The majority of soil and sedimentary organic matter has not been chemically characterized at the molecular-level. The lack of understanding of soil organic matter structure makes it difficult to study how climate change and other human-induced processes will alter organic matter dynamics and functions in various ecosystems. We are developing and using advanced analytical tools to monitor organic matter composition and biogeochemistry with various aspects of environmental change. This includes organic matter biomarkers, which can be used to trace the fate of organic matter and assess its degree of oxidation, and solution-state and solid-state NMR spectroscopy (see Simpson & Simpson, 2012 for more information about the methods we use).
We are currently focusing on Forest and Arctic ecosystems as these are highly sensitive to environmental change. We are collaborating with researchers at various Long-Term Ecological Research Sites to study how soil warming and nitrogen fertilization alter soil organic matter composition. Another area of interest is how variation in detrital inputs alters soil organic matter composition. We are also studying soil, sedimentary and dissolved organic matter biogeochemistry at the Cape Bounty Arctic Watershed Observatory in the Canadian High Arctic.
We are developing methods to monitor ecosystem health that are rapid, routine, and quantitative. These methods directly measure the health of keystone organisms for both aquatic and terrestrial ecosystems. Environmental metabolomics is highly sensitive to small perturbations within an organism and can be used to monitor organism stress (see Lankadurai et al. 2013). We have developed methods for Eisenia fetida (a commonly studied earthworm in soil ecotoxicity) and are currently working on methods for Daphnia magna (a keystone species for studying toxicity and ecological food webs in freshwater ecosystems). We use both 1H NMR and LC-MS/MS for charazterizing the metabolome of model organisms.