Advice, collaboration, supervision and consultancy

Agroecology - soil ecological impact of farming systems

Farming systems are composed of a range of elements enhancing or depriving a rich soil ecosystem. There is a need to produce models enabling the prediction of the effect of farming systems and a feasible way to do this is to aggregate the components of the farming system at the field level. Cropping systems including GM crops or bioenergy crops should be evaluated using such an approach.

Mesocosms

Mesocosms are complex (soil) model ecosystems including a number of interacting species participating in the soil food web structure. They are more ecologically realistic than the simpler single species test system so commonly employed in ecotoxicology. They are used to study species interactions, decomposition of organic matter and nutrient cycling. In principle all sorts of ecological processes may be investigated in a mesocosm system. What may be difficult and even impossible to study in the field can alternatively be studied in an experimental mesocosm system.

In collaboration with my colleagues from France and Germany mesocosm methodology has been developed and studies were undertaken in basic and applied research projects. The methodology needs to be validated against the desired aims of running it and estimate its predictive value compared to field effects. The dimensioning of the system affecting all variables included and measured should be evaluated to suggest an optimized method. See a selection of publications dealing with mesocosms.

The individual and population level

Laboratory testing on indivduals and population in isolation can be done for materials and substances for which environmental concerns exists. The test guidelines with Folsomia candida, Folsomia fimetaria and Hypoaspis aculeifer is included in the  OECD guideline programme: 232 and 226.

Sludge ERA

Ecological effects assessment of sludge and LAS, linear alkylbenzene sulphonates, has been an occasional activity since the middle of the nineties when organic contaminants in sludge raised concern. See list of sludge related publications.

GMO

project.

Food web structure

The soil food web can be studied in the field, greenhouse or lab systems, in experimental systems including more than one species, e.g. mesocosms. To get information about the food web structure is not a simple task. Assessment of population abundances do not give direct information about the feeding relations between the populations, but stable isotope composition reflects the food sources from which e.g. C and N is derived. This is based on the δ¹³C and δ¹⁵N isotopic signatures and we employ these techniques in our arctic monitoring.

Reproductive biology of Folsomia candida

Some springtails such as F. candida are generally considered to have a parthenogenetic mode of reproduction (thelytokous). This is probably due to the endosymbiont  Wolbachia. We now know that even though F. candida reproduces parthenogenetically there is minute production of males with fully active Wolbachia presence.