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Our research

Find out what we have been working on for the Relict Rainforest and Woodland Conservation Project. 

We visit permanent field plots four times a year between September and April and record the flowering and fruiting stages and rates in plants within these plots. The accumulated data over several years will help to provide an idea of the community health. We are also interested in understanding how climate (temperature and rainfall) affects plant reproduction in these Threatened Ecological Communities (TECs). While in the field, we opportunistically make seed collections of species that occur in the communities for long-term ex situ storage at the NSW Seedbank and for seed biology research.

In amongst semi-evergreen vine thicket vegetation overlooking farming land.
Collecting Cadellia pentastylis (Ooline) seeds.

Our seed testing workflow in the laboratory first involves using a two-way thermogradient plate that allows us to examine germination success across a broad range of constant and alternating temperature effects (typically between 5 and 40°C). Using a newly designed R-stats workflow, we then run our germination results through several statistical models to estimate and quantify the germinability of the seeds across all temperatures. We then use this information to predict when germination might occur for the species in the field under current and future climates. Our method provides valuable information for identifying species that may be at risk of reduced future recruitment rates in the field, thereby helping prioritise management actions.

Cadellia pentastylis (Ooline) and Casuarina cristata (Belah) seeds sown on water agar. 
Capparis mitchellii (Wild Orange) fruits collected in the field.
Capparis mitchellii (Wild Orange) seeds on the two-way thermogradient plate.

Seeds are then tested for their ability to germinate when moisture is limited. To achieve this in the laboratory, we simulate decreased water potential using the polymer polyethylene glycol (PEG). PEG influences the osmotic potential of solutions by binding to water molecules, which are then unable to be absorbed by plant cells. This information is useful when re-seeding ecosystems as it tells us whether we might need to provide extra water to seeds of some species to increase germination success. Following this test, a species is designated as having a ‘very high’, ‘high’ ‘moderate’ or ‘low’ sensitivity to moisture stress.

Acacia harpophylla (Brigalow) mature seeds in open pods on a tree. 
Acacia harpophylla (Brigalow) seedlings emerging in the field following significant flowering in spring 2020.

Tracking our work since 2019

Task Number Outcomes
Plant species recorded in our field plots 223 Monitoring species for flowering and fruiting events.
Seed collections made 51 Collections of multiple populations for 13 species.
Species run on thermogradient plate 10 Seeds of some species germinated over a broad temperature range, while several other species showed a narrow temperature range suitable for germination.
Species tested for moisture stress 7 Most species tested so far have a ‘high’ to ‘moderate’ sensitivity to moisture stress.
Peer-reviewed articles published 1 Knowledge transfer is essential to benefit landholders, policy, community groups, conservation and restoration industries.
See our Latest Publications for more information.
General articles published 1