The Biological Engine of the Earth

Contact:
 Professor Karl Ritz


A vast quantity and range of life resides in most soils. The total fresh weight mass of organisms below a temperate grassland can exceed 45 tonnes per hectare, equalling or exceeding the aboveground biomass. A handful of such soil contains billions of bacteria, hundreds of kilometres of fungal hyphae, tens of thousands of protozoa, thousands of nematodes, several hundred insects, arachnids and worms, and hundreds of metres of plant roots. These huge numbers are matched by extreme levels of biodiversity, particularly at the microbial scale where thousands of ‘species’ of bacteria are typically present even in a gram of soil. The soil biota can be regarded as the ‘biological engine of the earth’, since it is implicated in the majority of the key functions soil provides in terms of ecosystem services, by driving many fundamental nutrient cycling processes, soil structural dynamics, degradation of pollutants, regulation of plant communities and erosion control. Microbially-driven soil processes play key roles in underpinning soil fertility, and as such we are highly dependent upon them. The soil biota also mediate global climate change by acting as C sources and sinks, and are involved extensively in the generation of greenhouse gases such as nitrogen oxides and methane.

Our research focuses upon understanding the origins and consequences of soil biodiversity, what governs the way the biological engine works, and how to manage soils in order to maintain a healthy biota. One of the consequences of such extreme diversity is that it is very challenging to characterise or measure soil communities in a meaningful way. Hence we have a particular focus on developing biological indicators of soil quality and in developing techniques that allow the incisive assessment of the state of soil systems.

 

Research projects include:

  • Climate change impacts on soil biota - development of a resistance and resilience assay
  • Development of biological indicators of soil quality
  • Catabolic profiles as indicators of soil microbial functional diversity

PhD projects:

  • Manipulation of plant diversity within grassland buffer margins to enhance soil biodiversity
  • Interactions between biodiversity and survival of microbial pathogens in soil
  • Is thermodynamic efficiency of soil microbial communities related to system maturity and fungal dominance?

Others:

  • Integration of soil fingerprinting techniques for forensic applications
  • Soil-for-Life: A company-scale soil information system