Dr A Boom, Dr J C Berrio
No more applications being accepted
Competition Funded PhD Project (Students Worldwide)
About the Project
Plant waxes from leaf coatings are widely dispersed by wind and can be found everywhere on earth. Due to their chemically resistant nature, they tend to be preserved in sedimentary archives for millions of years. They are used as biomarkers in paleoclimate research as they represent the molecular remains of past vegetation. As such they are of fundamental importance because the isotopic ratios of carbon (δ13C) and hydrogen (δD) are directly related to metabolism of specific plant functional types and ecophysiological conditions (Sachse et al. (2012). δD signatures of plant waxes in particular show a strong correlation to hydrological conditions at times of plant growth (Kahmen et al. 2013) and their use palaeoclimate studies has shown that δD of leaf waxes can be used to reconstruct aspects of past rainfall (Tierney et al. 2008), in particular the amount of precipitation (Schefuss et al. 2005). To fully utilize this palaeoclimate proxy it is important to understand the modern day plant-deuterium relationships. Understanding δD in leaf waxes from modern plants, in the context of the hydrological cycle, is key to interpretations of biomarker δD records of the past. The Neotropical Andes is a key location for palaeoclimate research due to its wealth of Holocene/Quaternary sedimentary archives and its critical role in the global climate system (Boom et al. 2001). For example the hydrological cycle of the Andes affects that of the modern day Amazon basin, the largest tropical watershed in the world. The proposed project involves the retrieval of sedimentary archives including a systematic sampling of Andean plant taxa and vegetation units along a range of well-defined environmental gradients. Ground and meteoric water will be collected at specific intervals to obtain better insights into the isotopic behaviour of the source water through time. Leaflipid distribtutions from plants will be investigated in relation to envrionmental gradients and long term changes from sedimentary records. The results of this study will provide new insights into the hydrological cycle of the Northern Andes, and its plant interactions, and ultimately seeks to facilitate significantly improved palaeoclimatological reconstructions.
Funding Notes
For UK Students: Fully funded College of Science and Engineering studentship available, 3 year duration.
For EU Students: Fully funded College of Science and Engineering studentship available, 3 year duration
For International (Non-EU) Students: Stipend and Home/EU level fee waiver available, 3 years duration. International students will need to provide additional funds for remainder of tuition fees.
Please direct informal enquiries to the project supervisor.
If you wish to apply formally, please do so via: https://www2.le.ac.uk/colleges/scieng/research/pgr and selecting the project from the list.
References
A Boom, et al. (2001) CO2 and temperature-controlled altitudinal shifts of C4 and C3 dominated grasslands allow reconstruction of palaeoatmospheric pCO2. Palaeogeography, Palaeoclimatology, Palaeoecology 177 (1), 151-168.
E Schefuß, S Schouten, RR Schneider (2005) Climatic controls on central African hydrology during the past 20,000 years. Nature 437 (7061), 1003-1006.
Sachse et al. 2012 Molecular paleohydrology: interpreting the Hydrogen-isotopic composition of lipid biomarkers from photosynthesizing organisms, Annu. Rev. Earth Planet. Sci. 40:221-249.
Tierney et al. 2008 Northern Hemisphere Controls on
Tropical Southeast African Climate During the Past 60,000 Years. Science 322, 252-255.