Proposed Rehabilitation Plan

 

 

General Site Information - Overview

This Riparian Rehabilitation Plan has been prepared to direct the ecological restoration of the
waterway and immediately adjoining riparian zone located in proposed Lot 1 which is to be
created from the subdivision of Lot 46 on RP13461, located at 21 Jirrima Crescent, Cooroibah.

The Rehabilitation Area extends for 10m either side of the high bank of the waterway and covers
a total area of approximately 0.2ha (refer to Plate 1). The Rehabilitation Area is characterised by
dense macrophytes and native herbs at the water’s edge, with a narrow row of existing mature
native trees immediately adjoining the waterway. Plates 2 and 3 depict existing conditions
within the Rehabilitation Area.

The remainder of the area to be rehabilitated is characterised by areas that are currently
regularly mowed. Despite the historical mowing, the Rehabilitation Area contains moderate to
high in-situ ecological resilience, with a diversity of native recruitment already occurring in the
ground stratum (refer to Plates 4 and 5). The dominant limiting factor preventing regeneration
of the waterway corridor is the current intensive mowing regime. Removal of mowing and
selective weed control within the Rehabilitation Area is expected to allow recruitment from the
existing soil stored seed bank and from outside sources. The Rehabilitation strategy prescribed
for the area will predominantly involve assisted natural regeneration as defined in the South
East Queensland Ecological Restoration Framework - Manual (Chenowith LPA, 2012).

The Rehabilitation Area is mapped by the Queensland Herbarium as historically containing the
pre-clearing regional ecosystem RE 12.3.4 which is described as a Melaleuca quinquenervia,
Eucalyptus robusta woodland vegetation community. The existing tree species and native
recruitment within the Rehabilitation Area was observed to be consistent with the pre-clearing
regional ecosystem mapping. The narrow band of trees is dominated by mature Melaleuca
quinquenervia (broad-leaved tea tree), with a small number of Lophostemon suaveolens (swamp
box), Acacia disparrima (hickory wattle) and Eucalyptus racemosa (scribbly gum) also present.
The edge of the waterway is dominated by a dense band of semi-aquatic herbs and macrophyte
species including Persicaria strigosa (prickly smartweed), Leersia hexandra (swamp rice grass),
Bacopa monnieri (Bacopa) and several native sedge species (Cyperus spp.). A small number of
shrub species occur such as Austromyrtus dulcis (midyim berry), Melastoma malabathricum
(blue tongue), Banksia robur (swamp banksia), and Sannantha bidwillii (twiggy myrtle). Several
native herb species also occur in moderate densities within the existing areas of mowed grass.

Several weed species occur within the Rehabilitation Area in generally low densities. Primary
weed control and ongoing maintenance of the Rehabilitation Area is expected to assist in
reducing the potential for weed dominance and over-competition as the native species
composition re-establishes over time.

The existing vegetation within the Rehabilitation Area is expected to provide habitat value for
native fauna species, predominantly wetland birds and amphibians. It is noted that the
surrounding vegetation is mapped as containing koala habitat and that the riparian corridor has
the potential to provide connectivity between adjoining habitats. The species observed to be
recruiting within the proposed Rehabilitation Area were dominated by koala habitat tree species
including M. quinquenervia, L. suaveolens and E. robusta. The rehabilitation strategy prescribed
within this Rehabilitation Plan will result in a large increase of koala habitat within the locality.
Furthermore, the extension of the habitat to a width of 10m either side of the waterway is
expected to enhance and improve the existing habitat value and contribute to maintaining and
improving the water quality of the waterway and downstream receiving environments.

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PLATE 1 - RIPARIAN REHABILITATION AREA

   

3

 

 

RIPARIAN REHABILITATION PLAN
21 JIRRIMA CRESCENT,
COOROIBAH

 

 

LEGEND
DEVELOPMENT SITE

[_] access easEMENT

[EBB Riparian REHABILITATION AREA
APPROXIMATELY 0.2ha

 

 

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