Environmental Chemistry
Environmental Chemistry research has become increasingly focussed on arsenic, an environmental carcinogen, which is widely found to be elevated in the environment and human food-chain. This has lead to the discovery that arsenic contamination leads to levels of arsenic in rice grain hazardous to human health in Bangladesh and USA, a new hypothesis for the cause of elevated arsenic in SE Asian groundwaters and the first characterisation of intact arsenic-phytochelatin complexes in biological tissues.
Arsenic contaminations in Bangladesh (top left), arsenic-induced skin lesions (top right) and the first survey indicating high levels of arsenic in Bangladeshi and US rice (above).
Biosensors and Bioremediation
The Biosensors and Bioremediation group have developed an array of biosensor and used them to pioneer research into the bioavailability of organics and heavy metals in soil. They have developed powerful, diagnostic assays which have become widely and successfully used in comparative ecotoxicological studies and to identify constraints to bioremediation. This has facilitated the establishment of the spin-out company Remedios. They have also developed the first luminescence-based eukaryotic biosensors. These allow in situ study of a wide range of microbial and microfaunal eukaryotes in the soil-plant-water system.
Range of metabolic and catabolic biosensors (left) being used for ecotoxological studies, such as soil pollutant mapping (right).
Global Change
Liz Baggs, Dave Johnson, David Robinson, Jo Smith,
Pete Smith, Rene Van Der Wal, Sarah Woodin
Global Change research has three strands. The first (Smith, Smith, Robinson) focuses on the impacts of climate change on soil carbon stocks, and the potential of altered agricultural practice, soil management, and bioenergy crops to reduce greenhouse gas emissions. Highlights include new evidence of the temperature sensitivity of soil organic matter, the first global analysis of agricultural mitigation potential for all greenhouse gases for all world regions and all mitigation practices (forming the basis of the agricultural mitigation chapter in the authoritative and influential IPCC Fourth Assessment Report), quantification of the contribution of agriculture to the European carbon balance, assessments of the vulnerability of ecosystem services to climate change and new methods to estimate nitrous oxide emissions from fertiliser, and for estimating belowground carbon storage in forests.
Projected changes in European mineral soil carbon under climate change over the next century (left), and annual net primary production (NPP) estimated by the Miami model using MODIS cropland area 2005 (right).
The second strand involves the development and application by Baggs of novel stable isotope techniques, coupled with state-of-the-art gas chromatography and mass spectrometry, to quantify microbial sources of greenhouse gases in soils, to understand the controls and drivers of these processes, and to link them to microbial diversity and activity.
Developing novel isotopomer analysis using a multi collector isotope ratio mass spectrometer (left). This is part of research aiming to better characterise the microbe-driven biochemistry that determine the function of soil (right).
The final strand is concerned with the effects of environmental change on ecosystem processes in northern environments (Woodin, Van Der Wal, Johnson). Significant achievements include advances in understanding the complex interplay between climate warming, increased N deposition, vegetation change, increased herbivory and changes in carbon stocks at high altitudes and latitudes, the first demonstration that increased UVB radiation affects soil microorganisms and provision of clear evidence that UK montane heaths are damaged by nitrogen deposition.
Arctic vegetation Silene acaulis (moss campion) (top) and studying the effect climatic warming on carbon and nitrogen turnover in Svalbard (above).