Impact of extreme weather events on soil microbial community composition and emissions of climate-relevant gases
Abstract
Climate change research anticipates an increase in the frequency and intensity of extreme weather events like severe droughts and heavy rainfalls. In this context, a change of summer rainfall patterns in northern mid-latitudes is expected, which will lead to extended summer drought periods followed by stronger rainfall events. Furthermore, it has been widely agreed that feedback effects between altered precipitation and changed soil emissions of primary and secondary greenhouse gases, such as CO2, CH4, N2O and NOx, could intensify climate change. Most terrestrial ecosystems experience a series of drought-rewetting events per year; however few studies have investigated how increasing frequency and magnitude of these events affects soil processes in situ. With the proposed study, we address the impact of more frequent and more severe drought-rewetting cycles on soil microbiology, C- and nutrient cycling and emissions of climate-relevant gases. To this end, we will simulate two different scenarios of extreme events (short drought periods with little rainfall, and long drought periods followed by heavy rainfall) in a natural Austrian beech forest and determine the responses of soil microbial community composition, soil processes, soil aggregate stability and of all major climate-relevant soil gas emissions (CO2, CH4, N2O, NOx). Our research questions are: 1) What are the effects of increased drought-rewetting frequency on soil C- and nutrient-cycling? 2) Will total soil emissions of climate-relevant gases be reduced by extended drought periods or will potential pulses during rewetting periods compensate or even outweigh this reduction, thereby leading to an increase of the overall fluxes? 3) How do soil microbial communities respond to increased frequency and intensity of drying-rewetting cycles? Field simulations of changed precipitation patterns will be performed with throughfall exclusion via roofs and artificial irrigation in two consecutive years during the entire vegetation period (March until November) to catch inter-annual variations. Two different stress treatments via throughfall exclusion and artificial watering will be applied: a „moderate stress“ treatment with one month long drought periods and little rainfall, and a „severe stress“ treatment with two months long drought periods followed by heavy rainfall. Climate-relevant gases will be continuously measured with an automated gas flux measurement system with mobile flux chambers. Soil and water fractions will be sampled bi-weekly and analyzed in the laboratory for bulk and microbial C, N and P and mobile nutrients. Microbial community analysis will be determined via analysis of phospholipid fatty acids (PLFAs) and ergosterol, and soil aggregate stability via ultrasonication. The BOKU University forest Rosalia, Austria, where the proposed study will be conducted, is venue of many national and international research projects and is associated with the ExpeER network as ‘Related Sites’.
Publikationen
Impact of repeated dry-wet cycles on soil CO2 efflux and extracellular enzyme activities in a beech forest
Autoren: Leitner, S; Zimmermann, M; Holtermann, C; Keiblinger, K; Saronjic, N; Zechmeister-Boltenstern, S Jahr: 2014
Conference & Workshop proceedings, paper, abstract
Impact of repeated dry-wet cycles on soil greenhouse gas emissions, extracellular enzyme activity and nutrient cycling in a temperate forest
Autoren: Leitner, S; Zimmermann, M; Bockholt, J; Schartner, M; Brugner, P; Holtermann, C; Zechmeister-Boltenstern, S Jahr: 2014
Conference & Workshop proceedings, paper, abstract
Impact of droughts and heavy rain on greenhouse gas emissions and soil microbial activities in a beech forest
Autoren: Zechmeister-Boltenstern, S; Leitner, S; Zimmermann, M Jahr: 2014
Conference & Workshop proceedings, paper, abstract
Impact of repeated dry-wet cycles on soil CO2 efflux in a beech forest
Autoren: Leitner, S; Saronjic, N; Kobler, J; Holtermann, C; Zechmeister-Boltenstern, S; Zimmermann, M Jahr: 2015
Conference & Workshop proceedings, paper, abstract
How do soil microbial communities react on droughts and heavy rainfall events?
Autoren: Saronjic, N; Leitner, S; Keiblinger, K; Zechmeister-Boltenstern, S; Zimmermann, M Jahr: 2015
Conference & Workshop proceedings, paper, abstract
Response of Soil Respiration to Repeated Extreme Events in a Temperate Beech Forest in Austria
Autoren: Leitner, S; Kobler, J; Holtermann, C; Saronjic, N; Zechmeister-Boltenstern, S; Zimmermann, M Jahr: 2015
Conference & Workshop proceedings, paper, abstract
Contribution of litter layer to soil greenhouse gas emissions in a temperate beech forest
Autoren: Leitner, S; Sae-Tun, O; Kranzinger, L; Zechmeister-Boltenstern, S; Zimmermann, M Jahr: 2016
Journal articles
Moisture sensitivity of soil respiration in the context of extreme dry-wet events
Autoren: Leitner, S; Kobler, J; Zimmermann, M; Zechmeister-Boltenstern, S Jahr: 2016
Conference & Workshop proceedings, paper, abstract
Linking NO, N2O and CO2 emission peaks to the mobilization of mineral N upon rewetting of dry soil
Autoren: Leitner, S; Homyak, PM; Blankinship, JC; Eberwein, J; Jenerette, D; Zechmeister-Boltenstern, S; Schimel, JP Jahr: 2016
Conference & Workshop proceedings, paper, abstract
Response of soil microbial communities to droughts and heavy rainfall events
Autoren: Saronjic N, Leitner S, Keiblinger K, Zechmeister-Boltenstern S, Zimmermann M Jahr: 2016
Conference & Workshop proceedings, paper, abstract
Project staff
Sophie Zechmeister-Boltenstern
Univ.Prof. Dr.phil. Sophie Zechmeister-Boltenstern
sophie.zechmeister@boku.ac.at
Tel: +43 1 47654-91111
Project Leader
01.01.2013 - 29.02.2016