ILWS - Charles Sturt University
ILWS - Charles Sturt University

River red gum floristics and vegetation monitoring (2017 -2018)

Funding

NSW Office of Environment & Heritage, $186,471

Investigators/researchers

Associate Professor Peter Spooner (project leader)

Research Theme(s)

Biodiversity Conservation

Description

The Murray Valley National Park, gazetted in 2010, is located east of Mathoura NSW, on the Edwards and Murray Rivers. The park contains a rich and diverse flora and fauna, where stands of River red gum (Eucalyptus camaldulensis) forests dominate. Of concern are areas of high tree stem densities, where River red gums have densely regenerated following changes in disturbance regimes. As a result, the NSW Office of Environment & Heritage (Science Division) has implemented an ecological thinning experiment, with an aim to determine if tree thinning can deliver improved conservation outcomes in dense stands.

It is hypothesised that reduced densities of River red gums is likely to prevent further declines in the condition of the Red gum canopy.  By lowering competition, it is envisaged that in the long-term, tree thinning will fast-forward the process for remaining trees to become larger, and provide more tree hollows and other resources vital for fauna habitat. Given ongoing river regulation and the likelihood of future droughts resulting from climate change, NSW OEH’s experimental monitoring plan is designed to include river flooding as an experimental factor. The five year monitoring program is led by Dr Emma Gorrod, and will continue until 2022.

ILWS provided significant support for the floristic and vegetation monitoring component of program in 2012 (Floristic surveys in River Red Gum forests project) and in 2015/16 (Floristic monitoring for ecological thinning trial in River Red Gum forests) by providing base-line data (Report) prior to the ecological thinning treatments of experimental plots.

Vegetation monitoring re-commenced in September 2017, after the thinning treatments were completed in June of that year. A team of botanists and ecologists were employed by the ILWS to complete the 2017/18 surveys: Shona Arber, Gavin Thomas, Ché Parker, Josh Howard, Renee Woodward and Peter Worsnop. Team leaders for various stages of the fieldwork were Craig Dunne and Dr Sophie Palfi.  The team measured vegetation floristic and structural attributes in a total of 198 plots scattered throughout the national park. Previous surveys have recorded a total of 101 plant taxa in the park, where in 2015, a threatened plant species was first identified (Floating swamp wallaby grass; Amphibromus fluitans).

Renee Woodward, who carried out plant identification work in the CSU herbarium at the Albury campus, is undertaking an honours research project (Principal supervisor A/Prof Peter Spooner and co-supervisor Dr Emma Gorrod) to investigate the short effects of ecological thinning and flooding on River Red Gum recruitment and understorey vegetation. This research is supported by scholarship grants from NSW OEH and Biosis.

Outcomes

The floristic and vegetation surveys are providing important field data/evidence for the ecological thinning trial, the results of which will advise and inform future management actions in the park.

Contact:

Associate Professor Peter Spooner email
CSU Albury-Wodonga

May 2018