Schmitt, A; Glaser, B; Borken, W; Matzner, E: Repeated freeze-thaw cycles changed organic matter quality in a temperate forest soil, Journal of Plant Nutrition and Soil Science, 171, 707-718 (2008)
Under temperate climate, the frequency of extreme weather events such as intensive freezing or frequent thawing periods during winter might increase in the future. It was shown that frost and subsequent thawing may affect the fluxes of C and N in soils. In a laboratory study, we investigated the effect of frost intensity and repeated freeze/thaw cycles on the quality and quantity of soil organic matter (SOM) in a Haplic Podzol from a Norway spruce forest. Undisturbed soil columns comprising organic layer and top mineral soil were treated as followed: Control (+5 °C), frost at –3 °C, –8 °C and –13 °C. After a two-week freezing period, frozen soils were thawed at +5 °C and irrigated with 80 mm water at a rate of 4 mm per day. Lignin contents were not significantly affected by repeated freeze/thaw cycles. Phospholipid fatty acid (PLFA) contents decreased in the mineral soil and PLFA patterns indicate that fungi are more susceptible to soil frost than bacteria. Amounts of both plant and microbial sugars generally decreased with increasing frost intensity. These changes cannot be explained by increased mineralization of sugars or by leaching with DOM nor by a decreased microbial activity and thus sugar production with increasing frost intensity. Also physical stabilization of sugars due to frost-induced changes in soil structure can be ruled out as sugar extraction was carried out on ground bulk soil. Therefore, the only possible explanation for the disappearance of plant and microbial sugars upon soil freezing are chemical alterations of sugar molecules leading to SOM stabilization.
Aktuelle Termine
Do. 21.01.2021
The impact of trees on soil organic carbon dynamics in the Subarctic - Priming effects and microbial N mining
Do. 28.01.2021
BayCEER Mitgliederversammlung
Do. 04.02.2021
Investigating communal pathogen defense and its role in social evolution
Do. 15.04.2021
- folgt -
Do. 22.04.2021
- folgt -
BayCEER Blog
Why Science Communication?
Stoichiometric controls of C and N cycling
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
Picky carnivorous plants?
RSS Blog als RSS Feed
Wetter Versuchsflächen
Luftdruck (356m): 978.6 hPa
Lufttemperatur: 1.5 °C
Niederschlag: 2.7 mm/24h
Sonnenschein: 4 h/d
Wind (Höhe 17m): 11.1 km/h
Wind (Max.): 20.9 km/h
Windrichtung: SW

Globalstrahlung: 17 W/m²
Wind (Höhe 32m): 0.0 km/h

Diese Webseite verwendet Cookies. weitere Informationen