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Written by John Bowden
Environment Services Department
Pine Rivers Shire Council
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| Overview |  |
 |  | | Mixed tall open Eucalypt forest. Photo: John Bowden |
Recently, ecosystems in Queensland, and elsewhere in Australia, have been and are being mapped in a way that reflects the geological factors (such as parent rock, soil type, aspect and drainage), these have a great influence on the natural vegetation and, therefore, the fauna in any given place. In the Mountains to Mangroves Corridor, we have identified nine regional ecosystems.
In the basins of valleys where there are granitic rocks, 215 million years (Triassic) and older (such as at Samford and Keppera), near the upper reaches of the creeks of the Corridor the regional ecosystem (R. E.12. 12) is woodland dominated by Queensland Blue Gum and Narrow-leaf Ironbark and sometimes Grey Ironbark. Other trees include: Silver-leaf Ironbark, Moreton Bay Ash, Broad-leaf Gum, Rusty Apple and Pink Bloodwood, with Swamp Paperbark and Swamp Box in moister areas near drainage lines. This ecosystem has been extensively cleared for pastures and only 20% remains. Its conservation status is 'of concern'.
In the wetter and higher areas of the upper catchment and its near west, on deformed and metamorphosed sediments 215 million years (Triassic) and older, the regional ecosystem (R. E. 12. 11. 5) is mixed tall open forest in which Spotted Gum is relatively common. Other tall trees include: Grey Ironbarks, Grey Gums and Stringybarks. Associated trees include Broadleaf Spotted Gum, Bloodwoods, Queensland Blue Gum, Gum-topped Box and Rusty Apple, with Brush Box in the gullies. There is a mixed understorey of grasses, shrubs and ferns. There are occurrences of the rare and threatened species, Broad-leaf Spotted Gum and Sophora (Sophora fraseri). Lower altitude occurrences of this habitat have been extensively cleared and fragmented. With 41% remaining, the conservation status of this regional ecosystem is 'not of concern at present'.
In Bunyaville State Forest, the regional ecosystem (R. E. 12. 11. 19) is open forest of Broad-leaf Ironbark with or without Spotted Gum or Broadleaf Spotted Gum, Narrow-leaf Iron Bark, Gum-topped Box, White Mahogany, Queensland Blue Gum and Rusty Apple, on deformed and metamorphosed sediments 215 million years (Triassic) and older. 61% still remains so the conservation status is 'no concern at present'.
Along streams and larger gullies of the Corridor, the regional ecosystem (R. E. 12. 3.7) is a narrow fringing community of Queensland Blue Gum, Weeping Bottlebrush and River She Oak, with or without Weeping Myrtle. Creek Matt Rush is common along stream banks. Other associated species include River Tea Tree and Snow-in-Summer. It occurs on alluvial plains of sediments of 65 million years to 2 million (Cainozoic). It is being invaded by such introduced weeds as Chinese Elm and Cat's Claw Creeper. 44% remains and the conservation status is 'no concern at present'.
Scattered here and there along streams and on flood plains are small remnants of complex to simple rainforest on Cainozoic alluvial plains. The plants have small to medium sized leaves and include Pepperberries, Brown Laurel, Brown Tulip Oak, Sandpaper Figs, Moreton Bay Fig, Native Elm, Blue Quandong, Silky Oak, Black Bean, and Giant Water Gum with emergent Flooded Gum and Hoop Pine. This is habitat for rare and threatened fauna and flora such as Macadamia species, the Richmond Birdwing Butterfly and Coxen's Fig Parrot. It is also an important food source for fruit-eating birds that migrate seasonally between the mountains and the coast. Much of this ecosystem has been cleared for agriculture and is invaded by weeds such as Camphor Laurel and Cat's Claw Creeper. 23% remains and the conservation status is 'of concern'.
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In Boondall Wetlands and nearby upstream areas there are four regional ecosystems types:
On estuarine deposits of Quaternary age (2 million years or less), the regional ecosystem is Swamp She Oak open forest (R. E. 12. 1. 1), with or without Swamp Paperbark. This ecosystem can extend inland beyond tidal influence. It is subject to weed invasion especially Groundsel. 30% remains and its conservation status is 'of concern'.
On Quaternary estuarine deposits on marine plains and flats subject to tidal influence, the regional ecosystem is saltpan vegetation comprising Marine Couch grassland and samphire herbland (R. E. 12. 1. 2), with Pitted Blue Grass sometimes present in upper portions. 91% remains and the conservation status is 'of no concern at present'.
On Quaternary estuarine deposits subject to daily tidal incursion, the regional ecosystem is mangrove shrubland to low closed forest (R. E. 12. 1. 3). In the Boondall Wetlands there are six species of mangrove, and, along tidal creek banks, Mangrove Fern.
On alluvial plains in coastal areas of Cainozoic age (less than 65 million years), the regional ecosystem is Swamp Paperbark, Queensland Blue Gum, Swamp Box woodland (R. E. 12. 3. 6). 30% remains and its conservation status is 'of concern'.
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| Fresh Water Aquatic | |
Along the creeks and drainage lines in Mountains to Mangroves Corridor is a variety of ecosystems where freshwater is permanent (ponds, pools, lagoons) or ephemeral (soaks, swamps, bogs).
Here is a rich growth of floating plants (duckweeds, and azollas - native floating ferns), submerged plants (hornwort, stoneworts, watermilfoils, etc), emergent plants (aquatic grasses, reeds, rushes and sedges) and associated plants (bottlebrush, black tea tree and river she oak) These supply food for a multitude of animal species.
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Freshwater aquatic invertebrates include the beautiful and active dragonflies and damselflies, caddis flies, orange-clawed yabbies and shrimps. Small native fish, common now only in the upper parts of the Catchment, are rainbowfish, platies, gudgeons, blue-eyes and glass perch. Larger fish, also now less common than in the past, are Spangled Perch, Dewfish and Long-finned Eels.
The Brisbane Short-necked Turtle and the Eastern Long-necked Turtle are the most common of the turtles in the Catchment. Commonly observed reptiles along the streams of the Corridor include the harmless Common Keelback (a snake that eats Cane Toads without ill-effect), the Eastern Water Dragon and the Eastern Water Skink.
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In the less polluted reaches of creeks we may be lucky enough to observe the shy Platypus. Numerous birds that inhabit the Catchment streams have lovely calls. These include Reed Warblers, Brown Honeyeaters, Striated Pardelotes and Mistletoebirds.
Frogs are lovers of moist areas and along the Mountains to Mangrove Corridor we have a rich frog fauna. We have tree frogs, froglets, marsh frogs, pobblebonks, gungans, barred frogs and broodfrogs. These many species provide us with one of the richest and most interesting frog faunas in Australia.
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| Inter Tidal | |
The inter-tidal (littoral) zone of the coast is a rich zone that supports a diverse range of species. An important source of the nutrients that feed the organisms of the ecosystems here is the sediments that travel down the Corridor, especially during floods.
The richest inter-tidal ecosystems are mangrove low woodlands and closed forests. Because of the protection afforded by Moreton and Stradbroke Islands, mangrove trees and shrubs grow along almost the entire coast of the Corridor. Six species occur here: Grey Mangrove, River Mangrove, Red Mangrove, Orange Mangrove, Yellow Mangrove and Milky Mangrove. Mangroves are one of the most productive ecosystems on Earth, with leaves, fruit, twigs, branches and trunks falling to the mud to feed countless species of bacteria and microscopic invertebrates that are food for larger small animals which in turn feed the animals higher up the food chains.
About 70% of the local seafood species that are obtained from Moreton Bay fisheries spend at least part of their lifecycles here - Mud Crabs, prawns, oysters and fish. Some bird species also could not exist without mangroves - Mangrove Gerygone, Mangrove Honeyeater and Collared Kingfisher.
At low tides on the mud flats, a rich supply of invertebrate species, such as segmented worms, flat worms, molluscs and arthropods provide for more than 20 species of migratory wading birds. These feed voraciously to build up enough tissue to enable them fly to breeding grounds as far away as Siberia, Alaska and Japan. As well there are many local sedentary shoreline birds.
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| Wildlife Movement Along the Corridor | |
The animals best able to move along the corridor are those that can fly. Many insects, such as moths and butterflies, can travel long distances in trips seeking food, mates or larval plant species. Others, such as termites, ants, bugs and beetles may move in short flights, but in time these species may cover many kilometres. The real users of the Corridor seasonally are birds and flying foxes.
Some birds may fly high along the creeks from roosting sites to their daily feeding grounds. For example, Cattle Egrets may visit pastures in the west of the Corridor from campsites at Tinchi Tamba Wetlands in the east. Rainbow and Scaly-breasted Lorikeets range out from semi-permanent roosting sites in tall trees to feed on the nectar and pollen of flowering eucalypts, corymbia, melaleucas and callistemons.
In autumn each year, some bird species move from the mountains to the coast and, in late spring, move back to the cool of the higher land. Noisy Pittas spend most of their time in mountain and riparian rainforests to the west of the Corridor, but for the winter, some move down to well-vegetated areas near the coast, and may visit suburban rainforest gardens. Cats are a major problem for these beautiful ground-feeding birds. Other birds that move from the mountains to the coast in the cooler months include Fantails, Monarchs, Yellow Robins, Scarlet Honeyeaters and Currawongs. Some fruit doves and black cockatoos move along the Corridor when food trees are in fruit.
Flying Foxes (Fruit Bats) fly out from their camps on the Pine River and in the Boondall Wetlands, sometimes along the Corridor, to feed on flowers, nectar and fruit. The major species are the Grey-headed Flying Fox and the Black Flying Fox. They are of major importance in pollinating native plants and dispersing their seeds. In this way they assist plants to move along the Corridor.
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