OUTING REPORT - Geham area, Sunday 04 October 2015

This outing followed on from Dougal Johnston’s informative talk the previous Friday, when he introduced members to local endangered Regional Ecosystem RE 12.5.6.  This cryptic code is easily cracked: 12 refers to the Bioregion (Southeast Queensland); 5 refers to the Land Zone (old loamy and sandy plains and plateaus); and 6 to the Vegetation (too much to include, but concentrates mainly on type of tree cover). For those who would like to read and understand more on Regional Ecosystems, the Queensland Government website:  www.environment.ehp.qld.gov.au/regional-ecosystems/ provides a basic description of these ecosystems across Queensland.

A lengthy introduction, but the writer needed a little background knowledge.  The outing commenced at 8.30 am when twenty-two Nats assembled close to the old Mt Luke Siding on Aberdein Road, Geham. This area and Dougal’s property, were selected to show examples of some of the vegetation typical of R.E. 12.5.6: Eucalyptus propinqua (Grey Gum), E. Microcorys (Tallowwood), E. Acmenoides (Yellow stringybark), E. Siderophloia (Northern Grey Ironbark), E. Pilulris (Blackbutt). 

Close--up of Black Bootlace Orchid (Photo: Mike Ford)

Black Bootlace Orchid (Photo: M Ford)

A short walk along Aberdein Road, guided by Dougal, was followed by a scramble through the Geham National Park. Formerly the Geham Forest Reserve Scientific Area, the Park was declared in 2006, and would appear to have received little or no attention as it is infested with Lantana (Lantana camara). A few vines were struggling through the dense growth:  Billardiera scandens (Apple Berry), Cissus hypoglauca (Five-leaved Water Vine), Geitonoplesium cymosum (Scrambling Lily), Hardenbergia violacea (Native sarsaparilla), Pandorea pandorana (Wonga Vine), Stephania japonica var. discolor (Tape Vine). Parsonsia straminea (Monkey Rope Vine), a very vigorous climber, was well established on large trees at the edge of an adjoining private property.  Most trees in the Park were of intermediate size, in contrast to the large, old-growth trees at the edge of private property adjacent to the Park.  These old trees have been seeding the Park and a few small Allocasuarina torolosa  (Forest Oak), Grevillea robusta (Silky Oak), Maytenus bilocularis (Orange Bark), and a Tuckeroo (Cupaniopsis sp.) were identified.  An ‘unusual landform’ in the forest (a lure to pique curiosity) turned out to be a Scrub Turkey mound.  Various grasses, sedges, Lomandra and Dianella grew sparsely on the forest floor. Geham National Park is a sad example of a lost opportunity to support an endangered ecosystem.

The visit to the Geham National Park was followed by morning tea at Hampton, in the rest area of the grounds of the Information Centre. Refreshed and restored the group then made its way to the start of Merritts Creek Road where it inspected a revegetation site established by Main Roads.  It was disappointing to see that several of the saplings had been vandalised.  

Copper beard orchid (Photo: Mike Ford)

Moving on to Dougal’s well-maintained partially re-vegetated paddock, the contrast between his property and the Geham National Park was stark. A small herd of cattle grazes the paddock occasionally to keep grass in check, but don’t appear to have done any damage to emerging trees.  Dougal is planting local native trees to increase and improve an existing corridor, and encourages natural regeneration.  Areas with Lantana (Lantana camara) were cleared about 10 years ago and a variety of indigenous plants have re-established themselves, including Santalum obtusifolium (Sandalwood) a hemi-parasitic tree that obtains some of its water and mineral nutrient requirements from the roots of other plants. Eucalypts as described above (paragraph 2) were present but vines were less evident in the more more open situation, although two species of Clematis were noted. Rainforest species such as Eleodendrum australe var. Australe (Red Olive Plum), Matyenus biloculars (Orange Bark) and Psydrax odorata var. Buxifolia (Stiff Canthium) are becoming established. However, the plants that excited the most interest were the Copper Beard Orchid (Calochilus campestris) and the saprophytic Black Bootlace Orchid (Erythrorchis cassythoides).

Dougal’s property is a fine example of how, with care and dedication, an endangered ecosystem can be supported and encouraged to regenerate. Sadly, such pockets are now small and fragmented. 

The outing ended with lunch at Hampton. Our thanks to Dougal for a meticulously planned and interesting day.

(Report by Deb Ford)

Bird list from the Geham outing

Pheasant Coucal, Laughing Kookaburra, Forest Kingfisher, Galah, Sulphur-crested Cockatoo, Rainbow Lorikeet, White-throated Treecreeper, Variegated Fairy-wren, Superb Fairy-wren, Lewin's Honeyeater, Yellow-faced Honeyeater, Noisy Miner, Noisy Friarbird,  Scarlet Honeyeater, Spotted Pardalote, Striated Pardalote, White-browed Scrubwren, Grey Shrike-thrush, White-throated Gerygone, Eastern Whipbird, Grey Butcherbird, Pied Butcherbird, Australian Magpie, Pied Currawong, Black-faced Cuckoo-shrike, Rufous Whistler, Australasian Figbird, Willie Wagtail, Grey Fantail, Magpie-lark, Torresian Crow, Eastern Yellow Robin

(Compiled by Donalda Rogers)

 

Brown ringlet - Hypocysta metirius (Photo:Diana Ball)

OCTOBER SPEAKER'S REPORT - RE 12.5.6 – our biodiversity region

Last month Clare Gover said “Habitat is what it is all about!” in trying to keep our wild Koalas. However, we need to understand more about how Koalas fit in the ecosystems where they live, and what makes those eco-systems work. Just planting food trees without understanding the soil, soil bacteria, role of organic matter and the insects and fungi in there, as well as the relations between the food trees and the other vegetation in the relevant ecosystems, may not produce the best result. 

Dougal Johnston sees the environment with the eyes of a geologist. His time scales are measured in millions of years; while ours are measured in months and years and maybe decades. The world around us is changing at all time scales, from the housing developments each year around Toowoomba, to the cropping of the Downs over decades, to land clearing over a couple of centuries, and the coming and going of ice ages (and sea level rise) and the movement of continents over millions of years. Maps from 1945 of Highfields and Cabarlah are barely recognisable as the land we saw in 2005 and what of today?  Invasive weeds such as lantana and Chilean needle grass (a weed of national significance) might not have taken such a hold on our environment if it had not been for intensive land clearing for crops and housing. 

Throughout Queensland we can see many types of ecosystems: Mitchell Grasslands to the north-west of Toowoomba, tropical rain forest of North Queensland, and arid lands to our west - with different soils, different rocks, different vegetation, different climates. Such regions have their own distinct flora and fauna. To conserve and sustain our ecosystems and dare one say, to manage them, it is necessary to describe them in detail. We see such descriptions in The Conservation Status of Queensland’s Bioregional Ecosystems (Sattler P. & Williams R. editors, 1999). This was the first comprehensive description of regional ecosystems for Queensland. 

The editors divided the state into 13 regions (mostly on catchment, climate and vegetation/soil similarity). These were then divided by physiographic type and on each type the vegetation based ecosystems numbered. The area of each ecosystem remaining (compared to the estimate of pre-colonial settlement) was used to classify the ecosystems as ‘no concern’, ‘of concern’ and ‘endangered’.

The most prominent local endangered ecosystem, 12.5.6, is, according to Sattler and Williams, tall eucalypt forest of Eucalyptus siderophloia, E. propinqua, E. microcorys and/or E. pilularis with E. saligna or E. grandis (in open forest) along the lateritic flat range tops from Toowoomba to the north (Laterite is a soil and rock type rich in iron and aluminium). Nearly all laterites are of rusty-red coloration, because of the high iron oxide content. They develop by intensive and long-lasting weathering of the underlying parent rock.

Adjacent to the tall forest (mostly on the upper slopes) are tiny pockets of endangered vine scrub (microphyll rainforest).  Franke Scrub is at RE12.8.21.  TFNC are active in the maintenance of this precious remnant scrub.  Dougal emphasised the misuse of fire regimes in 12.5.6. Much too high fire frequency (and clearing for farming which also utilises fire regimes) has massively reduced the tall forest and almost wiped out some of the vine scrub ecosystems from Cunningham's Gap through the Toowoomba area, up to the Bunya Mountains and well north. Hopefully by observation we can learn (like the geologists – the present is the key to the past) how to better manage and conserve the ecosystems around us. 

By Dougal Johnston with additions from Linda Mangubhai