Dr John Morgan
Plant Ecologist, College of Science, Health and Engineering
Current plant ecology research
Our research is conducted in a diverse range of ecosystems. We focus our attention on temperate native grasslands, semi-arid woodlands, on alpine ecosystems and coastal forests. These allow us to test ideas about the factors that govern species diversity, as well as how communities recover after disturbance and persist in the face of environmental change.
- What factors confer ecological resilience to climate change (warming, drying) in ecosystems where migration is unlikely to keep pace with change?
- How will climate change affect species confined to mountain tops? Will they lose their ecological niche, or be forced out by better competitors?
- Will loss of snowcover make alpine plants more vulnerable to frost?
- How important is climate-driven recruitment (as opposed to fire recruitment) and how might this be affected by changes in the frequency and intensity of drought?
- Can fire be used to recover ecosystems such as coastal grassy woodlands that have been invaded by fire-sensitive native shrubs?
- How does changing from one disturbance regime (e.g. grazing) to fire affect ecosystem diversity and function?
- What effect does re-introducing fire into long-unburned native ecosystems have on ecosystem stability?
- How does fire severity affect the rate of recovery of native ecosystems?
Species diversity and coexistence
- Woodlands in western Victoria are some of the most species-rich ecosystems in Australia. What allows all of these species to coexist in small areas? How important are stochastic processes?
- Using the Nutrient Network (www.nutnet.umn.edu), we ask: to what extent are plant production and diversity co-limited by multiple nutrients in herbaceous-dominated communities? And, under what conditions do grazers or fertilization control plant biomass, diversity, and composition?
Long-term vegetation dynamics and species extinctions
- In south-eastern Australia, many vegetation types exist in an agricultural setting, i.e. are fragmented. Revisitation studies allow us to follow the trajectory of populations in small remnants and ask: are small populations more vulnerable to local extinction? Are demographic or genetic processes more important to persistence (in the short-term)?
We are also currently investigating:
- linkages between resource availability and community productivity, diversity and invasion
- using grazing to advantage conservation outcomes in native grasslands
- tree dynamics in long unburned forests
- how native grasses respond to fire
- seed biology of Australian native grasses