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The Wimmera Mallee Ecosystem Function Project

You may scroll down the page to read about this project, or use the links below to jump straight to a particular heading.

What is the Wimmera Mallee Ecosystem Function Project?
Activities in 2007
Key findings to date
What is ecosystem function?
What are ecosystem services?
For further information

What is the Wimmera Mallee Ecosystem Function Project? 

BCG, in collaboration with Arthur Rylah Institute for Environmental Research (ARI) and CSIRO Sustainable Ecosystems (CSE), undertook the Wimmera Mallee Ecosystem Function Project which was aimed at understanding and improving ecosystem function in the Murray Mallee and Wimmera bioregions.

The project, through applied research, developed new knowledge about ecological and landscape function and the provision of ecosystem services in the region. The project developed best-bet options for landscape regeneration, practical management guidelines and a monitoring framework that assesses the impact of the restoration options and direct future improvements.

The degraded and fragmented state of natural ecosystems in the Wimmera Mallee region, and resultant threatening processes such as rising regional groundwater, erosion, accelerated climate change and weed invasions, have attracted considerable investment of public funds in efforts to stabilise or reverse these trends.

The project was funded through the North Central, Wimmera and Mallee Catchment Management Authorities and the Department of Primary Industries 'Our Rural Landscapes' initiative.

Activities in 2007

The major survey in 2005 lead to important questions that the project is continuing to investigate. The project team investigated the natural recovery of key ecological functions, such as perennial cover and the recruitment of trees and shrubs in remnant vegetation that has not been grazed for a known period of time. Given that the smaller remnants are typically degraded, what ability do they have to recover if given the opportunity?

In 2007, a limited number of demonstration sites have been established. The sites will trial a number of treatments to improve regeneration success and also be used for practical demonstration of suggested native vegetation management techniques.

Workshops with retired CSIRO researcher, David Tongway, were held in March and April 2007 for facilitators and landholders in Landscape Function Analysis. David developed the technique that enables participants to "read" landscapes for signs of degradation and repair, and collect simple data for monitoring the recovery of sites over time. Read about the workshop.

David Duncan et al. published an article in the 2006 BCG Crop and Pasture Production Manual titled Improving ecological function in our remnants (pdf).

Key findings

The project commenced in April 2005 with the steering committee directing the operational and scientific aspects of the project. A literature review covering landscape, land use history and vegetation history of the region was completed in May 2005.

Field surveys

Survey team in bushland reserve conducting field survey. Field surveys, conducted by ARI ecologists in July and August 2005, provided a landscape overview of ecosystem function in remnant vegetation. Rapid site assessments included soil nutrient analysis, Landscape Function Analysis, and composition, cover and structure of vegetation.

For more information:

• www.cse.csiro.au/research/efa/
• www.deh.gov.au/biodiversity/toolbox/templates/pubs/habitat-hectares.pdf

The report for the first year of field work highlighted some significant findings that will be subject to further investigation. The field work to date has shown that farmers can maximise the opportunities for natural regeneration in their remnants by ensuring that basic ecological function is maintained. Remnant management actions could include:

• Allowing woody debris, soil crusts and perennial vegetation cover to increase, to retain resources and protect the soil
• Reducing grazing pressure to allow native plants to set seed and grow beyond browsing height
• Providing a buffer on the windward edges with new plantings of local natives.

The report also suggests that:

• Regeneration may be more likely to succeed on the leeward edge of larger patches, due to the greater shelter provided
• Planting out alternative stock shelter areas may be a forward-looking solution to reduce the degrading influence of stock on ecological function of remnants

An ARI team member conducting a transect survey in a remnant near Birchip. It is not practical nor desirable to many farmers to have all remnant native vegetation on their properties managed to maximise biodiversity. The reports findings suggest that without management changes, functions such as stock shelters may be lost once the current trees begin to die out if remnants are not allowed any opportunity to regenerate.

The second year of field work, conducted in late 2006, focused on the potential of remnants to respond to stock exclusion. The majority of smaller remnants in the study were primarily valued by landholders as stock shelters and the project team were keen to know if stock were excluded from these remnants what was their potential to respond and recover once the grazing pressure had been removed. To gain a better understanding of the history of the remnants and the past grazing regime landholders were interviewed.

Read the report 'Effect of stock removal on woodlands in the Murray Mallee and Wimmera Bioregions of Victoria' (pdf).
(Please note this document is 37 pages long and may take some time to download)

View Fact Sheet 3. The fact sheet covers:

• 1st and 2nd year of field work
• Key findings to date (remnant size, grazing pressure, nutrient levels, edge effect)
• Take home messages
• Where to from here?

View Fact Sheet 4. The project's final fact sheet covers the key messages to come from the project and introduces The Glovebox Guide (available from the BCG office).

The Glovebox Guide to Understanding and Improving Ecosystem Function is an easy to use guide that is designed to help farmers and land managers understand their patch of native vegetation. The guide can assist farmers and land managers track the health and function of their remnant vegetation and revegetation projects.

A landscape overview

Aerial photographs and general historical descriptions suggest that the landscape surrounding the remnants surveyed were largely cleared prior to 1945 and the period between 1945 and 1990 saw a general increase in the area cultivated. Click on the maps below to view a larger image.

Remnant size was found to influence ecological function - the bigger the remnant the greater the ecological function. Larger remnants have an interior which is relatively protected from degrading influences such as nutrients and weeds whereas smaller remnants are entirely subject to edge effect (particularly windward sides), increased weed invasion and nutrient enrichment. Small patches were found to make up ¼ of all remaining vegetation in the landscape and although heavily degraded they contribute collectively to landscape vegetation cover.

Nutrient levels were highest in small remnants and heavily grazed remnants, levels are often as high as the surrounding paddock or crop, indicating substantial nutrient enrichment due to fertiliser drift and sheep manure. The windward edges appear to be more exposed to nutrient run off, weed invasion and wind effects with the primary cause of the increase in nutrient levels being stock manure.

Edge effect is seen to be greater on windward edges due to the strong SW – NW winds in our landscape. The edge of the remnant is at greater risk of degradation from adjacent land uses resulting in higher weed cover and lower diversity of mosses, lichens and soil crusts.

Remnants with high grazing pressure were found to have an increase in soil phosphorus, weed cover and bare ground while remnants with low grazing pressure have higher diversity and greater cover of native species. The frequency of grazing in the rotation cycle is seen to be too frequent to allow natural regeneration of most long lived perennial species, such as Eucalypts, Acacias, native pine and buloke with a shift towards more annual species. Tree recruitment only occurred in remnants in Alluvial Plains that were not grazed, no recruitment was observed in remnants in Calcareous Dunes.

Read the Landscape Overview Report (pdf).
(Please note this document is 122 pages long and may take some time to download)

What is ecosystem function? 

Within healthy, self-sustaining ecosystems, critical processes or functions are naturally regulated. These processes include soil formation and stabilisation, nutrient cycling, water infiltration and holding capacity, as well as pollination and seed production. In comparison, simplified agricultural landscapes, often require increasing inputs, ie. fertilisers and pesticides, to maintain a given level of function.

What are ecosystem services?

These are the 'products' created by living organisms as they interact with their environment. They provide the conditions and processes that sustain life - the purification of air and water, decomposition of waste, pollination of food plants, regulation of climate and pest control among others.

In July 2005, a workshop involving farmers, natural resource managers and local community members compiled an inventory of the full range of ecosystem services in the Wimmera Mallee. They identified the following as highly valued ecosystem services:

1. Biodiversity conservation through habitat provision and maintenance
2. Conservation of soil health
3. Control of in-stream water quality
4. Moderation of paddock climate
5. Moderation of regional climate
6. Reduction of soil salinity and water tables
7. Mitigation of pollution
8. Pollination
9. Pest control
10. Provision of recreational, spiritual and aesthetic opportunities
11. Enhancement of land value
12. Maintenance of ecosystem resilience
13. Production of minerals, crops, pastures and firewood.

These services fall into three broad types:

1. Services that are inputs into production of goods including food and fibre
2. Regenerative services that maintain natural assets
3. Assimilations of by-products from production of goods.

The CSIRO report (Read the report), a product of the workshop, describes how native vegetation, a key natural asset, contributes to these highly valued services in the Wimmera Mallee. One of the services most at risk is the maintenance and regeneration of native vegetation - a critical though often ignored class of ecosystem services. Too often, services that provide inputs to the provision of goods such as food and fibre are the sole focus of attention. Many regenerative services have either been lost or are greatly impaired in the Wimmera Mallee.

The Ecosystem Services Inventory Workshop, held in Birchip, July 2005.

Valuing the full complement of ecosystems services and benefits is an important means of understanding how native vegetation supports, directly and indirectly, so many valued services in the region.

View Fact Sheet 2. The fact sheet covers:

• What are ecosystem services?
• Why are ecosystem services important?
• What are we doing about it?
• Who is involved?

 

For further information

For further information about the project, please contact Jodie Odgers, Project Officer, BCG 03 5492 2787 or email.