The Mulligans Flat - Goorooyarroo Woodland Experiment

Why was the Mulligans Flat - Goorooyarroo Woodland Experiment set up?

Long-term ecological research is recognised globally as critical for understanding environmental change. However, in Australia, there has been a lack of long-term ecological studies, with few running more than 25 years and none of those having replicated plots from different experimental treatments. There is a critical need for long-term experiments in ecological restoration to inform conservation decision-making, particularly in highly modified or endangered ecosystem types.

A highly modified endangered ecosystem

Temperate woodlands are an example of a highly modified endangered ecosystem.
Yellow box – Blakely’s red gum grassy woodland are a critically endangered type of temperate woodland. A range of human-induced disturbances have led to a drastic reduction in the extent and condition of temperate woodland ecosystems. These threatening processes include:

Project Aims

The need to conserve remaining areas of native temperate woodland is clear, and there is a general consensus about the need for remaining stands of woodlands to be actively managed to maintain and improve their condition.

This project aims to understand ways of restoring the structure and function of temperate woodlands to increase biodiversity. In establishing a designed restoration experiment, our intention is for it to become a long-term ecological research site and an ‘outdoor laboratory’ for ecological restoration research, and community and student learning.

The Site

The study area is in north-eastern ACT, and comprises two adjacent nature reserves - Mulligans Flat and Goorooyarroo Nature Reserves. An area totaling 1146ha of yellow box - Blakey's red gum grassy woodland. This is the largest and most intact example of its type in the ACT.

Experimental Design

The vegetation in Mulligans Flat and Goorooyarroo Woodland Reserves has been mapped by ACT Government staff. Based on this the reserves were divided up into polygons comprising of homogeneous vegetation areas. Using this data, four vegetation classes were identified:

Six polygons within each vegetation class were selected, giving a total of 24 'polygons'.Twelve polygons are in Mulligans Flat and 12 polygons are in Goorooyarroo. Within each polygon, four 1ha “plots” (200m x 50m) were selected, giving a total of 96 plots.

Treatments

A set of key ecosystem manipulations have been chosen to investigate how to reverse the decline in the biodiversity of these woodlands. These are:

• additional coarse woody debris
• kangaroo exclusion
• fire
• reintroduction of Eastern Bettong

In Mulligan's Flat feral pest species (cats, foxes dogs, rabbits and hares) have been excluded since June 2009, with a feral animal-proof fence. This will allow future research on the reintroduction of lost species, like the Eastern Bettong, Brown Treecreeper and New Holland Mouse.

Response Variables

A range of response variables and associated aspects have been chosen to examine the effects of the experimental manipulations on the structure, composition, ecological processes and biodiversity in the reserves. These are shown in the figure below:

1. Coarse Woody Debris
2. Bird
3. Invertebrates
4. Vegetation
5. Reptile
6. Fungi
7. Bettong Reintroduction
8. Brown Treecreeper Reintroduction
9. Kangaroo
10. Small Mammals
11. Litter, soils and soil microbes
12. Exclusion of feral pests

Further Reading

• Manning, A. D., Wood, J. T., Cunningham, R. B., McIntyre, S., Shorthouse, D. J., Gordon, I. J. and Lindenmayer, D. B. Integrating research and restoration: the establishment of a long-term woodland experiment in south-eastern Australia. Australian Zoologist,35(3), 633-648.

• Shorthouse, D.J., Iglesias, D., Jeffress, S., Lane, S., Mills, P., Woodbridge, G., McIntyre, S., Manning, A.D., (2012). The ‘making of’ the Mulligans Flat – Goorooyarroo experimental restoration project. Ecological Management Restoration, 13, 112–125.