Soil Microbial Communities in Grasslands – Biogeography at the Local and Regional Scale

 

Scientific investigators:

Prof. Dr. Ellen Kandeler

Dr. Sven Marhan

Doreen Berner

Runa Boeddinghaus

(University of Hohenheim, Stuttgart)

Previous project phase (2011-2017)

Goals

(University of Hohenheim, Stuttgart)
1. Plant community composition and seasonality in resource partitioning on a local scale
2. Climate, soil texture, and geology show more pronounced effects than land use intensity at a regional scale

 

Methods

 1. Spatial patterns of a following parameters are measured at a subplot of one experimental plot at the Exploratory Schwäbische Alb:

  •    Biogeochemical soil properties
  •    Recalcitrant organic compounds
  •    Metabolic profiling of DOC
  •    PLFA, ergosterol
  •    Abundance of bacteria, archaea, fungi
  •    Denitrifiers
  •    Enzyme activities (C-, N-, P-cycle)
  •    Geostatistics

 

 Working groups participating in this experiment:
Fischer (University of Bern) – plant community compostion, shoot biomass
Schloter (Research Center for Env. Health, Munich) – Archaeal and bacterial nitrifiers, N2 fixing microorganisms
Buscot/Wubet (UFZ Halle) – Ascomycetes, Basidiomycetes, AM mycorrhiza in soil
Bonkowski (University of Cologne) – Protozoa
Rillig, Hempel (FU Berlin) – AM mycorrhiza inside roots, root biomass
Overmann, Friedrich (German Collection of Microorganism and Cell Cultures, Braunschweig; University of Bremen) – Acidobacteria

 2. Sampling of denitrifiers, enzyme activities (C-, N-, P- cycle), PLFA, ergosterol, and biogeochemical soil properties studied at all 50 grassland EPs

 

Previous project phase (2008-2011)

 

Effect of Land-Use Intensity on Spatial Structure and Function of Soil Microbial Communities

 

Scientific investigators:

Prof. Dr. Ellen Kandeler

Dr. Sven Marhan

Dr. Christian Poll

Doreen Berner

(University of Hohenheim, Stuttgart)

This project will clarify whether land-use intensity of grasslands influences functional diversity of soil microorganisms in the three exploratories. The focus will be on C- and N-cycling as key processes in terrestrial ecosystems. We hypothesize that grasslands of different land-use could be classified by general soil microbial properties similar to plant based classification approaches. Therefore, fuzzy modeling will be applied using 1200 reference values that were collected across Europe over the past 20 years. In a next step, we will apply geostatistical techniques on soil enzyme activities, which characterize microbial functioning in C- and N-cycling. We hypothesize that increasing land-use intensity will decrease the spatial heterogeneity of microbial processes by decreasing soil microhabitat and plant diversity. Similarly, we expect land-use to modify specific functions of the microbial community. The density and community structure of denitrifying bacteria as key players of the N-cycle will be assessed by analyzing functional genes (narG, nirK, nirS, nosZ). Linking density of functional genes with nitrate reductase activity will help to understand the regulation of N-cycling in terrestrial ecosystems. All data will be linked to above ground biodiversity and will further enlighten the relationship of ecosystem functioning and biotic diversity. Therefore, information on below-ground functional diversity at different resolution will help to understand the impact of land-use intensity on spatial patterns of grassland plant species.


Field work (soil sampling) and study design:

BILD SCALEMIC