Thesis Topic: Examination of groundwater dependent ecosystem’s ecophysilogical traits and their responses to climate change
Supervisors: Professor Derek Eamus, Dr James Cleverly, Dr Melanie Zeppel (MU)
PhD conferred: 2014
Groundwater is defined as the saturated zone of the regolith and its associated capillary fringe. Groundwater dependent ecosystems (GDEs) are important elements in the landscape whose current composition, structure and function are reliant on the supply of groundwater. They are important because of their conservation, biodiversity, ecological, social and economic values. GDEs have a key role in the hydrological cycle of their catchment. There is a clear need to better understand their function, how they impact their environment and how they are affected by their environment. This information will also provide a valuable tool to assist in the ability to predict the nature and scale of vegetation response to variation in groundwater level. Furthermore understanding ecohydrological function of vegetation can contribute to a management of water resources. The proposed research is aimed at providing insight into the functional and structural attributes of GDEs.
During this project I will examine two classes of ecosystems which are groundwater dependent ecosystems and non groundwater dependent ecosystems. This thesis will focus on a comparative analysis of the ecophysiology and ecohydrology of groundwater dependent ecosystems and examine potential impacts of climate change on those GDEs through application of a SPA model. The main objectives of this research are:
- To compare the ecophysiology of trees in GDEs with trees in non-GDEs.
To address the first objective, measurements will be made at leaf, tree and stand scales at sites which do and don’t have access to groundwater. Specifically, trees ecophysiological traits which are related to their water use will be measured at GDEs and non-GDEs and compared for statistical differences. Each variable will be measured over several seasons and under different climatic conditions (e.g. contrasting soil moisture availability and vapour pressure deficit) to provide a clear description of the ecophysiology of GDEs and non-GDEs.
- To understand different responses of GDEs and non-GDEs to climate change using a detailed mechanistic ecophysiological SPA model.
To address this aim, the SPA model of Williams et al 1996, will be parameterized for SPA using data obtained in (1) above. Using future climate scenarios, I will compare and contrast the behavior of GDEs and non-GDEs under current and future climates.