Joseph Holtum

I am a plant ecophysiologist interested in mechanisms that permit plants to survive when times are tough. I focus on how the roughly 6% of plant species that exhibit a water-conserving type of photosynthesis known as crassulacean acid metabolism (CAM) respond to temperature, water-limitation and to changing concentrations of atmospheric CO2. I study Australian CAM clades, species in Central America (in collaboration with Klaus Winter at STRI, Panama), and most recently, SE Asian and New Guinea groups with collaborators in Singapore, PNG and Oxford. Australian species with CAM include many epiphytic orchids and hoyas, ant-plants, succulents of coastal and inland saline areas, temperate and tropical Calandrinia from across the continent, and a few fresh-water species.

I also (i) assist in evaluating growing Agave as a biofuel feedstock crop in the seasonally-dry tropics of Australia. AusAgave, an Australian industry partner, and I are trialling Agave for biomass production, a world first, and (ii) participate in a project that attempts to understand how Australian lowland rainforest may respond to increasing water-limitation.

Long-term projects include a census of Australian CAM species and determining how many orchids and Hoya exhibit CAM and what are the phylogenetic and environmental connections between those species.

In collaboration with Dr Jon Luly (JCU) and Prof Michelle Waycott (Adelaide), I am also attempting to understand the functional biology of Australia's tallest desert tree, Acacia peuce.

With Dr Irwan Lovadi, Tanjungpura University, and Simon Robson (CQU) I am evaluating just how sticky are sundews.