Alpine Peatlands

Alpine peatlands, or ‘bogs’ as they are often termed, can be dismissed as just the wet, soggy, spongey areas you generally see scattered along drainage lines in the mountains. Many hikers would be all too familiar with the feeling of surprise when they misjudge a step and soak both their socks and boots by sinking through the fringes of the peatland. Wet feet aside, there is a lot of delicate beauty in the congregations of highly specialised plants, and beneath the surface there is a hum of activity as these ancient peatlands are hard at work creating the next generation of mountain soils and rivers.

Australia’s alpine mountains are fundamentally different from the jagged rocky peaks of the Himalayas or European Pyrenees. They are rounded with peaks that sometimes blend into the wider plateau so much that it can be difficult to figure out where the true ‘summit’ is. Their unusual shape goes back to their origin. While most mountains across the world emerged from the collision of tectonic plates, the mountains of the Australian Alps are the ancient result of continental splitting, piled with soil from longer erosion periods and a whole lot of peat and humus.

The Australian alps are over 400,000,000 years old, with soils developed over millennia. The rate at which peat develops is painfully slow – a mere 2 mm per year. And yet, in a single night, one Samba deer can destroy over 80 years of soil building progress in one foul swoop.

 Besides creating mountain soil that goes on to form many of Australia’s uniquely rounded mountaintops, alpine peatlands also birth rivers. In Australia, peatlands are fed mainly through underground water. These water storages compromise snowmelt from decades ago – the water that flows into peatlands is, on average, 30 years old by the time it resurfaces to form the headwaters of some of Australia’s longest and most significant rivers.

Alpine peatlands regulate river flow by storing water in large colonies of Sphagnum Moss. They act as slow-release watering systems, allowing these small alpine streams to flow perennially, contributing to more consistent river flows through the upper catchment to provide water all year round. Without peatlands, alpine streams may lose their consistent Summer baseflow, dry out, and become unable to support such a wide range of endemic and iconic species.

While the water itself is approximately 30 years old, it is in its infancy compared to the organic matter found in alpine peatlands. This matter can be up to 8,000 years old and began accumulating soon after Australia’s last glacial event during the Holocene. The peat can entrain pollen particles and charcoal deposits which hold vital information about our past climate. With so much history stored in these peatlands, it is no surprise that so many soil, water and climate scientists flock to alpine peatlands for answers that will help them better understand our changing climate.

Alpine peatlands communities are formed by highly specialised plants that can withstand waterlogging, freezing temperatures, and extended periods under snowpack.  Within each peatland, there is a surprising variety in micro-climates and conditions that can support the full floral spectra from shrubs to herbs, grasses, sedges, rushes, ferns and mosses.

The height of the water table in particular holds significant influence on where each type of species is found. In areas with a high-water table, you’ll find hydrophilic (water loving) plants like mosses, herbs, rushes and sedges that thrive in constant saturation. Conversely, in areas with a lower water table, grasses and shrubs will be in higher abundance, as species that cannot tolerate such prolonged inundation.

In these intricately beautiful ecosystems, there are delicate flowering plants in all pastel shades, aromatic shrubs, as well as edible herbs.

Alpine Daisybush (Olearia algida) and Alpine Baekea (Baeckea gunniana) are commonly found aromatic shrubs with white/cream flowers. Willow Herb (Epilobium gunnianum) blooms in pale pink, while Matted Nertera (Netera granadensis) carpets the ground with pale orange beads. Candle Heath (Richea contenentis) and Coral Heath (Epacris gunnii) will draw your eye from afar, as their florets stand tall above the peatlands with white and cream flowers. Pineapple Grass’ (Astelia alpina) iconic shape often stands out, with green and grey leaves arranged like the head of a pineapple. If you’re lucky, you may even see Alpine Water Ferns (Blechnum penna-marina) with miniature creeping and overlapping fronds of deep green. And if you’re curious about edible plants, you can enjoy the seeds of the Bog Carraway (Oreomyrrhis cilata). This plant grows with little ferny leaves, topped with deep purpley-red seeds that are well worth tasting.

While Sphagnum Moss is the plant most commonly associated with alpine peatlands, the species is not always present in peatlands. The Rope Rush (Empodisma minus) is another heavy lifter, contributing the most organic matter of the peat forming species. Empodisma minus translates to ‘tangle foot’, which will make sense when you see it in the peatlands. The slender rope-like fronds mat together to form a thick knitted carpet beneath the water’s surface as it gradually decomposes into fresh peat.

Alpine peatlands operate on a time scale well beyond humans’ ability to fathom. They survive many thousands of years, working slowly but surely to build new mountain soils and shape rivers. One of the most vulnerable alpine ecosystems, Alpine peatlands hold a disproportionately important role in both water security across South-Eastern Australia and global carbon sequestration.

The largest threats to peatlands are physical damage from hard hoofed animals, intrusion from invasive plant species, and bushfire.

The North East Catchment Management Authority is proud to work in the Victorian Alpine Peatland Protection Coordinating Committee (VAPPCC), comprised of representatives from three Catchment Management Authorities and Parks Victoria. This team has worked for over a decade to undertake and research on-ground works to alleviate stressors in these vital ecological communities, such as deer and weed control.

We are optimistic about our goal of achieving broadscale peatland recovery, assisting alpine peatlands to continue building soils, filtering water, regulating stream flow and supporting a plethora of rare and beautiful species.