Simone Cesarz, Dr. Christian Platner, Prof. Dr. Stefan Scheu,
Prof. Dr. Matthias Schaefer

Biodiversity manipulation in the rhizosphere and in the soil - the fauna

The influence of the soil fauna on plant-based and soil-based processes is studied with emphasis on the rhizosphere and on groups of the mesofauna. The systems analysed vary in tree species diversity. There are four approaches:
(1) Container experiments with beech and ash trees. Influencing variables on plant growth and soil chemical status are tree species, litter and earthworms.
(2) Rhizocosm experiments with different treatments mainly concerning the soil mesofauna in the rhizosphere.
(3) Microcosm experiments with young trees and different faunal treatments, e.g. earthworms with their burrows, ant nests or varying diversity of collembolans and oribatid mites.
(4) Food web studies in the field with varying diversities of plants and animals; a key method are stable isotope analyses.

Diana Grubert, Dr. Olaf Butenschön, Prof. Dr. Stefan Scheu

Litter quality and tree species identity: Effects on soil food web structure

In autumn 2010 a tree litter diversity experiment will be set up by planting seedlings of four different deciduous tree species (ash, beech, lime and maple). Tree and litter diversity will be manipulated independently in a full factorial design to investigate the contribution of above- and belowground diversity on ecosystem functioning and stability.
My main research interest is the structure and functioning of soil food webs, in particular the differentiation between aboveground (leaf litter) and belowground (root litter and exudates) carbon resources fueling and sustaining soil food web diversity. Soil samples will be taken at regular intervals in the established diversity experiment; animals will be extracted and identified. Phospholipid fatty acid analyses and the measurement of natural stable isotope ratios will complete my work. Generally, I hope to answer the question if the carbon input by aboveground litter has a stronger effect on soil fauna community structure and diversity than the root derived carbon, or vice versa.