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REPORT
July 20, 2000
info@brec.ozecol.org
http://brec.ozecol.org

SUMMARY OF BREC ECOLOGICAL PROTECTION RECOMMENDATIONS Portion 238 Cornubia Escarpment
Logan City Qld

Written By Dave Gasteen
with Michael Petter


Cornubia Esc  Cornubia Esc

INTRODUCTION Portion 238 comprises Lots 51-59 on RP 86516 (approximately 115 hectares), with diverse and unique range of ecosystems . There are 15 eucalypt species and other plants of regional significance including rare and threatened species such as Cordyline congesta (palm lily), Acacia perangusta (Eprapah wattle), Melaleuca nodosa (prickly paperbark), Gmelina leichardtii (white beech), and Xanthorrhoea macronema (bottlebrush grass tree).

It has remnant and regenerating rainforest in very steep and more sheltered upper catchment gullies of California Creek. The forest has a large number of mature trees and plentiful nesting hollows. It has a healthy population of wildlife including koala, reptiles, echnida, wallaby, gliders, powerful owls, numerous other birds., and interesting range of invertebrates. It forms part of the Cornubia Escarpment and east-west ridge overlooking the northern side of the Logan River floodplain.

This area provides critical core habitat for koalas, macropods and arboreal mammals and forms part of the largest forest linkage from Venman's Bushland National Park. This link connects upland forests and creeks, through a system of ridges to lowland habitats towards California Creek and the Logan River . These linkages also include bushland habitats east of West Mt. Cotton Road. However, nearly all of the forest linkages adjoining Portion 238 remain unprotected in private property, despite providing vital fauna linkages to significant forest complexes in Venman Bushland National Park and Daisy Hill State Forest Park.

The combined forests around the Cornubia Escarpment are an integral part of the larger Koala Coast core area, and are therefore vital for maintaining wildlife in SEQ. This includes other core forest reserves, Daisy Hill State Forest Park, Neville Lawrie Reserve, Venman Bushland National Park, the Mt Cotton forest catchments for Eprapah Creek and Tingalpa Creek.

Cornubia Esc  Cornubia Esc

MANAGEMENT NOTES To assist the effective management of this significant escarpment and catchment boundary, the following ecological factors have been outlined for each management area; brief overview, habitat values and linkages, access, fire management and rehabilitation values.

To avoid misuse or over use recreation, conservation, and education opportunities all need to respect the intricate ecological values, limiting factors and thresholds of this forest .

Overuse or misues can be avoided by discreet placement of access tracks that will avoid wallaby trails, resting and grazing areas, delicate plant ecosystems and steep terrain.

However, for the sustainable management of recreational access in Portion 238 to become a reality, it is critical that the ridgeline forest escarpment must have the same level of protection as Portion 238. This outcome will ensure safe public access and appreciation of outstanding scenic values and ecological perspective of this significant core forest with one of the few upland to lowland forest linkages in Logan City.

It is recommended that a vegetation rehabilitation strategy be implemented with a specific focus on lantana removal from sheltered gullies, to allow rainforest recovery. The major problem with lantana is the complete dominance of the understorey in some areas, restricting its development, but also drastically increasing fuel loading and fire intensity. It is important that lantana is removed in a mosaic of smaller patches that minimise any negative impact on fauna.

Access to each management area

The central ridge track is presently highly erodible owing to the steepness of the terrain and should be partially closed, rehabilitated, and realigned. The major east-west ridgeline track should be upgraded for fire management and emergency fire control access only. Secure fencing and strict control of access from adjoining properties should maintain control of 4 WD and trail bike access.

Other pedestrian track access should be for local users only and based upon safe contour lines, that respect and avoid wildlife sensitive areas and significant plant ecosystems. These will form the basis of the track map and brochure, highlighting the ecological significance of this core forest reserve as well as the best views and lookouts.

Fences and barriers are required to restrict human and machine/horse access, and for protection of wildlife from predators but also allow some access for fauna. In particular exclusion barriers should be placed along West Mt Cotton Road, adjoining Parkview Estate and Kimberley Plateau Estate.

Precautionary Fire Notes

Any proposed fire management needs to be aware of the intimate knowledge required or to be regained of small scale mosaic burning techniques, that allow for a more diverse and distinctive range of vegetation and habitat types.

For this reason, there should be no large scale "controlled burns" that sweep across these forest types, at the expense of discreet gully systems or vegetation types that are more prone to fire damage. It is important that any intended fire strategies recognize that distinctive vegetation types require different fire regimes and intensities, and that these form the basis of fire management.

There needs to be a review of the width and management of fire breaks and creation of fire buffers in surrounding properties. In urban areas the firebreak should be outside of the designated park/forest contribution. Often as a result of their very narrow width the firebreaks suffer from multiple abuse impacts and edge effects such as dumping, weeds, fires, tracks & clearing.

Several ecosystems have been identified as fire sensitive and will suffer from a loss of biodiversity, if there is not proactive intervention of some fire management practices. This includes establishing fire exclusion zones, such as steep slopes and discreet drainage lines with rainforest alliances (Area 2, 3 & 4), forest red gum, swamp box and paperbark alliances within the drainage basin in Area 5.

Exercise manual fuel reduction and other fire prevention techniques for a period of 5-7 years.. This includes fuel reduction and removal, especially lantana, to allow fire sensitive rainforest regeneration, with some back burning from the upper slopes and away from all steep, sheltered gullies.

Protection of Additional Areas

The area surrounding Portion 238 has high natural values, protects the water catchment for the Leslie Harrison Dam and buffers the adjacent national park This ecologically significant Cornubia Escarpment Area needs be formally recognized as a vital part of the protected forest systems of the koala coast.

Priority area for protection is the east-west ridgeline and forests, which comprise the catchment boundary for Venman Creek (north) and Cornubia Creek, a tributary of California Creek (south).

Portion 238 will become a more ecologically functional core forest, if there is tenure security of the northern adjoining forest along the escarpment, with key linkages to Venman Bushland National Park, adjoining private property on West Mt Cotton Road and linkages to core forest reserves along California Creek, the Leolindo Drive ridgeline and into Kimberley Forest Park.

The future planning scheme for the City of Logan, including the Strategic Plan, Vegetation Management Study, require urgent review with the intention of ensuring rural options north of Portion 238 are included as a conservation reserve and not for more rural and/or residential development.

It is essential that these areas are retained intact (and not subject to increased housing pressures of future development), which will reduce threats from dog attack, fire, edge effects (die back of trees on margins and weed invasion).

The state and local governments should investigate these lands for immediate protection as key forest linkages north including

The zoning of other adjacent blocks to Portion 238 should be reinforced by local laws, vegetation preservation and conservation agreements . These blocks form important linkages,range and dispersal opportunities for regionally significant koala, wallaby and glider populations. Other strategies could include revegetation of cleared rural properties and establish a more substantial forest linkage to California Creek.


Summary of Area for further protection from development

East-west ridgeline and catchment boundary

This area has distinctive variations in soils and geology on high ridgelines, with very steep gullies, which have influenced the types of vegetation patterns and dominant floristic structures. These are very distinctive from Portion 238, and include smudgee forests with heath and grass trees, and outstanding open forest with old growth trees, including blackbutts and tallowwood.

It is essential that these forest complexes are secure from development, and reviewed as a matter of urgency by local council and the state government, in accord with the importance of the region (Koala Coast and National Park). This is especially pertinent considering the history of environmental degradation and residential sub-division and clearing in Logan (Kimberley Forest Estates).


Cornubia Esc  Cornubia Esc

RECOMMENDATIONS AND SUMMARIES BY MANAGEMENT AREA

AREA 1 Upper catchment of Cornubia Creek

This area excludes the majority of the ridgeline catchment boundary, although it does have access to the highest area, via an informal track to the "lookout", and is an important catchment of Cornubia Creek, a tributary of California Creek.

There are some spectacular old growth trees and very steep gullies and rocky scree slopes, with several protected drainage lines and tributaries, that perform the critical role of providing continuous forest linkage to the Logan River and diverse wetland ecosystems.

Access Notes: In recognition of the sensitivity of these steep, highly erodible rocky scree slopes, the major access track from West Mt. Cotton Road to the western water reservoir should be closed at the entry points in Portion 238. It is also recognized that this access has been historically used for many purposes, resulting in some degraded and eroded sections from trail bikes, four wheel drive and other vehicles, and horses.

The Conservation A area north of Portion 238 should be excluded from future development pressures, including any road construction, and then any future management of this core area will utilise the east-west access.

Fire Notes: This area needs protection of fire for approximately 5-7 years to allow for natural forest succession and forest layering, with general fire control principles in the interval to be back burning in two directions: 1 - north and south from the ridgelines and 2 - away from the steep dissecting gullies.

Habitat Notes: These upper slopes and adjoining ridgelines are important ecotones for the transfer of genetic material (flora and fauna) from southern regions to the adjoining Conservation A forests and into Venman’s Bushland National Park

These upper slopes and escarpment are highly desirable habitat for a range of gliders, possums, raptors and koalas for dispersal and also macropods. Wallabies must have large forests and connecting habitat for ranging to other dispersal areas. There needs to be North-east forest linkages joining to the eastern side of West Mt. Cotton Road. Linkages to other catchments and to Mt Cotton also need to be secured.

It is clearly evident from research that Mt Cotton Rd is a major killing zone for dispersing wildlife (koalas and wallabies), and that urgent speed limit restrictions be implemented and enforced, as elsewhere in the koala coast, with signage.


AREA 2 South-west catchment of Cornubia Creek

This area has exposed rocky soils on very steep slopes that are easily disturbed and leading to erosion, with a network of sheltered gullies, and some rainforest associations with a long dividing catchment ridgeline separating it from area 3.

The dominant forest types are mixed eucalyptus (spotted gum, stringybark and bloodwood) open forest and low understorey, on the steeper slopes, and brush box, tallowwood, and grey gum in sheltered lower drainage lines.

Access Notes: In recognition of the sensitivity of this ridgeline escarpment and steep, highly erodible rocky scree slopes, there should be no access across this area, but a small track may be possible along the high ridgeline above road end.

Fire Notes: This area needs protection from fire for approximately 5-7 years to allow for natural forest succession and forest layering, with general fire control principles in the interval to be restricted to back burning from the ridgelines and away from the steep dissecting gullies.

Habitat Notes: This area provides an essential buffer to the adjoining housing developments to the west and south, and is therefore an integral component of the upper catchment of Cornubia Creek. There are numerous hollows and nesting sites in termite nests for range of arboreal fauna, and food resources from flowering bloodwood, spotted gum and tallowwood, and herbivores such as greater glider, possum and koala.


AREA 3 Central Catchment and Amphitheatre

Access Notes: The steepness of this area, combined with the fragility of exposed rocky scree slopes, makes any form of access undesirable, and therefore should be restricted. This will ensure the significant ecological attributes and fauna utilisation are not compromised by human overuse.

For this reason, access should focus on linking trails from the lookout in Portion 238, along the escarpment track to the central catchment boundary as an interpretive overview of the outstanding ecological features of the area. However, this will require a conservation agreement or similar security of access through acquisition.

Fire Notes: The steep gully networks and type of forest communities require a fire exclusion zone, to enable forest succession and forest layering to recover. This can be achieved by manual fuel reduction, and burning away from these fire-sensitive areas, and help maintain critical ecotones and forest mosaics.

Habitat Notes: This unique amphitheatre has tall forest of tallowwood, grey gum, brush box and rainforest alliances in the understorey, which provides habitat, range and shelter for many ground and understorey dwelling fauna, including swamp wallaby, echidna, bandicoot, small mammals and flocks of small birds.

These include wrens, white-eyes, honeyeaters, grey fantails, and valuable shelter for eastern whip bird, noisy pitta, flycatcher, spangled drongo, white-browed tree- creeper, eastern yellow robin, rufous whistler and golden whistler.


AREA 4 Eastern Catchment

This area comprises the upper eastern catchment of Cornubia Creek, with the central ridgeline from the escarpment as the dividing catchment for the western area and also providing protection for the lower drainage basin by the steep slopes adjoining West Mt Cotton Road.

Access Notes: There is currently an opportunity for a small trail access through forest to connect with existing track adjacent to the southern boundary. It is possible to utilise this track network to gain access onto the central ridgeline and access to the highest point "lookout", along the east-west escarpment.

However, this track needs upgrading, including closing steep sections, and ensuring track grades follow contour lines, in order to prevent erosion potential from misuse.

Fire Notes: This area needs protection of fire for approximately 5-7 years to allow for natural forest succession and forest layering, with general fire control principles in the interval to comprise back burning in two directions, these are:

1 — from the central ridgeline towards the gully network, and from West Mt Cotton Road and 2 — burning away from the sheltered gullies towards the ridge fires.

The purpose of upgrading the central track will facilitate manual fuel reduction strategies. This will result in minimising the threats posed by fire outbreaks and their severity.

Habitat Notes: This catchment provides excellent habitat and diverse range of ecosystems for fauna as a means of range, dispersal and shelter for wallaby, glider, echidna and koala. This area is an essential sheltered fauna habitat and opportunity to forage safely in the adjoining sheltered lower drainage basin.

These dispersal areas include adjoining forest in Portion 238, northeast forest linkages to Mt Cotton forests, northwestern to Venman’s National Park, and southeast through private properties, remnant forest and riparian forest linkages to the Logan River.


AREA 5 Eastern Catchment gully systems and lower drainage basin

This area has significant and diverse plant and animal habitat and ranges, including wallaby grazing flats on blue gum alluvials with some rainforest regeneration based upon current fire regimes. Other plant alliances include mixed eucalypt, swamp box and paperbark, Melaleuca nodosa (prickly leaved paperbark) dominant understorey with E. seeana, Corymbia intermedia.

Access Notes: This area has an informal local walking track along the southern boundary going east towards the powerline easement, which has moderate use and some evidence of trailbike, horse and animal use.

Fire Notes: This area needs protection from fire for approximately 5-7 years to allow for natural forest succession, rainforest remnant recovery, and also for the protection of the diversity of plant alliances in this catchment.

Concurrently, the dry sclerophyllous forests and heath associations should be maintained by strategic fire regimes, with a focus on ensuring these fires do not alter the composition of plant alliances that are susceptible to fire intensity and frequency.

Habitat Notes: The forest red gum alluvium flats have several large old growth trees that have numerous large branch hollows utilised by gliders, possums, owl and kookaburra. They are the primary food tree for koala and greater glider.

There are also abundant activity by bandicoot and echidna and excellent grazing, resting and dispersal areas for wallabies, as evidenced by flattened grassy areas, trails and numerous scats. This area also provides a buffer and habitat ranges for southern movement of fauna to other connecting forest ecosystems. It also provides linkage to the upper catchment, through northern and eastern forests.


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