[Soil enzyme activities and their stoichiometry at different altitudes in Helan Mountains, Northwest China]

Ying Yong Sheng Tai Xue Bao. 2021 Sep;32(9):3045-3052. doi: 10.13287/j.1001-9332.202109.021.
[Article in Chinese]

Abstract

Understanding altitudinal variation characteristics and driving mechanism of soil enzyme activities and their stoichiometry is of great significance for studying nutrient cycling in fragile mountain forest ecosystems. In this study, we collected soil samples from different altitudes (1380-2438 m) in Helan Mountains to analyze the altitudinal changes in soil physicochemical properties, soil enzyme activities and their stoichiometry and its influencing factors. The results showed that the activities of β-glucosidase (βG) and β-N-acetylglucosaminidase (NAG) and the enzyme activities ratios of soil C/N and soil C/P firstly increased and then decreased with increasing altitude, which all peaked at 2139 m. Alkaline phosphatase (AKP) activities increased with the increases of altitude, with the maximum being found at 2438 m. However, L-leucine aminopeptidase (LAP) activities and soil N/P enzyme activities ratios did not change with increasing altitude. Compared with the soil enzyme stoichiometry in other regions of the world, Helan Mountains showed a certain degree of N limitation. Except for LAP, the activities of the other three enzymes were significantly positively correlated with the ratios of soil organic carbon/total nitrogen, soil organic carbon/total phosphorus, and total nitrogen/total phosphorus, and negatively correlated with pH. The LAP, soil C/P enzyme activities ratios and soil N/P enzyme activities ratios showed significant negative correlation with TP. In addition, AKP was significantly negatively correlated with soil bulk density.

探讨干旱区脆弱山地森林生态系统土壤酶活性及其化学计量比沿海拔的变化特征及影响机制,对研究脆弱生态系统养分循环具有重要意义。本研究以贺兰山不同海拔(1380~2438 m)土壤为对象,分析土壤理化性质、土壤酶活性及酶化学计量比沿海拔的变化及其影响因素。结果表明: β-葡萄糖苷酶(βG)、β-N-乙酰氨基葡萄糖苷酶(NAG)、土壤C/N和土壤C/P酶活性比值均随海拔升高表现出先增后减的变化趋势,在海拔2139 m处均处于较高水平;碱性磷酸酶(AKP)活性随海拔的升高整体上呈递增的趋势,在海拔2438 m处最高;亮氨酸氨基肽酶(LAP)活性和土壤N/P酶活性比值随海拔升高变化趋势不显著。通过对比全球土壤酶化学计量值发现,贺兰山存在一定程度的N限制。除LAP外,其余3种酶活性均与土壤有机碳/全氮、土壤有机碳/全磷和全氮/全磷呈极显著正相关,与土壤pH值呈极显著负相关;LAP、土壤C/P和土壤N/P酶活性比值均与全磷呈极显著负相关。此外,AKP与土壤容重呈极显著负相关。.

Keywords: Helan Mountains; altitude; environmental factor; enzyme stoichiometry; soil enzyme.

MeSH terms

  • Altitude*
  • Carbon / analysis
  • China
  • Ecosystem
  • Soil*

Substances

  • Soil
  • Carbon