Impact of litter removal on greenhouse gas fluxes, soil nutrients and microbial communities

Michael Zimmermann1, Sonja Leitner1, Lukas Kranzinger1, Orracha Sae-Tun1, Sophie Zechmeister-Boltenstern1
1 Institute of Soil Research, University of Natural Resources and Life Sciences Vienna

P 3.27 in Fluxes between the atmosphere and ecosystems

Poster Session 2 on Tuesday, 16:30-18:00

Different environmental conditions create unique niches that host a variety of living organisms above- and belowground. In forests, soil nutrient cycling is driven by biotic and abiotic factors influencing the decomposition of organic substances through soil microbial activity. Therefore, climate change might alter entire forest ecosystems, which will result in shifts of soil to atmosphere gas fluxes and soil processes.           
In this study, we analysed the influence of the litter layer on soil greenhouse gas fluxes, nutrient cycling and microbial communities in a temperate beech forest (Fagus sylvatica) in Austria. In a paired litter removal experiment, litter was removed from 12 plots of 50 x 50 cm and fluxes for CO2, CH4 and N2O as well as soil chemical and microbial properties determined regularly from summer 2012 to spring 2013. Analysed soil parameters were NH4+, NO3-, PO43-, water soluble sugars, microbial biomass and phospholipid fatty acids (PLFAs).            
Litter removal reduced total soil CO2 emissions by a mean of 35%, whereas Q10 values were higher for the litter removal plots compared to control plots. Furthermore, litter removal increased CH4 uptakes. Soil nutrients did not show any significant differences between litter removal and control plots during the studied year. Litter removal immediately increased bacterial, fungal and arbuscular mycorrhizal abundances in soil, whereas bacteria, particularly Gram+, were the most abundant soil microbes in both control and litter removal plots for the whole study period. Without litter covering, niche conditions for soil microbes varied stronger among seasons, which thus caused a change in microbial community structures. Soil microbial community composition indirectly responded to litter removal through acclimation to soil environmental condition alteration due to litter removal.

Letzte Änderung 04.04.2014