Carbon cycle models are used to assess how future carbon policy scenarios will influence atmospheric carbon pools and climate. The accuracy of those models depends on our understanding of major pathways in the carbon cycle. One such pathway, the decay of dead plant material (litter), is responsible for releasing more carbon into the atmosphere each year than the combustion of fossil fuel. Litter decay in forests is reasonably well understood, but both the rate and temporal pattern of litter decay are different in deserts. The effects of direct sunlight on litter may increase the rate of decay, while the lack of moisture may reduce microbial activity and decrease the decay rate. This project will test whether the optical properties of litter produced by desert plants contribute to the different pattern of litter decay. Laboratory and field experiments will be used to test the importance of sunlight as an agent of litter decay relative to other mechanisms such as microbial activity.
This research, which will be conducted in the Sonoran Desert, will contribute to our understanding of carbon cycling in deserts and in other ecosystems where litter is exposed to intense sunlight (e.g. grasslands and agricultural systems).The investigators will develop a website that contains a guide to litter decomposition for K12 students, a companion guide to aid teachers in conducting litter decomposition experiments, and they will solicit K12 teachers to take part in this experiment. This project will provide research experience for K12 students and teachers, and undergraduate and graduate students.
