Dr Feike Dijkstra

Summary

Large amounts of organic carbon and nutrients are stored in soils. Release of soil organic carbon into the atmosphere and nutrients for plant uptake are mediated by microbial processes that are particularly intense at the root-soil interface (the rhizosphere). As a biogeochemist, I am fascinated by how plants interact with these microbial processes affecting carbon and nutrient cycling, particularly in relation to global climate change.

Research Interest

I am interested in responses of terrestrial ecosystems to global change factors such as elevated atmospheric CO₂, global warming, drought and land use change. I am particularly interested in plant-microbial interactions (including rhizosphere effects) affecting carbon and nutrient dynamics. Despite their importance, plant-microbial interactions on carbon and nutrient cycling remain poorly described in ecosystem models, largely because these complex interactions are still not fully understood. Many questions about plant-microbial interactions remain unanswered but are important for a better understanding of carbon and nutrient cycling in a changing environment. For instance:

• How do plant-microbial interactions affecting carbon and nutrient dynamics vary with belowground resource availability (nitrogen, phosphorus, water)?
• How do plant-microbial interactions benefit plant growth?
• To what extent are plant-microbial interactions controlled by C:N:P stoichiometry constraints on plant and microbial growth?

I address these questions using field, greenhouse, and laboratory experiments. My work involves the use of stable isotope techniques and other state-of-the-art methods. I also develop simple dynamic models and use ecosystem simulation models to better understand the importance of plant-microbial interactions for carbon and nutrient cycling in different types of ecosystems affected by global change.

Background

I received a BS degree in Tropical Soil Science and Water Management from the International Agricultural College Deventer, the Netherlands. I received MS and PhD degrees in Environmental Science from Wageningen Agricultural University, the Netherlands. For my PhD research I studied the effects of tree species on calcium cycling in a forest of the northeastern United States in collaboration with scientists from the Cary Institute of Ecosystem Studies, New York, US. After my PhD I worked as a postdoctoral research associate at the University of Minnesota where I conducted research at the Cedar Creek Long-Term-Ecological-Research site. I was involved in the BioCON (Biodiversity, CO₂, and Nitrogen) field experiment studying the effects of plant diversity, elevated atmospheric CO₂(using FACE technology), and nitrogen deposition on soil carbon and nitrogen cycling in a tall grass prairie. I continued to work as a postdoctoral research associate at the University of California, Santa Cruz, to study rhizosphere priming effects of trees and agricultural crops on soil organic matter decomposition. During the three years before joining the University of Sydney I was a research scientist in the Rangeland Resources Research Unit of the US Department of Agriculture (Agricultural Research Service) in Fort Collins, Colorado, where I examined elevated CO₂ and warming effects on carbon and nutrient dynamics in a northern mixed prairie (Prairie Heating And CO₂ Enrichment field experiment, PHACE). In 2011 I received an ARC Future Fellowship. My work has been published in top-ranked journals in the fields of ecology and soil science, including Ecology Letters, Ecology, and Soil Biology and Biochemistry.

Recent Publications

• Dijkstra FA, & JA Morgan. 2011. Elevated CO₂ and Warming Effects on Soil Carbon Sequestration and Greenhouse Gas Exchange in Agroecosystems: A Review. In: M Liebig, A Franzluebbers, & R Follett (eds.), Managing Agricultural Greenhouse Gases, Elsevier, in press.
• Dijkstra FA, GL Hutchinson, JD Reeder, DR LeCain, & JA Morgan. 2011. Elevated CO₂, not defoliation, enhances N cycling and increases short-term soil N immobilization regardless of N addition in a semiarid grassland. Soil Biology and Biochemistry, doi:10.1016/j.soilbio.2011.07.017, in press.
• Carrillo Y, E Pendall, FA Dijkstra, JA Morgan, & JM Newcomb. 2011. Response of soil organic matter pools to elevated CO₂ and warming in a semi-arid grassland. Plant and Soil. In press.
• Morgan JA, DR LeCain, E Pendall, DM Blumenthal, BA Kimball, Y Carrillo, DG Williams, J Heisler-White, FA Dijkstra, & M West. 2011. Carbon dioxide eliminates dessication in warmed semi-arid grassland and C₄ grasses prosper. Nature 476:202-205.
• Augustine DJ, FA Dijkstra, EW Hamilton III, & JA Morgan. 2011. Rhizosphere interactions, carbon allocation, and nitrogen acquisition of two perennial North American grasses in response to defoliation and elevated atmospheric CO₂. Oecologia, 165:755-770.
• Dijkstra FA, JA Morgan, JC von Fischer, & RF Follett. 2011. Elevated CO₂ and warming effects on methane uptake in a semiarid grassland below optimum soil moisture. Journal of Geophysical Research – Biogeosciences, 116, G01007.
• Dijkstra FA, D Blumenthal, JA Morgan, DR LeCain, & RF Follett. 2010. Elevated CO₂ effects on semiarid grassland plants in relation to water availability and competition. Functional Ecology, 24:1152-1161.
• Dijkstra FA, D Blumenthal, JA Morgan, E Pendall, Y Carrillo, & RF Follett. 2010. Contrasting effects of elevated CO₂ and warming on nitrogen cycling in a semiarid grassland. New Phytologist, 187:426-437.
• Dijkstra FA, JA Morgan, D Blumenthal, & RF Follett. 2010. Water limitation and plant inter-specific competition reduce rhizosphere-induced C decomposition and plant N uptake. Soil Biology and Biochemistry, 42:1073-1082.
• Dijkstra FA, JA Morgan, DR LeCain, & RF Follett. 2010. Microbially mediated CH₄ consumption and N₂O emission is affected by elevated CO₂, soil water content, and composition of semi-arid grassland species. Plant and Soil, 329:269-281.

Contact

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