and its stoichiometry to understand soil nutrient availability and changes in the nutrient requirements of microorganisms. Subtropical forest ecosystems have high net primary productivity, but the availability of phosphorus (P) in soil is low due to severe soil weathering. Under climate change (i.e., warming, elevated CO2 concentration), plant productivity is predicted to increase, which would increase the input of leaf litter. However, it is still unclear whether the effect of increasing litter input on soil enzyme activity and its stoichiometry is affected by soil P availability in the future.

Methods This study investigated the effects of the addition of three kinds of litters (Pinus massoniana, Michelia macclurei and Liquidambar formosa) with different quality (characterized by different leaf C:N or C:P) and P on soil properties and enzyme activities in subtropical low-P soils. By analyzing the stoichiometric ratio of soil enzymes, vector length (VL), and vector angle (VA), the relative nutrient limitation to soil microorganisms and the key regulatory factors were explored.

Important findings The results showed that litter addition increased β-N-acetyl-glucosaminidase and acid phosphatase (ACP) activities. The addition of litter significantly increased VL and VA in the order of M. macclurei > L. formosana > P. massoniana. Litter addition could change the status of nutrient limitation to soil microorganisms, with the degree of changes being related to the quality of litter. Compared with the addition of litter alone, the addition of both litter and P significantly increased the content of available P, and reduced ACP activity and VA, suggesting that P addition could help alleviate P limitation to soil microorganisms under the input of litter. Redundancy analysis results showed that the soil carbon/nitrogen ratio, dissolved organic carbon content, and available P content were the main factors affecting enzyme activities and their stoichiometry. In conclusion, our study found that the response of soil microbial nutrient limitation to litter input in subtropical forest was not only affected by litter quality, but also regulated by soil P availability. This study provides a theoretical reference for the response of microbial nutrient acquisition strategies to different litter inputs and P additions in subtropical forests under future climate change, and is conducive to improving our understanding of the soil biogeochemical cycling in subtropical low P forest ecosystems.

Key words: litter, phosphorus addition, soil enzyme activity, enzymatic stoichiometry, phosphorus limitation