Download Research project BE-CH4 Title: Land

Research project
BE-CH4
Title:
Land-use intensity effects on soil methane cycling microbes in
grassland and forest soils
Project leader:
Steffen Kolb
Duration:
01/04/2017 – 31/03/2020
Core topic (ZALF):
Landscape Processes
Promoter:
DFG - Deutsche Forschungsgemeinschaft
Objective:
Methane (CH4) is, beside CO2 the second most important greenhouse gas (GHG). Current
atmospheric methane concentrations are strongly increasing since 2007, which is assumed to
be predominantly of anthropogenic origin and likely related to intensify agriculture for food
production. Thus, one major challenge for today´s agriculture is to adjust land-use intensity
to ensure productive and at the same time sustainable crop farming systems to balance GHG
emissions and increasing food demands of a growing world population. Two fundamentally
different groups of prokaryotes are crucial for CH4 cycling in soils. Methanotrophic bacteria
(MOB) act as biological CH4 filter by oxidizing atmospheric CH4 and that CH4, which is
produced by methanogenic archaea before it reaches the atmosphere. It is currently unclear
how differences in land-use intensity control the functional diversity and activity of these key
microorganisms in the soil methane cycle. Preliminary data indicate that high land-use
intensity in well aerated grassland soils negatively impacts methane oxidation. However,
almost nothing is known about the influence of land-use intensity on spatial and temporal
dynamics of methanotrophs and methanogens. We have therefore assembled an
interdisciplinary consortium of experts from soil science, microbiology and metagenomics
with well-documented background and complementary expertise in soil GHG emissions,
methanotrophic and methanogenic prokaryotes. Using a unique combination of stateof-theart approaches, we will use the ideal setting of the Biodiversity Exploratories as platform to
address pressing questions about the effect of land-use intensity on the functional diversity
and activity of these key microorganisms in the soil methane cycle. We have laid out a set of
objectives and hypotheses that will be tested in two work packages (WP). WP1 focusses on
the responses of MOB and mediated methane fluxes to land-use intensity in 300 grassland
and forest soils, where the relationship between methane oxidation and abundance and
diversity of methanotrophic bacteria and environmental properties will be studied by
methane flux measurements and qualitative and quantitative PCR, respectively. In WP2 we
will focus on the seasonal and diurnal dynamics in the activity of methanogenic and
methanotrophic prokaryotes (using metatranscriptome and methane flux data) and to which
extent the dynamics are influenced by grassland land-use intensity. We will focus on
comparison between grasslands on water affected Histosols and well-aerated Leptosols. Our
project BE_CH4 will contribute urgently needed knowledge on the influence of grassland and
forest land-use intensity on spatial and temporal dynamics of methane cycling microbes that
ultimately control methane fluxes in soils.