Mt Rogers update - December 2010

The extraordinary spring has made way for a wet beginning to summer and an almost tropical humidity. Throughout the region we’ve seen wildflower species responding to the rain and recharged soil-moisture in numbers and a diversity not seen for a decade. 

Summer is attempting to impose its conditions on Mt Rogers now, with the soil damper than it’s been for decades. For days, if not weeks, after the ‘last’ rain, water has been moving downhill and emerging from ‘secret’ soaks and ‘springs’.

 

The path shows, in several places, the layers of previous paths and the underlying rock. Let’s hope the dampness and the need for rain-gear didn’t deter families from taking lessons in erosion, the power of water and the probable drainage patterns of the ridge that is Mt Rogers. Water moving north could end up reaching Ginninderra Creek via the Gooromon ponds tributary and south-flowing water reaches Ginninderra Creek by flowing ‘under’ the suburb of Flynn. Several properties that I know of seem to ‘leak’ water when it rains with shrubs and a huge Photinia between us and our neighbours always seeming to flourish regardless of drought. I’ve assumed that their success and the ‘leaks’ are evidence that natural drainage patterns can’t always be tamed by engineers’ planning and obliterated by bulldozers when suburbs are created. The creek has had historic levels of water passing along it as a result of inflows from as far away as Gungahlin as well as the many localised creeks and drains. (The levels of plastic, general rubbish weeds and natural debris were also high but that phenomenon and a levy on recyclable containers are other stories!)

Most plants have responded to the rain with exceptional growth in our gardens, locally and regionally. The small plants that the Guides planted in August not far from the main car-park are doing very well. Native plant species have emerged from drought-induced hesitation or dormancy appearing in places that have seemed weedy or degraded for decades as well as in biodiverse habitats.

We held a working-bee on 14^th November with Ann and Sue helping to develop a technique of Flatweed and Cat-sear removal from the grassy woodland north-east of Rechner Place’s playground. Whilst this might seem a trivial way to use volunteers’ labour this area is relatively free of invasive species, hosting natives such as Blue grass lilies, Love creeper and Barbed wire grass in addition to numerous Early Nancy and common but attractive spring flowers. As we pulled the weeds from the soft ground, cutting-off and bagging the flower-heads we were hard-pressed not to step on Onion orchids. They have appeared in thousands in the region in recent months, even in quite degraded-seeming grassland. Last year I thought it was pretty special to have found one or two because they were the only ground orchids I’d ever found up there. Being green they’re easily overlooked amongst the other greens of spring.

The trigger for suggesting this weeding was finding three plants of native violet, Viola betonicifolia if you wish to look it up, in the lee of large boulders. When I spotted the first one it was in full flower, its purple-blue blooms highlighted by a shaft of sunlight. It seems the species has appeared in many places in response to conditions but it’s especially cheering to find that Mt Rogers has a small population. That’s another ‘new’ species for our Mt Rogers list.



It’s fascinating to ponder how long corms, bulbs and tubers will ‘wait’ underground for the right conditions. Perhaps the seed banks of some species have been depleted by the mass germination. Will all 2010’s seeds be fertile and survive being eaten by insects, birds and other animals? How many will find the right soil conditions and fungal partners and germinate in the future? If we were able to harvest & destroy all the weeds’ seeds would we be able to rid our Landcare sites and gardens of these pest for ever!

Obviously, for new species we are finding now, it’s a long time for seeds to have remained viable in the soil after the scouring and re-shaping that saw the suburbs developed in the seventies so perhaps the seeds were carried in by visiting birds. Have the orchids “tubers” or “corms” been present in the soil over that same period or have their minute seeds blown in? The lone Sun orchid had 19 flower buds when I last saw it. How did it arrive on Mt Rogers? Orchid seeds are minute and they each need the presence of a specific fungus before they will germinate.         

Early in November the Friends of Grasslands (FOG) organised a photographic workshop in Mulligans Flat Nature Reserve. The aim was that participants would enhance their skills under the sympathetic and expert eyes of professional photographers. The native grasslands revealed a richness of buttercups, milkmaids, bluebells, daisies and lilies, as well as native grasses, for our digital lenses. Hand-lenses had plenty of use also seeking the often-exquisite detail of low-growing flowers. 

In the former sheep paddocks to the west of Mulligans Flat the land has been scoured, graded and reshaped into the suburb of Bonner. Will the new residents, mortgage-laden, ever have time to learn about the species in the neighbouring nature reserve? By late October and after rain, Mulligans Flat provides a wonderful display of natural temperate grassland flowers. The grassland ecosystem is endangered because they were so easily farmed and built on. Our existing grasslands show us what Mt Rogers’ grassy areas would have looked like and that re-planting in the treeless areas isn’t necessarily the “right thing”.

   

There are rich grasslands now surrounded by Dunlop’s streets, and Mt Rogers’ open space probably remains because, at the time, it was uneconomical to build or pump water to houses on the highest ground. Mansions creep up the hillsides of Tuggeranong’s valley and the ex-pine forest land and vistas beyond Weston Creek won’t last much longer or contribute the breathing-space of open space in the lower Molonglo Valley.

The incredible diversity of natural temperate grasslands has inspired and amazed many this spring. Grasslands and woody grasslands such as Mt Rogers are, to our region, what rainforests are to those living further north.

Although the patterns of birds’ breeding vary from year to year the effects of the increased rainfall have fascinated local birdwatchers. Some species which have come to the ACT region for our style-of-summers seem to have stayed away or nested elsewhere.

Larger numbers of Superb parrots than usual remained to over-winter here. There were quite a few extra sightings and then a quiet period before now. Presumably the birds were nesting in or near Mulligans Flat and Goorooyaroo and the young are now strong enough to join their parents foraging further afield. Numbers around the northern and western edges of Mt Rogers have increased in the last 2-3 weeks. This may show that other groups have flown here from breeding areas deeper in NSW.

In mid-Flynn there seems to be a roosting area. The parrots’ calls begin soon after the raucous, daily fly-past of Sulphur crested cockatoos. The Superbs have been enjoying loquats and obviously remember where the trees are from year to year. Un-harvested fruit supplements their diet of Acacia pods and grass seeds.

Finally, let's not forget the weeds! As we all know from our own gardens, the rain has benefited the weeds as well as our desirable plants. Perhaps the daunting task of restoring order has overwhelmed you but there is much fascination surrounding the behaviour of weeds, and trying to identify newcomers.

Rosemary