Doctor Kirk Barnett


Kirk BarnettGraduated PhD 2017

Thesis Title

Hidden herbivory, precarious precipitation and punished pastures: Australia's grasslands under root herbivory and altered rainfall

Research Project

Climate models, especially ones for the Australian continent, expect more variable rainfall events as a result of global climate change. This includes reduced annual rainfall and longer periods in between rainfall events. Plant community responses will be highly dependent on how plant groups cope with climatic changes. In addition, root herbivory could dramatically alter these mechanisms by removing root tissue needed to cope with drought. In order to investigate this, we have established grassland plots at the HFE field site utilizing rainout shelters and irrigation to simulate rainfall patterns predicted by current climate models. Treatments applied will consist of reduced annual rainfall (drought), reduced frequency of rainfall events (lengthening periods in between heavy rainfall events), and ambient. In addition to changes in rainfall, a treatment of added root herbivores (inoculation with Scarab larvae) will be applied. Different responses of C4 and C3 grasses are expected under changing rainfall patterns and these should be altered by the increase in root herbivores.

Research Project Supervisors

A/Professor Sally Power and Dr Scott Johnson


Barnett KL, Johnson SN, Power SA, (2018) 'Drought negates growth stimulation due to root herbivory in pasture grasses', Oecologia, vol.188, no.3, pp 777-789

Hasegawa S, Pineiro J, Ochoa-Hueso R, Haigh AM, Rymer PD, Barnett KL, Power SA, (2018) 'Elevated CO2 concentrations reduce C-4 cover and decrease diversity of understorey plant community in a Eucalyptus woodland', Journal of Ecology, vol.106, no.4, pp 1483-1494

Johnson SN, Lopaticki G, Aslam TJ, Barnett K, Frew A, Hartley SE, Hiltpold I, Nielsen UN, Ryalls JMW, (2018) 'Dryland management regimes alter forest habitats and understory arthropod communities', Annals of Applied Biology, vol.172, no.3, pp 282-294

Barnett KL, Facey SL, (2016) 'Grasslands, invertebrates and precipitation: a review of the effects of climate change', Frontiers in Plant Science, (in press) doi: 10.3389/fpls.2016.01196.

Frew A, Barnett K, Riegler M, Nielsen UN, Johnson SN, (2016) 'Belowground ecology of scarabs feeding on grass roots: current knowledge and future directions for management in Australasia', Frontiers in Plant Science, vol.7, p 321

Gibson-Forty EVJ, Barnett KL, Tissue DT, Power SA, (2016) 'Reducing rainfall amount has a greater negative effect on the productivity of grassland plant species than reducing rainfall frequency', Functional Plant Biology, vol.43, no.4, pp 380-391

Johnson SN, Lopaticki G, Barnett K, Facey SL, Powell JR, Hartley SE, (2016) 'An insect ecosystem engineer alleviates drought stress in plants without increasing plant susceptibility to an above-ground herbivore', Functional Ecology, vol.30, no.6, pp 894-902

Marquis RJ, Salazar D, Baer C, Reinhardt J, Priest G, Barnett KL, (2016) 'Ode to Ehrlich and Raven or how herbivorous insects might drive plant speciation', Ecology, vol.97, no.11, pp 2939-2951

Power SA, Barnett KL, Ochoa-Hueso R, Facey SL, Gibson-Forty EVJ, Hartley SE, Nielsen UN, Tissue DT, Johnson SN, (2016) 'DRI-Grass: A new experimental platform for addressing grassland ecosystem responses to future precipitation scenarios in South-East Australia', Frontiers in Plant Science, vol.7, Article no.1373

Torode MD, Barnett KL, Facey SL, Nielsen UN, Power SA, Johnson SN, (2016) 'Altered precipitation impacts on above-and below-ground grassland invertebrates: Summer drought leads to outbreaks in spring', Frontiers in Plant Science, vol.7, Article no.1468

Barnett K, Johnson SN, (2013) 'Chapter One - Living in the Soil Matrix: Abiotic Factors Affecting Root Herbivores', In: Johnson SN, Hiltpold I, Turlings TCJ, Editor(s), Advances in Insect Physiology, Academic Press, vol.45, pp 1-52