Soil Temperature and Moisture Effects on Soil Respiration and Microbial Community Abundance
ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
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Soil biological processes are influenced by dynamic soil descriptors, such as water potential and temperature, and more stable factors, including organic matter content and particle size distribution. To better understand how soil temperature and soil water potential influence microbial activity, we measured soil respiration in laboratory incubations of four different soils. Though three of the soils had the same soil texture, they varied considerably by pH and soil nutrient concentrations. We found that the soils varied in how their native soil microbes responded to a range of soil water potential and temperature values, with soil activity being highest at approximately 30 C and 33 kPa. Further, the peak respiration rate for the soil with the highest measured organic matter content was 329.8 mg C-CO2 m 2 day 1 and the rate for the soil with the lowest measured organic matter content was 14.7 mg C-CO2 m 2 day 1. Those soils with elevated organic matter content also contained the highest abundance of bacteria and archaea. Across all soils, if the moisture content was optimal but the temperature was around 5 C, the respiration rate was reduced. Therefore, microbial activity may depend more on temperature though moisture clearly had an effect on activity.
- Physical Chemistry
- Geology, Geochemistry and Mineralogy