James Cook University
Caroline Chong
Overview | Research Aims | Research Strategies
| Supervisors |
Australian dry land river systems are uniquely complex
environments characterised by extreme physical, biological and
hydrologic variability. An outstanding challenge of tropical
riparian research is to understand the ecology of native
vegetation, and the functional role physical processes may play in
driving species population dynamics and persistence. The extant
lack of such ecological knowledge is a critical consideration in
the development of riparian conservation and management
strategies.
Melaleuca (the paperbark)is a conspicuous native element
of the tropical riparian environment, yet little is known of its
basic ecology. The ‘broad-leaved’ M. leucadendra
group dominates the ecologically challenging, flood-prone zone of
riverbanks and is therefore a model taxon to investigate
relationships between environmental variability and biological
functioning.
Through this research project, I aim to gain insight into the
regeneration ecology of M. leucadendra and, in particular,
an understanding of how interaction between physical, ecological
and genetic processes may govern population demographics and
functioning in this riparian dominant species.
My specific research aims include:
- Investigation of vegetative (clonal) growth: spatial
structuring and extent of genetic individuals
- Identification of population structure, size and connectivity:
spatial genetic patterns of variation at local (river reach) to
regional (catchment and inter-catchment) spatial scales
- Investigation of interactive processes: evaluate influence of
geographic distance, location in river network (upstream to
downstream), hydrologic potential (stream order), physical site
characteristics, and biological parameters (plant life stage) on
detected patterns of genetic and population structuring
- Understanding of species regeneration strategies: ecological
investigations of seed bank dynamics and seedling resilience to
disturbance
- Elucidation of species relationships: potential extent of
outcrossing and hybridisation in the species group.
The rising field of molecular genetics provides a powerful means
to address key paradigms of population ecology and gene flow -
including seed dispersal, population connectivity and environmental
adaptations - in an evolutionary context. In particular,
application of hypervariable markers such as microsatellites, in
concert with basic biological data and novel statistical
frameworks, is facilitating new insight into processes underlying
plant spatial distributions from local to landscape scales.
I aim to utilise this emergent field of research and integrate
genetic, ecological and spatial information to identify population
demographic processes in riparian Melaleuca . My research
strategy thus incorporates three key approaches:
- Genetic: Use extant microsatellite markers to genotype
individual leaf samples, and spatial autocorrelation analyses to
identify spatial genetic patterns of variability
- Ecological: Conduct seed bank and seedling cropping experiments
for insight into biological recruitment strategies
- Statistical: Conduct multivariate analyses of genetic,
ecological and spatial data sets; perform and compare range of
current spatial analyses (e.g. Bayesian methods), and consequent
ecological interpretations of spatial genetic and biological
patterns.
Dr Michelle Waycott, JCU
Will Edwards, JCU
Professor Richard Pearson, JCU
Gethin Morgan (EPA, Qld)
