A project undertaken at Macquarie University, and supervised by Andrea Westerband
For plants living in Australia, life is challenging. Australia is home to some of the world’s driest (after Antarctica) and most nutrient-poor soils, and living under such extreme conditions can only be accomplished with the right combination of morphological and physiological features. For example, many native plants growing on low nutrients have specialized root systems to take up what little soil nutrients are available, while other plants growing on dry sites have developed tough and thick leaves that are highly efficient at using water.
Given that global climate change models are projecting rising temperatures and ever more severe droughts, how will Australian plants adapt to cope? In this project we explore how native plants have adapted their physiology to suit the Australian landscape. We investigate how plants balance their investments in two key processes: leaf photosynthesis (carbon fixation) and water use (transpiration).
This project will focus on how plants use water and nitrogen during photosynthesis and, specifically, how evolution has shaped the way that plants balance these resources to match their environmental conditions. To carry out this work, we will merge existing datasets with a highly targeted field campaign across Australia. In the field, we measure rates of photosynthesis and water loss using sophisticated physiological equipment. We also collect soils at locations where we have measured photosynthesis, to determine how photosynthesis changes across a range of soil nutrient levels.
Project lead, Andrea Westerband, places recently severed plant stems in water while preparing to measure photosynthesis with a LI-COR 6800, a machine that tracks changes in carbon dioxide and water vapor levels.
Research assistant Shubham Chhajed and volunteer An Tran collect one of several soil samples at a field site in NT. The soil is ultimately sent to a research facility to determine its pH and soil nutrient concentrations.
This project will allow us to better understand how Australia’s environment has shaped the evolution of its plant species. These findings will not only improve our understanding of how Australia’s plants have evolved, but will also shed light on how Australian plants may further evolve to cope with increasingly extreme environmental conditions.