TY - JOUR
T1 - Partial drying accelerates bacterial growth recovery to rewetting
AU - Meisner, Annelein
AU - Leizeaga, Ainara
AU - Rousk, Johannes
AU - Bååth, Erland
PY - 2017/9
Y1 - 2017/9
N2 - Fluctuations in soil moisture create drying-rewetting events affecting the activity of microorganisms.
Microbial responses to drying-rewetting are mostly studied in soils that are air-dried before rewetting.
Upon rewetting, two patterns of bacterial growth have been observed. In the Type 1 pattern, bacterial
growth rates increase immediately in a linear fashion. In the Type 2 pattern, bacterial growth rates increase
exponentially after a lag period. However, soils are often only partially dried. Partial drying (higher
remaining moisture content before rewetting) may be considered a less harsh treatment compared with
air-drying. We hypothesized that a soil with a Type 2 response upon rewetting air-dried soil would
transform into a Type 1 response if dried partially before rewetting. Two soils were dried to a gradient of
different moisture content. Respiration and bacterial growth rates were then measured before and
during 48 h after rewetting to 50% of water holding capacity (WHC). Initial moisture content determined
growth and respiration in a sigmoidal fashion, with lowest activity in air-dried soil and maximum above
ca. 30% WHC. Partial drying resulted in shorter lag periods, shorter recovery times and lower maximum
bacterial growth rates after rewetting. The respiration after rewetting was lower when soil was partially
dried and higher when soils were air-dried. The threshold moisture content where transition from a Type
2 to a Type 1 response occurred was about 14% WHC, while >30% WHC resulted in no rewetting effect.
We combine our result with other recent reports to propose a framework of response patterns after
drying-rewetting, where the harshness of drying determines the response pattern of bacteria upon
rewetting dried soils.
AB - Fluctuations in soil moisture create drying-rewetting events affecting the activity of microorganisms.
Microbial responses to drying-rewetting are mostly studied in soils that are air-dried before rewetting.
Upon rewetting, two patterns of bacterial growth have been observed. In the Type 1 pattern, bacterial
growth rates increase immediately in a linear fashion. In the Type 2 pattern, bacterial growth rates increase
exponentially after a lag period. However, soils are often only partially dried. Partial drying (higher
remaining moisture content before rewetting) may be considered a less harsh treatment compared with
air-drying. We hypothesized that a soil with a Type 2 response upon rewetting air-dried soil would
transform into a Type 1 response if dried partially before rewetting. Two soils were dried to a gradient of
different moisture content. Respiration and bacterial growth rates were then measured before and
during 48 h after rewetting to 50% of water holding capacity (WHC). Initial moisture content determined
growth and respiration in a sigmoidal fashion, with lowest activity in air-dried soil and maximum above
ca. 30% WHC. Partial drying resulted in shorter lag periods, shorter recovery times and lower maximum
bacterial growth rates after rewetting. The respiration after rewetting was lower when soil was partially
dried and higher when soils were air-dried. The threshold moisture content where transition from a Type
2 to a Type 1 response occurred was about 14% WHC, while >30% WHC resulted in no rewetting effect.
We combine our result with other recent reports to propose a framework of response patterns after
drying-rewetting, where the harshness of drying determines the response pattern of bacteria upon
rewetting dried soils.
U2 - 10.1016/j.soilbio.2017.05.016
DO - 10.1016/j.soilbio.2017.05.016
M3 - Journal article
SN - 0038-0717
VL - 112
SP - 269
EP - 276
JO - Soil Biology & Biochemistry
JF - Soil Biology & Biochemistry
ER -