Diurnal oscillations in gas production (O2, CO2, CH4, and N2) in soil monoliths

S. K. Sheppard, D. Lloyd

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Soil cores (35 cm long, 7 cm diameter) from the Macaulay Land Use Research Institute's Sourhope Research Station in the Scottish Borders were kept and monitored at constant temperature (18 ± 1°C) for gas production using a 1.6 mm diameter stainless steel probe fitted with a membrane inlet and connected to a quadrupole mass spectrometer. This provided a novel method for on-line, real time monitoring of soil gas dynamics. In closed-system headspace experiments, O2 and CO2 (measured at m/z values 32 and 44, respectively) showed anti-phase diurnal fluctuations in low-intensity simulated daylight and under a light-dark (LD, 12:12 h) regime. O2 increased during periods of illumination and decreased in the dark. The inverse was true for CO2 production. Ar (m/z = 40) concentration and temperature (°C) remained constant throughout the experiments. The same phase-related oscillations, in CO2 and O2 concentrations, were observed at 2 and 5 cm depth in soil cores. The O2 concentration did not oscillate diurnally at 10 cm depth. In below-ground experiments, CH4 (m/z = 15) concentration showed diurnal cycles at 2, 5 and 10 cm depth. The CH4 production had the same diurnal phase cycle as CO2 but with lower amplitude. Evidence of below-ground diurnal oscillations in N2 (m/z = 28) concentration was provided at 5 cm depth. The scale of production and consumption of gases associated with soil-atmosphere interactions and below-ground processes, are shown to be a multifaceted output of several variables. These include light, circadian-controlled physiological rhythms of plants and microbes, and the interactions between these organisms.

Original languageEnglish
Pages (from-to)577-591
Number of pages15
JournalBiological Rhythm Research
Volume33
Issue number5
DOIs
Publication statusPublished - 1 Dec 2002

Keywords

  • CH
  • Circadian rhythms
  • CO
  • Diurnal oscillations
  • N
  • O
  • Soil

ASJC Scopus subject areas

  • Physiology
  • Ecology, Evolution, Behavior and Systematics
  • Physiology (medical)

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