Dr. Elizabeth Webb

Laboratory for Stable Isotope Science (LSIS)

Liz Webb

Associate Professor & Graduate Chair
Ph.D. Western University, 2000
Office: BGS 0168
Lab: BGS 0159, WSC 54
Phone: (519) 661-2111 x.80208
Fax: (519) 661-3198
Email: ewebb5@uwo.ca
Laboratory for Stable Isotope Science (LSIS) Webpage


Research Interests

Stable-isotope biogeochemistry as applied to: interactions among the soil-plant-atmosphere continuum, paleoclimate models based on the isotopic analysis of ancient plant materials, carbon sequestration, water resource availability and ecosystem resilience in regions with high rates of vegetation change.

Selected Publications

  • WEBB E.A. and Longstaffe F.J. (2010) Limitations on environmental signals in the δ13C values of phytoliths from a North American C4 prairie grass.  Geochimica et Cosmochimica Acta 74, 3041-3050. doi: 10.1016/j.gca.2010.03.006
  • Prentice A. and WEBB E.A. (2010) A comparison of extraction techniques on the stable carbon isotope composition of soil humic substances.  Geoderma 155, 1-9.
  • WEBB E.A., Schwarcz H.P., Jensen C.T., Terry R.E., Moriarty M.D. and Emery K.F. (2007) Stable carbon isotope signature of ancient maize agriculture in the soils of Motul de San José, Guatemala. In: Advances in Archaeological Approaches to Soil Chemistry (eds. C. Wells and R.E. Terry); Geoarchaeology: An International Journal 22, 291-312.
  • WEBB E.A. and Longstaffe F.J. (2006) Identifying the δ18O signature of precipitation in grass cellulose and phytoliths: refining the paleoclimate model. Geochimica et Cosmochimica Acta 70, 2417-2426. doi: 10.1016/j.gca.2006.02.024
  • WEBB E.A., Schwarcz H.P. and Healy P.F. (2004) Detection of ancient maize in lowland Maya soils using stable carbon isotopes: evidence from Caracol, Belize. Journal of Archaeological Science 31, 1039-1052.
  • WEBB E.A. and Longstaffe F.J. (2003) The relationship between phytolith- and plant-water δ18O values in grasses. Geochimica et Cosmochimica Acta 67, 1437-1449.
  • WEBB E.A. and Longstaffe F.J. (2002) Climatic influences on the oxygen isotopic composition of biogenic silica in prairie grass. Geochimica et Cosmochimica Acta 66, 1891-1904.

Courses Taught

Earth Sciences   1081a/b      Sustainability in a Material Society
Earth Sciences   4490           Undergraduate thesis – Coordinator
Earth Sciences   3341b         Waters and Geochemical Cycles
Earth Sciences   4431a         Isotope Geochemistry in Environmental Sciences
Geology            9556           Advanced Stable Isotope Geochemistry – Low Temp
Geology            9506           Introductory Stable Isotope Geochemistry
Geology            9560           Improving Research Skills in Earth Sciences

Students

Zhenzhen Huang, PhD candidate (2006-present). Joint-supervisor: Fred Longstaffe
Determining the relationship between the oxygen isotope composition of phytoliths and plant water under controlled climate conditions for high silica accumulators.

Andrea Prentice, PhD candidate (2009-2014).
Physical and isotopic changes of silica phytoliths during weathering and partial dissolution: Assessing the potential of using soil-phytolith assemblages as a paleoclimatic indicator.

Michael Hamilton, MSc candidate (2009-2012).
Assessment of the oxygen-isotope variations that occur in char formed under different burning conditions.


Future Graduate Projects:

  • Understanding plant water isotope signals preserved in plant organic matter
  • Calcite, calcium oxalate and silica biomineralization in plants: developing a robust, multi-proxy paleoclimate model.
  • Testing the use of Si-isotopes as an indicator of nutrient availability and weathering rates in agricultural soils.
  • Reconstructing fire history across the North American prairies: determining the link between fire frequency, fire temperature and climate.
  • Determining ancient aridity based on the iron- and oxygen-isotope signature of botanical magnetite in the terrestrial plant-soil system
  • Biomineralization processes in thermoregulating plants