A few Sunday’s ago, just after Victoria declared a Covid-19 State of Emergency stipulating physical distancing measures (among other things), 25 walkers gathered to take in some of the sights, smells and sounds of a little known part of Mt Wombat in the Strathbogie Ranges. Everyone was conscious of the need to reduce risk of infection, but few would have thought it was perhaps the last community activity they’d participate in for many months.
Mt Wombat is a relatively small reserve, but is one of the most popular natural places in the Strathbogie Ranges. Most people simply drive to the top for the spectacular 360 degree view, but leave the road and the tracks behind and there are gems to be discovered. A previous community walk went to the top of Little Mount Wombat, on this walk we went to the bottom.
The weather was clear and intermittently sunny, though a cold wind blew strong on exposed sites. But once in the deep gully, the wind calmed and the trees grew suddenly tall. And up there, in the top of a big Messmate … an eagle nest in ‘the tree that holds the sky aloft’!
The last leg of the walk took us to a spectacular, hidden fairy-land of shadows, wet, spongy earth, ferns, mosses and liverworts. It was the ‘dark, womb of the world’, as advertised. The dominant plant in the wetland was the Soft Tree Fern (Dicksonia antarcita), but perhaps more interesting were the significant numbers of Austral King-fern (Todea barbara), a species not often encountered in the Strathbogies. Most amazing was the size that many of the King-ferns had grown to, with trunks greater than 1 m in diameter and over 1 m high. How ancient are such specimens and how precious?
Having discovered and explored this small, extraordinary wetland, it became clear that it was experiencing several threats. An invasive plant, Tree of Heaven (Ailanthus altissima), has become established in a lower section of the wetland and will require removal. Sambar Deer regularly visit the site and have created large wallows. Perhaps most alarmingly, a 2015 planned burn burnt right around and into the wetland, seriously damaging tree ferns and many of the Austral King-ferns – some are struggling to recover. Many of the King Ferns show signs of having been completely burnt by the planned burn and are now beginning to recover – though not all of them. The planned burn also weakened surrounding Messmate and Victorian Blue Gum trees which, by collapsing into the wetland, have opened the canopy, further drying and stressing the wetland.
Thanks to the knowledge and advice of botanist Doug Frood, we can add a little more to this story. The wetland falls into the vegetation category Fern Swamp (EVC 721), which was not recorded for the Highlands Northern Fall Bioregion by Frood and Papas (2016), but is assessed as Endangered to Vulnerable elsewhere across its range. This document also mentions the vulnerability of this wetland type to hot fires.
This little wetland needs careful management – fire is a direct threat to its survival. Such impressively sized Austral King-ferns in healthy wetlands are rare and special natural environments. The on-going issue now is how to protect such a site from future fires, planned or otherwise. This task is made more difficult because the wetland is now surrounded by a sea of 2 m high Dogwood (Cassinia aculeata) stimulated by the burn. So, by attempting to reduce fuel-load, the planned burn has initiated a large-scale germination event of Dogwood – a relatively short-lived plant which is promoted by disturbance, like fire.
Interestingly, wherever the fire burnt, Dogwood dominates; where the fire didn’t burn it’s an open grassy setting with occasional patches of Dogwood and Austral Bracken. One wonders whether the planned burn has reduced the fire risk, or instead increased it by stimulating all this new growth?
Thanks to Sim for scouting and leading this walk. It was conducted as part of the Strathbogie Ranges CMN‘s Strathbogie Forest Citizen Science; the project and was supported by the Victorian Government.