One of the most rewarding things about being an ecologist is the time you get to spend with Nature. As a research ecologist, those times don’t happen as often as you would like – we now spend more time at a computer, reading theory and background, analysing data, writing papers and applying for grants to do more research. However, doing field work gives you the chance to experience magnificent ecosystems, landscapes and wildlife that you might not have seen as a tourist. Those experiences, however fleeting, make the data analysis and administrative headaches all the more bearable!
My recent field work, collecting data for my PhD thesis, was in Victoria’s Murray Mallee (rhymes with ‘Sally’). The mallee is an ecologist’s paradise – full of ecological and geological wonders, and brimming with historical lessons that can guide our future. It is a Mediterranean biome, similar to the French garrigue or South African fynbos, and is one of Australia’s most enigmatically beautiful ecosystems. It’s kind of an ecological transition zone from the coastal plains and ranges of southern Australia, just before you get to the real desert in the heart of the continent.
There are three ‘official’ mallee regions – the southern part of Western Australia; much of South Australia; and Victoria’s north-west – but you will also find isolated pockets of mallee ecosystems through western New South Wales and Queensland. The most distinctive features are the rusty-red sand dunes and the eucalypt trees that grow in a unique multi-trunked ‘mallee’ form.
Driving through the mallee without stopping, you could easily think it was monotonous, dry and drab. But if you find yourself in the midst of the mallee dunes, life is plentiful, from tiny insects and magnificent wildflowers, to emus and red kangaroos. In Hattah-Kulkyne National Park, about 60 km south of Mildura, the Ramsar-listed Hattah Lakes teem with birds most of the year and provide critical holiday habitat for many migratory species. The lakes are anabranches of the Murray River and their lush wetlands shimmer in contrast against the red and gold of the mallee dunes rolling down into the lakes.
Unfortunately, like so many beautiful ecosystems, the mallee has a long record of use and abuse. The region sits in the Murray Darling Basin, which, as a whole, is now suffering ecologically from decades of over use. Clearing in the Victorian mallee started around the 1920s, as returned soldiers and other settlers came to scratch out a living from the newly-gazetted lands.
A 1928 article in the Melbourne newspaper The Argus told how the “monotony of mallee scrub” was an inconvenient wilderness that needed to be conquered in the “war for the safety of democracy – mankind…vindicating his right to occupy the strongholds of Nature.” Pretty strong words to describe an innocent woodland! Acres of virgin mallee woodland were burned and uprooted, and although the ecological and spiritual value of this habitat was realised many decades later, the regrown mallee still bears the scars of this battle.
Of course, human nature has a habit of forgetting the lessons of the past, and now the battle is over water, something which is already in short supply in the semi-arid, fire-prone mallee. Along the border between Victoria and New South Wales, the vastness of the dry mallee dunes are broken briefly by cracking grey clays and regal river red gum forests on the Murray River floodplains – a thin strip of oasis that feeds the landscape for miles on either side.
To a casual observer, standing on the banks of the mighty Murray reveals little sign of exploitation. The water glides by serenely, carrying its secrets like any other wild river. Yet closer inspection reveals the bare height of the eroded banks and the enormous tangles of exposed tree roots. Further into the interior, there is more evidence, where salt has leached through the surface from mismanagement, killing off plants and creating hostile patches of red, crusted earth.
Irrigated agriculture dominates the region, and the majority of Australia’s almonds, oranges and table grapes are produced here, all reliant on the lifeblood of Murray water. The future of this region, which supports a huge number of families, communities and industries, is intertwined with the ecological future of the river and the mallee landscape. Without the Murray, or the mallee, these communities will die. So it’s important for farmers to know how they can support and maintain the beneficial ecological interactions already happening in and around their farms – this will reduce costs to both the farmers and the ecosystem around them.
For example, almond plantations are a key land use in the Murray Mallee, and have rapidly expanded across the region in recent decades. Although the plantations are breathtakingly beautiful for a few weeks every year during flowering, they are eerily barren for much of the rest of it. The wildlife that use the plantations are mostly found around the edges, where the more permanent and diverse resources of the mallee are just over the fence. Most plantations are a couple of thousand acres of nothing but almond trees, and deep in the heart of them you’d be hard-pressed to find signs of life.
Almonds depend on pollination by insects to produce fruit, and growers rely on rented commercial honeybee hives, costing millions of dollars every year. Very little is known about potential wild pollinators that are already living in the mallee – so knowing where these pollinators are around the plantations, and what sort of conditions and resources they might prefer, can help growers to manage plantations in a way that encourages pollinators to visit, and maybe even stay around.
Although there is always more than just one single factor behind the ecological interactions we see, one of our studies found a possible link between the presence of diverse ground cover plants in orchards and a higher abundance and richness of pollinator insects. This could have far-reaching benefits beyond the insects visiting almond flowers – ground cover can also prevent erosion and reduce moisture loss, which might allow growers to reduce their water withdrawals from the Murray, thereby reducing costs and taking pressure off the already depleted ecosystem.
Finding ways to deal with these complex issues is the goal of research. We will never beat Nature, and we will never contain her. But understanding how she works allows us to slot ourselves into ecosystems in a way that can benefit from the abundant resources she holds, without disrupting the essential ecological interactions that provide those resources. Those brief moments we get to escape our desk and administrative headaches are absolutely priceless, for we will never understand how Nature works without spending time inside the ecosystems around us, watching silently as the wheels and cogs of Nature turn around us.
© Manu Saunders 2013