Onkaparinga Estuary Management Plan€¦ · Prepared as a joint initiative for Land SA, Adelaide Mt...

Onkaparinga Estuary Management Plan

Copy for distibution

August 2008

Onkaparinga Estuary Management Plan

August 2008

Prepared as a joint initiative for Land SA, Adelaide Mt Lofty Ranges Natural Resources Management Board, City of Onkaparinga,

Department for Environment and Hertiage, Friends of Onkaparinga Parks.

Prepared by Environmental & Biodiversity Services

Onkaparinga Estuary Management Plan 2008

Environmental and Biodiversity Services 3

Table of Contents Acknowledgements .................................................................................................... 6

1. Introduction .......................................................................................................... 7

1.1 Location .......................................................................................................... 7

1.2 Recent works undertaken ............................................................................... 8

1.3 Management Objectives ...................................................................................... 9

2. Management Areas ............................................................................................ 10

3. Vegetation .......................................................................................................... 13

3.1 Pre-European Vegetation Associations ........................................................ 13

3.2 Remnant Vegetation ..................................................................................... 15

3.3 Existing Vegetation and Condition ................................................................ 19

3.4 Weeds .......................................................................................................... 21

4. Management issues ........................................................................................... 22

4.1 Weed Control and Prioritisation .................................................................... 22

4.1.1 Management of Weeds ......................................................................... 22

4.1.2 Management of Non-local Native Plantings ........................................... 23

4.1.3 Time and Cost Estimate for Weed Control, Slashing and Bushcare...... 23

4.2 Fauna management...................................................................................... 24

4.2.1 Rabbits and Hares ................................................................................. 24

4.2.2 Kangaroos ............................................................................................. 25

4.3 Monitoring ..................................................................................................... 25

4.4 Slashing and Encouragement of Native Grass Regeneration ....................... 26

4.5 Revegetation ................................................................................................ 27

4.5.1 Site preparation and planting ................................................................. 28

4.5.2 Revegetation Species List ..................................................................... 30

4.6 Management Activities calendar ................................................................... 31

5. Description of Management Areas. ..................................................................... 32

5.1 Management Area 1. .................................................................................... 34

5.2 Management Area 2. .................................................................................... 42

5.3 Management Area 3. .................................................................................... 46

5.4 Management Area 4. .................................................................................... 51

5.5 Management Area 5. .................................................................................... 60

5.6 Management Area 6. .................................................................................... 65

5.7 Management Area 7. .................................................................................... 72

5.8 Management Area 8. .................................................................................... 79

5.9 Management Area 9. .................................................................................... 83

5.10 Management Area 10. .................................................................................. 85

5.11 Management Area 11. .................................................................................. 88

6. References ............................................................................................................. 92

Tables TABLE 1 - MANAGEMENT AREAS AND PRIORITIES ............................................................. 11 TABLE 2 - REMNANT SPECIES OBSERVED WITHIN THE ONKAPARINGA ESTUARY DURING THE

CURRENT SURVEY. ................................................................................................. 16 TABLE 3 - CONDITION RATINGS OF UNDERSTOREY .......................................................... 19 TABLE 4 - DECLARED WEED SPECIES UNDER THE NATURAL RESOURCES MANAGEMENT ACT

2004 RECORDED WITHIN THE ONKAPARINGA ESTUARY RECREATION PARK. ................ 21 TABLE 5 - MANAGEMENT ACTIVITIES CALENDAR .............................................................. 31 TABLE 6 - REVEGETATION DESCRIPTION FOR MANAGEMENT AREA 1 (FIG 2) ...................... 36 TABLE 7 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 1. ........................... 38 TABLE 8 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 2. ........................... 43 TABLE 9 - REVEGETATION DESCRIPTION FOR MANAGEMENT AREA 1 (FIG 5) ...................... 47 TABLE 10 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 3. ......................... 49 TABLE 11 - REVEGETATION DESCRIPTION FOR MANAGEMENT AREA 4, SITE 1. ................... 52 TABLE 12 - SITE 1 REVEGETATION SPECIES LIST .............................................................. 53 TABLE 13 - SITE 1 DIRECT SEEDING MIX .......................................................................... 53 TABLE 14 - REVEGETATION DESCRIPTION FOR MANAGEMENT AREA 4, SITE 2. ................... 54 TABLE 15 - SITE 2 REVEGETATION SPECIES LIST. ............................................................. 54 TABLE 16 - SITE 2 DIRECT SEEDING MIX. ......................................................................... 55 TABLE 17 - PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 4. .......................... 56 TABLE 18 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 5. ......................... 62 TABLE 19 - REVEGETATION DESCRIPTION FOR MANAGEMENT AREA 6. .............................. 67 TABLE 20 - PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 6. .......................... 69 TABLE 21 – REVEGETATION DESCRIPTION FOR MANAGEMENT AREA 7 .............................. 74 TABLE 22 - PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 7. .......................... 76 TABLE 23 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 8. ......................... 81 TABLE 24 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 10. ....................... 86 TABLE 25 – PRIORITY WEEDS OCCURRING WITHIN MANAGEMENT AREA 11. ....................... 90

Figures FIGURE 1 – LOCATION OF MANAGEMENT AREAS WITHIN THE ONKAPARINGA ESTUARY. ....... 32 FIGURE 2 – MANAGEMENT AREA 1 PEST PLANT DISTRIBUTIONS ....................................... 40 FIGURE 3 – MANAGEMENT AREA 1 PROPOSED REVEGETATION SITES ................................ 41 FIGURE 4 – MANAGEMENT AREA 2 PEST PLANT DISTRIBUTIONS. ...................................... 45 FIGURE 5 - MANAGEMENT AREA 3. PEST PLANT DISTRIBUTION, RATED SPECIES AND

PROPOSED REVEGETATION SITES. .......................................................................... 50 FIGURE 6 – MANAGEMENT AREA 4 PEST PLANT DISTRIBUTIONS, RATED SPECIES

DISTRIBUTION. ....................................................................................................... 58 FIGURE 7 – MANAGEMENT AREA 4 PROPOSED REVEGETATION SITES, PROPOSED BUSHCARE

SITE. ..................................................................................................................... 59 FIGURE 8 – MANAGEMENT AREA 5, PEST PLANT DISTRIBUTIONS. ..................................... 64 FIGURE 9 – MANAGEMENT AREA 6, PEST PLANT DISTRIBUTION, RATED SPECIES, PROPOSED

REVEGETATION SITE. ............................................................................................. 71 FIGURE 10 – MANAGEMENT AREA 7, PEST PLANT DISTRIBUTIONS, PROPOSED REVEGETATION

SITES. ................................................................................................................... 78 FIGURE 11 – MANAGEMENT AREA 8 PEST PLANT DISTRIBUTION AND PROPOSED

REVEGETATION SITE. .............................................................................................. 82 FIGURE 12 - MANAGEMENT AREA 9. ............................................................................... 84 FIGURE 13 – MANAGEMENT AREA 10, PEST PLANT DISTRIBUTIONS, PROPOSED BUSHCARE

SITE. ..................................................................................................................... 87 FIGURE 14 – MANAGEMENT AREA 11, PEST PLANT DISTRIBUTIONS. ................................. 91



Acknowledgements

The Onkaparinga Estuary Management Action Plan was initiated by Land SA in partnership with National Parks and Wildlife. A steering committee which guided the development of this report included: Bryn Troath (Department for Environment and Heritage, Regional Conservation) Dr Wendy Stubbs (Department for Environment and Heritage, Regional Ecologist) Ben Moulton (Urban Forest Program) Carolyn Woods (Department for Environment and Heritage, Urban Forests) Chris Gibson (Department for Environment and Heritage, Urban Forests) Hafiz Stewart (Department for Environment and Heritage) James Crocker (Department for Environment and Heritage) Leah Egan (Department for Environment and Heritage) Phil Elson (Natural Resource Management Board) Travis How (Environmental and Biodiversity Services) Chris Harrison (Environmental and Biodiversity Services)



1. Introduction

As a result of the development of a large parcel of land at Seaford Meadows, Land SA (the proponent) have agreed to fund $200,000 of revegetation and weed control works in the area. However, due to a lack of sites within the boundaries of the proposed development, alternative options on nearby lands have been assessed. National Parks and Wildlife were approached in relation to the feasibility of undertaking works within the Onkaparinga River Recreation Park. It was suggested that the funding could complement any existing programs for the area which currently is being implemented. A meeting was held with Bryn Troath (National Parks and Wildlife), Dr Wendy Stubbs (Regional Ecologist, DEH) and Ben Moulton (Urban Forest Program). The meeting was held to discuss possible options and what activities could be undertaken. Due to constraints of requiring the funding to be spent in close proximity to the development site, Areas 4 and 6 (see section 5) were nominated as the project area. Numerous activities were discussed and the works to be undertaken will be based broadly on the priorities outlined for Areas 4 and 6 in section 5. This includes the removal of woody weeds, the removal of an area of Pyramid Trees and revegetation. In addition to this, the removal of planted non-local native tree species. It was agreed that the funding would be spread over the whole of the recreation park as substantial previous works had been completed within Areas 4 and 6 and the funding would support the practice of landscape biodiversity management which in essence supports the long term rehabilitation of Areas 4 and 6 and the estuary as a whole. As Area 4 and 6 is located within the Onkaparinga River Recreation Park, it was further suggested that an assessment of the whole Onkaparinga estuary system be implemented identifying key management issues at a terrestrial level and from this the following management plan came into place. Please note that the Supporting Document for the Onkaparinga Estuary Management Plan should be referred to where appendices are cited within the following management plan. 1.1 Location

The Onkaparinga Estuary is located within the City of Onkaparinga and is approximately 35 kilometres south of Adelaide. The Estuary section of the Onkaparinga River is approximately 10.5 kilometres in length and covers an area of approximately 425 hectares, beginning at the eastern side of Old Noarlunga, it flows downstream in a westerly direction winding its way were it meets the ocean at Port Noarlunga South. The majority of the estuary occurs within the Onkaparinga River Recreation Park with the estuary mouth occurring within the Port Noarlunga Aquatic Reserve.



1.2 Recent works undertaken

The Onkaparinga Estuary is an important area for both conservation and recreational use. Many efforts to improve the health of the area have been undertaken in the past with various levels of success. Constructed wetlands have been put in place to capture storm water before entering the Onkaparinga River and have included revegetation efforts to create a wetland habitat. The constructed wetlands provide a safe refuge for waterbirds including migratory species. Heavy metals and other chemicals found in storm water are filtered through these constructed wetlands before entering the estuary system. Other revegetation efforts have been undertaken due to the lack of diversity of native vegetation within the reserve. Planting of tubestocks and direct seeding have been undertaken to establish native species within the park. More recent works within the Recreation Park have included the control and removal of invasive plant species such as African Boxthorn throughout the whole Recreation Park and Casuarina glauca (Swamp Oak) within Management Area 5 (see section 5). The Friends of the Onkaparinga Estuary group are actively undertaking weed control in various areas using bush care techniques. The group have an extensive knowledge of flora and flora of the area having undertaken various biological surveys of the area. An important recommendation which has been included within each Management Area (were relevant) is to continue implementing these recent works to ensure the required outcomes are achieved and the time and effort already put into the actions is not wasted.



1.3 Management Objectives

The following management objectives are recommended in order to enhance the existing vegetation and promote greater biodiversity and habitat values, while also reducing fire risk within the reserve.

Objective 1 – Conservation and restoration of existing remnants

Objective 2 – Promotion of native grasses and other grassland species

Objective 3 – Control all high priority weed species

Objective 4 – Implement revegetation program

Objective 5 – Control other lower priority weed species

Objective 6 – Control hares and rabbits

Objective 7 – Re-evaluate management plan effectiveness



2. Management Areas

This management plan retains the Management Areas that were identified within the Onkaparinga Estuary Rehabilitation Action Plan (2006) to keep consistency between the two reports. The distribution of these Management Areas are shown in Figure 3. The Onkaparinga Estuary was divided into these Management Areas to allow a program to be developed which focused on priority actions and other management issues within the different areas. The management areas were determined by the dominant vegetation association present, quality of the native vegetation present, the weed species present, the landform of the area and through consultation with stakeholders. Within the body of this report each Management Area has information on the following;

Area

Priority Rating

Area Description and Condition

Significant Flora

High Priority Weeds

Pest Animal Species

Area Action Plan

Native Grass Patches

Revegetation Description

Revegetation Cost Estimate (ex GST)

Weed Control Objectives

Weed Control Cost Estimate (ex GST)

Bush Care

Monitoring The Management Areas have been prioritised by assessing the “intactness” of the remnant vegetation and biodiversity values of the site. This will enable land managers to determine which areas should have on-ground works undertaken as a priority. The management unit labels do not reflect the prioritisation order of the management units.

Table 1 - Management Areas and Priorities

Priority

Order

Management Area Area (Ha)

Priority Actions

Pre-European Vegetation association

1 10 11 1. Weed Management;

2. Monitoring.

Chenopod Low Shrubland

2 11 13.5 1. Weed Management;

2. Monitoring.



2. Monitoring.



2. Monitoring.

Eucalyptus porosa (Mallee Box) Woodland, Chenopod Low Shrubland


2. Revegetation;

3. Monitoring.

Eucalyptus camaldulensis (river red gum) over Juncus spp. (rush) Open woodland


2. Monitoring.



2. Revegetation;

3. Monitoring.



2. Revegetation;

3. Monitoring.



2. Revegetation;

3. Monitoring.



2. Revegetation;




Priority

Order

Management Area Area (Ha)

Priority Actions

Pre-European Vegetation association

3. Monitoring.

11 9 30 None Eucalyptus porosa (Mallee Box) Woodland, Chenopod Low Shrubland



3. Vegetation

3.1 Pre-European Vegetation Associations

Three broad vegetation associations were believed to occur within the Onkaparinga

Estuary before European settlement (http://www.urbanforest.on.net 2005). These were:

Eucalyptus camaldulensis (River red gum) over Juncus spp. (Rush) Open woodland.

Nitraria billardierei (Nitre-bush), +/- Maireana oppositifolia (Salt bluebush), +/- Sarcocornia spp. (Samphire), +/- Halosarcia spp. (Samphire), +/- Atriplex paludosa (Marsh saltbush) Low shrubland.

Olearia axillaris (Coast daisy-bush), Acacia longifolia var. sophorae (Coastal wattle) Tall shrubland.

An additional three broad vegetation associations occurred surrounding the Onkaparinga Estuary. These were:

Eucalyptus porosa (Mallee box), Melaleuca lanceolata (Dryland tea-tree), Allocasuarina verticillata (Drooping sheoak) Open woodland.

Allocasuarina verticillata (Drooping sheoak), +/- Acacia cupularis (Cup wattle), +/- Beyeria lechenaultii (Pale turpentine bush), +/- Nitraria billardierei (Nitre-bush) Low shrubland.

Beyeria lechenaultii (Pale turpentine bush), +/- Calytrix tetragona (Common fringe-myrtle), +/- Acacia cupularis (Cup wattle), +/- Alyxia buxifolia (Sea box), +/- Santalum acuminatum (Quandong) with emergent Eucalyptus porosa (Mallee box) Low shrubland.

Species identified as being native to each of these vegetation associations are presented in Appendix 10. These lists were obtained from: http://www.urbanforest.on.net (2005). It should be noted that these species lists are generic and are not site specific, and the original native vegetation that occurred on site before European settlement may not have contained all of these species and it is possible that additional species would have also occurred in these areas. The Eucalyptus camaldulensis (River red gum) over Juncus spp. (Rush) Open woodland began upstream east of the town of Old Nourlunga and extended downstream to just past the existing South Road Bridge where the Nitraria billardierei (Nitre-bush), +/- Maireana oppositifolia (Salt bluebush), +/- Sarcocornia spp. (Samphire), +/- Halosarcia spp. (Samphire), +/- Atriplex paludosa (Marsh saltbush) Low shrubland became more dominant. These vegetation associations within the Onkaparinga Estuary were surrounded by Eucalyptus porosa (Mallee box), Melaleuca



lanceolata (Dryland tea-tree), Allocasuarina verticillata (Drooping sheoak) Open woodland. The estuary vegetation continued down stream to near the mouth of the estuary where Olearia axillaris (Coast daisy-bush), Acacia longifolia var. sophorae (Coastal wattle) Tall shrubland became more dominate within the coastal dune system. Surrounding this association was a Beyeria lechenaultii (Pale turpentine bush), +/- Calytrix tetragona (Common fringe-myrtle), +/- Acacia cupularis (Cup wattle), +/- Alyxia buxifolia (Sea box), +/- Santalum acuminatum (Quandong) with emergent Eucalyptus porosa (Mallee box) Low shrubland north of the estuary mouth and Allocasuarina verticillata (Drooping sheoak), +/- Acacia cupularis (Cup wattle), +/- Beyeria lechenaultii (Pale turpentine bush), +/- Nitraria billardierei (Nitre-bush) Low shrubland south of the estuary mouth.



3.2 Remnant Vegetation

A total of 53 indigenous flora species were recorded within the Onkaparinga Estuary during the current survey (see Appendix 4). Several of these species are considered to be remnant within the area whilst other indigenous species have been planted on site. The number of species recorded is considered to be an underestimation of the indigenous flora present within the area. Some portions of the survey area had been recently slashed hence some indigenous species may not have been observed. Furthermore, some annual plant species may have already died down for the season and hence not been observed during the survey. The majority of species that are considered to be remnant occur within the intertidal, supratidal and River Bank areas were flora species are exposed to various tidal and seasonally inundation by water. These species are considered to be relics of the original vegetation within the reserve and also have great conservation values due to the poor quality of native vegetation within the reserve. Remnant species observed during the current survey are presented in the following table, along with their conservation status and the Management Area within which they were observed. The location of each Management Area is presented within Figure 3 and each Management Area is discussed in Section 5.



Table 2 - Remnant species observed within the Onkaparinga Estuary during the current survey.

SPECIES COMMON NAME

CONSERVATION RATING Management Area

AUS SA SL 1 2 3 4 5 6 7 8 10 11

Atriplex semibaccata Berry Saltbush * * * * * * *

Atriplex suberecta Lagoon Saltbush * * * * * * *

Austrodanthonia caespitosa Common Wallaby-grass * * *

Austrostipa nodosa Tall Spear-grass * * *

Avicennia marina ssp. australasica Mangrove *

Boerhavia dominii Tar-vine * * * * * *

Chenopodium pumilio Clammy Goosefoot * * * * * *

Convolvulus remotus Grassy Bindweed * *

Cyperus gymnocaulos Spiny Flat-sedge *

Cyperus vaginatus Stiff Flat-sedge *

Dianella revoluta var. revolute Black-anther Flax-lily * *

Disphyma crassifolium ssp. clavellatum Round-leaf Pigface * * * * * * *

Einadia nutans ssp. nutans Climbing Saltbush * * * * * * *

Enchylaena tomentosa var. tomentosa Ruby Saltbush * * * * * * * *

Enneapogon nigricans Black-head Grass * *

Eucalyptus camaldulensis var. camaldulensis River Red Gum * * *

Frankenia pauciflora var. fruticulosa Southern Sea-heath * * * * * * *

Frankenia pauciflora var. gunnii Southern Sea-heath * * * * * * *

Gahnia filum Thatching Grass R * * *

Gonocarpus mezianus Broad-leaf Raspwort * * * * * * *

Halosarcia halocnemoides ssp. Halocnemoides Grey Samphire * * * * *

Halosarcia pergranulata ssp. pergranulata Black-seed Samphire * * * * *

Isolepis nodosa Knobby Club-rush *



SPECIES COMMON NAME

CONSERVATION RATING Management Area

AUS SA SL 1 2 3 4 5 6 7 8 10 11

Juncus usitatus Common Rush *

Myoporum insulare Common Boobialla * * *

Nitraria billardierei Nitre-bush * * * * * *

Phragmites australis Common Reed *

Pittosporum angustifolium Native Apricot R *

Rhagodia candolleana ssp. candolleana Sea-berry Saltbush * * * * * * *

Salsola kali Buckbush * * *

Sarcocornia blackiana Thick-head Samphire * * * * * * *

Sarcocornia quinqueflora Beaded Samphire * * * * * * *

Sclerostegia arbuscula Shrubby Samphire * * * * * * *

Suaeda australis Austral Seablite * * * * * * *

Themeda triandra Kangaroo Grass * * * * * * *

Threlkeldia diffusa Coast Bonefruit * * * * * * *

Typha domingensis Narrow-leaf Bulrush * * * * * *

Vittadinia blackii Narrow-leaf New Holland Daisy R * *

SL = Southern Lofty, SA = South Australia, AUS = Australia

Conservation Ratings X = Presumed extinct; not recorded for more than 50 years E = Endangered ; rare and in danger of becoming extinct V = Vulnerable ; rare and at risk from potential threats in the long term T = Threatened ; rare and likely to become either endangered or vulnerable R = Rare having a low overall frequency, confined to a restricted ranged or scattered sparsely over a wider area K = Uncertain ; either threatened or rare but insufficient data for a more precise assessment. U = Uncommon ; less common species but not rare



N = Not considered to be in danger Q = Not yet assessed but flagged as being of possible significance



3.3 Existing Vegetation and Condition

Vegetation within the Onkaparinga Estuary has been highly modified due to stock grazing and clearance for agriculture in the past which has resulted in the present mosaic of vegetation communities within the reserve. Condition Ratings were assigned during the field survey and record the extent to which exotic vegetation has replaced the native understorey species. This is a subjective assessment that is based upon and rated relative to the probable “pre-European” settlement state of the vegetation. Condition ratings are therefore predominantly a description of the understorey condition and extent, and are described in the following table:

Table 3 - Condition Ratings of Understorey

Condition Rating Condition Description of Understorey

Excellent Excellent quality native vegetation, containing very few or no exotic species

Good Good quality native vegetation, containing few exotic species

Moderate Moderate quality native vegetation, containing an even mix of native and exotic species

Poor Poor quality, containing little native vegetation, exotic species being more common then natives

Very Poor Very poor quality, very little or no native vegetation, exotic species dominating

Remnant vegetation communities occur mainly in areas that are exposed to various tidal and seasonally inundation by water. Three remnant communities were identified and include:

Intertidal Samphire Communities

Supratidal Samphire Communities

Gahnia filum (Chaffy Saw-sedge) Open Sedgeland Intertidal Samphire Communities occurs in Management Areas 4, 8, 9, 10 and 11. Vegetation within this association is exposed to regular tidal fluctuations and water levels, and is considered to be in good condition being relatively intact. The vegetation is dominated by a mix of indigenous species such as Halosarcia halocnemoides ssp. Halocnemoides (Grey Samphire), Sarcocornia quinqueflora (Beaded Samphire) and Nitraria billardierei (Nitre-bush). Exotic species such as Limonium companyonis (Sea-lavender), Piptatherum miliaceum (Rice Millet) and Lycium ferocissimum (African Boxthorn) occur scattered throughout the association. The areas where the Intertidal



Samphire Communities occur are considered to be important conservation areas due to providing significant habitat for migratory bird species. Supratidal Samphire Communities occurs in Management Areas 8, 9, 10, 11. Vegetation within this association is exposed to season water level fluctuations and is considered to be relatively intact and in good condition. Dominant indigenous species include Atriplex suberecta (Lagoon Saltbush), Atriplex semibaccata (Berry Saltbush) and Nitraria billardierei (Nitre-bush). Exotic species such as Limonium companyonis (Sea-lavender), Piptatherum miliaceum (Rice Millet) and Lycium ferocissimum (African Boxthorn) occur scattered throughout the association. The areas where the Intertidal Samphire Communities occur are also considered to be important conservation areas due providing significant habitat for migratory bird species. Gahnia filum (Chaffy Saw-sedge) Open Sedgeland occurs in Management Areas 8, 10 and 11. Vegetation within this association is considered to be in good condition with indigenous species such as Gahnia filum (Chaffy Saw-sedge) which is rare within the Southern Lofty Botanical region, Threlkeldia diffusa (Coast Bonefruit) and Nitraria billardierei (Nitre-bush) dominating the association. Exotic flora species such as Avena barbata (Bearded Oat) and Galenia pubescens var. pubescens (Galenia) occur scattered throughout the association. These remnant communities make up only a small proportion of the vegetation within the reserve. The remaining areas are considered to be in poor to very poor condition dominated by exotic species, planted vegetation, large stands of various Eucalyptus spp., constructed wetlands, revegetation sites and exotic grasslands. Very little native vegetation occurs throughout the remaining areas with very low recruitment. Many problematic weeds also occur scattered throught the reserve at various densities. See section 5 for a more detailed description of the condition of vegetation for each Management area.



3.4 Weeds

Weeds are considered to be the most significant threat to the Onkaparinga Estuary. Numerous problems are being caused by weed invasion including biodiversity loss, habitat modification and loss, loss of amenity value, loss of recreational value and increase in fire risk. Immediate and long term action on weed control is required to reduce the impact of weeds on the above values. Weed control methods, timing and other information are listed in Appendix 1. A total of 50 weed species were recorded during the current survey (see Appendix 2). Additional problematic weeds may be present within the reserve but were not observed during the survey period due to the time of year the survey was undertaken. Some species, such as Asparagus asparagoides (Bridal Creeper), Watsonia meriana cv. Bulbillifera (Bubil Watsonia), Oxalis pes-caprae (Soursob), Diplotaxis tenuifolia (Lincoln Weed) and some annual grass species may not have been observed in some areas due to them dying off prior to the survey. The following table lists those weed species observed within the project site that are declared under the Natural Resources Management Act 2004. Table 4 - Declared Weed Species under the Natural Resources Management Act 2004 recorded within the Onkaparinga Estuary Recreation Park.

SPECIES COMMON NAME

Asphodelus fistulosus Onion Weed

Cynara cardunculus ssp. flavescens Artichoke Thistle

Echium plantagineum Salvation Jane

Euphorbia terracina False Caper

Lycium ferocissimum African Boxthorn

Marrubium vulgare Horehound

Olea europaea ssp. cuspidate African Olive

Opuntia sp. Prickly Pear

Pinus halepensis Aleppo Pine

Pennisetum macrourum African Feather-grass

Solanum elaeagnifolium Silver-leaved nightshade

Tamarix aphylla Athel Pine



4. Management issues 4.1 Weed Control and Prioritisation

4.1.1 Management of Weeds

Weed control is seen as the highest priority issue within this reserve. All weed species recorded within a Management Area have been given a priority rating of 1, 2, 3 and 4. The ratings have been given to determine which weeds should be managed first within each Area, in the event that all species can not be controlled at the same time. The ratings are described as follows: Priority Rating 1 – These weeds are considered to be high impact exotic flora species with a large ability to impact on native vegetation. They either have the ability to spread quickly or the potential to overrun, smother or out compete with native vegetation. This also includes outbreaks of declared or environmental weed species not previously recorded within the reserve. These should be eradicated before they have the opportunity to become established and spread throughout the reserve. Priority Rating 2 – These weeds are considered to be slower spreaders than priority 1 species, or have less of an impact in displacing the original native vegetation. Priority Rating 3 – These weeds are considered to have a much lower impact on the native vegetation, and include species that spread at a much slower rate or not at all. They also are less likely to have as much of an impact on displacing the original native vegetation.

Priority Rating 4 – These weeds are species that have the characteristics of priority 1 or 2 species, but due to their entrenched nature, control is considered to be unrealistic unless large amounts of time, effort and consistent long term management practices are implemented. The plan for this reserve has concentrated on the controlling of significant environmental and declared weeds, particularly weeds that are highly invasive or have a large impact on biodiversity values and fire risk. Weeds such as Wild Oats or Soursob which are relatively common in different parts of the reserve and also have a significant impact, have currently been ignored as it is considered to be too costly and time consuming to control these weeds at this stage. It is hoped that at a later stage when other priority 1, 2 and 3 species have been controlled that attention may be shifted towards controlling some of these species. If any new outbreaks of the priority weed species occur, they should also be controlled before the lower priority weeds. It may need to be accepted that some species, for example Wild Oats, are now naturalized species that will only ever be controlled in bushcare sites, and that over the majority of the reserve effective control is not achievable. Slashing has been allowed for in all zones in an attempt to control species such as Wild Oats while promoting native grasses, but this is the limit of control efforts on this species.



4.1.2 Management of Non-local Native Plantings

Many plantings of non-local native trees and shrubs, and exotic trees have occurred on the site over the last thirty years. Exotic trees have been recommended for removal as part of the weed control program, generally within the first three years. However, the Non-local native trees and shrubs will be retained at this stage and where possible revegetation clumps will be planted near them. As revegetation plantings grow and provide alternative habitat and food sources to local fauna, the control of the existing planted Non-local native trees can occur if considered necessary. If these trees and shrubs are controlled, where possible trees should be left standing as habitat, or if considered dangerous can be felled to provide habitat on the ground. Were possible it is recommended that slashing of exotic understory be undertaken. In areas where both native and weedy grasses are to be slashed, slashing should be done using the native grass encouragement in section 4.4. Slashed material should be bailed or piled up and burnt. This will help to reduce high levels of nutrients entering the soil and allow conditions to become more favorable for native flora.

4.1.3 Time and Cost Estimate for Weed Control, Slashing and Bushcare.

Each management Area has an estimate for weed control included for a five year period. This estimate was prepared in the field and is based on time estimates prepared during the field survey, and an hourly rate of $55 per labourer (plus GST). Each time and cost estimate table has the number of labourer hours given, with the cost in dollars given in brackets after this. The cost for a chipper to remove larger branches and trunks of woody weeds has also been included. Chipper cost was based on an hourly rate of $110 per hour, for a chipper truck and driver. Weed control staff would be needed to assist the chipper operator in organising material to be chipped and in feeding the chipper. Material to be chipped will be stockpiled so that the hire of costly machinery is kept to a minimum. Where appropriate the cost of slashing with a tractor towed slasher has been included. An hourly rate of $60 per hour includes the cost of the labourer and the machinery. A bushcare approach is based on minimal impact weed control such as hand weeding or careful use of herbicides, and is suited to areas where there are a large number of natives in the understorey along with the weeds. It is a long term strategy requiring dedicated volunteers or contractors who are trained in bushcare techniques, plant recognition and safe herbicide use. The Bush For Life program may provide the opportunity to engage trained volunteers to actively work on good quality remnant sites. If suitable areas were observed during the field survey, they have been recommended in the section on each management zone. A bushcare approach is to be based on the following principles:

Should be carried out by trained volunteers or trained bush regeneration contractors.

Weed from the least degraded areas to the most degraded areas.

Selective methods appropriate to the weed (see Appendix 1) should be used.



Spend time in one target area to remove all of the priority weeds so that one weed species is not replaced by another.

A small area weeded thoroughly has a greater chance of natural regeneration in the long term than a large area done carelessly.

Do not weed too large an area, as follow up weeding must cover this area. Only start an area that you know will not be too large to do the follow up weeding in.

After a season of plant growth, follow up work must be undertaken. Hand pull seedlings and treat regrowth before weeds develop extensive roots or produce seed. This step is critical to reinforce progress and to prevent re-invasion of weed species within the controlled area. The importance of follow up work can not be over-emphasised.

Maintain the weeded area in the following years, keeping it permanently weed free by regularly removing weeds before they take hold.

When not many weeds are coming up in a weeded area and less time is needed to maintain it, select a new target area that is slightly weedier and start the process again, or expand your work outwards from the original area.

In situations where little or no regeneration of native plants is occurring, a revegetation program, using plants grown from locally collected seed should be considered.

Where appropriate the cost of bushcare contractors has been included. An hourly rate of $55 per hour should enable qualified and experienced bushcarers to be contracted.

4.2 Fauna management

4.2.1 Rabbits and Hares

Several rabbits and hares were observed during the field survey. It is recommended that all rabbits be controlled in this reserve, due to the severe damage they can cause by grazing native plants and disturbing soils at their warren site. There is currently no control of rabbits or hares on this site. Options for their management in a suburban area are restricted to ripping of warrens (for rabbits), fumigation of warrens (for rabbits), poisoning or shooting. Shooting is considered to be undesirable due to the close proximity of houses and the frequent human activity within the park. Poisoning (with Pindone) needs to be undertaken carefully in a suburban area due to the risk of poisoning other animals or humans. Local residents need to be made aware of any poisoning being undertaken via personal correspondence and/or adequate signage. Fumigation, or the gassing of a closed in warren, should be carried out by a licensed and trained pest control operator. It is essential to work with neighboring properties, to ensure coordinated and targeted feral animal control is undertaken, maximising control success. The most viable control options for this site is therefore ripping of warrens. If baiting or poisoning is desired then the Natural Resource Management Board should be consulted for appropriate methods.



4.2.2 Kangaroos

The impact of Kangaroos on native vegetation within the Onkaparinga Estuary reserve is unknown. An in-depth survey on population numbers and their impact on native vegetation is required to determine if management is necessary.

A detailed survey of fauna issues within the reserve is currently being undertaken by the Friends of the Onkaparing Estuary. A summary of the findings will become an appendix within the Supporting Document for the Onkaparinga Estuary Management Plan at a later date.

4.3 Monitoring

Implementing a monitoring program is important to ensure that efforts are being rewarded with an improvement in vegetation condition. It is recommended that monitoring of implemented actions be undertaken within this reserve. This should include installing photopoints, installing monitoring sites or through visual inspections of weed infestations and of good quality vegetation. The level and methodology for the monitoring needs to be developed. The responsibility for co-ordinating and undertaking monitoring activities needs to be determined. As a minimum monitoring should include weed infestations and revegetation areas. Weed infestations should be inspected regularly to determine whether they are spreading or increasing in density. The areas of good quality native vegetation should also be regularly inspected to ensure early detection of new weed species or other issues. This will reduce the long-term cost of management of the weed species as they can usually be controlled very easily when they are small in size. Monitoring sites should be set up in bushcare and revegetation areas using a methodology developed and designed in conjunction with the DEH Regional Ecologist. The monitoring design selected should ensure that quantifiable and objective data is recorded that can be recollected over time to more accurately determine the success of the implemented management actions. If positive changes are resulting from the work being carried out, then native plant species and abundance is expected to increase over time, with a corresponding decrease in weed species diversity and abundance. It is also anticipated that if the revegetation aspects of the plan are successful, the revegetation areas will see a decrease in weed species cover and an increase in native species cover and growth. The Urban Forests One Million Trees program photopoint methodology could possibly be used as a simple methodology, and it is presented in Appendix 5. More information on different photopoint methodologies can be obtained from various sources including the Department for Environment and Heritage or Trees For Life.



4.4 Slashing and Encouragement of Native Grass Regeneration

Significant stands of native grasses still occur in this reserve in association with other weeds. In areas where access is possible, these areas are currently being slashed in an ongoing maintenance and fire control program. The mowing regime in these areas should be changed so that the native grasses are encouraged and the annual grasses and weeds are slashed. This can be done by careful mowing around the native grasses, or by slashing with a hand held brush cutter, so that the native grasses are not slashed, but the weeds are. If slashing by hand is too time consuming or labour intensive, mower slashing during September or October will still be advantageous as most of the native grasses, being later seeders will still have time following slashing, to flower and set seed. Native perennial grasses should be encouraged because many of them are summer active and hence are green (with higher moisture content) during the fire danger season, and consequently pose less of a fire hazard. Native grasses also do not have the biomass of some of the introduced grasses and therefore provide less fuel for a fire. In areas where both native and weedy grasses are to be slashed, slashing should be done after the annual grasses have flowered and before their seeds have matured. As a general rule slashing of annual grasses should occur between September and November, but will vary depending on the season. Most of the native perennial grasses flower later hence their seed set is almost certain to still occur. Slasher operators will need to interpret the readiness of annual grasses for slashing through field inspections to ensure that it occurs at the correct time. As many annual grasses will re-shoot, slashing will need to occur twice, so that any regrowth after the initial slashing is removed. This should be enough in most seasons to stop annual grasses from setting seed. The carrying out of hygiene procedures are critical in the implementation of any slashing program, to ensure that weed species are not spread further around the site or new species are introduced to the site. Please see Appendix 6 for appropriate hygiene procedures to prevent the spread of weeds.



4.5 Revegetation

The aim of revegetation within the Onkaparinga estuary is to increase biodiversity of plant species while trying to broadly represent the pre-european vegetation associations present within the area and to enhance the remaining remnant vegetation. The following general principles have been applied:

Use species that grow locally in the area, and in the pre-European vegetation association that is trying to be replicated.

Try to mimic the natural patchiness of the vegetation, with a random placement of clumps and open spaces.

Revegetation will generally occur in 30m x 30m (900m2) clumps. Clumps will consist of a mix of trees, shrubs and groundcovers/ low shrubs, planted as tubestock in the 20m x 20m (400m2) central core of the clump.

A total revegetation coverage of 20% of the land area is the target of this revegetation program. Therefore two clumps (covering 1800m2) have been allowed for in every hectare (10,000m2). This coverage aims to mimic an open woodland association, and is also designed to allow for easy access for maintenance vehicles such as slashers.

Clumps are where possible to be placed around existing planted native trees, and can be joined together where appropriate to make larger clumps.

Clumps should be placed in areas that are dominated by weeds and where no native understorey occurs.

Do not plant in patches of native grasses and other native understorey species and sites where natural regeneration is likely to occur. Areas with a good native cover should be encouraged to regenerate, and allowed to disperse their seed into areas where weeds have been controlled.

All plants should be grown from seed collected on site, or from seed collected from remnant vegetation that is as close as possible to the site.

An excess of plants has been built in to the numbers of species being planted to cope with an anticipated 25% loss of plants.

Consideration of fire management needs to be taken into account when designing revegetation layouts. In particular planting should not occur within slashing Areas or within 5m of boundary fences (see Appendix 7 for further revegetation design principles).

Management Area 4 has been identified as an area where direct seeding will be utilised using a mix of Chenopod species. The rationale for direct seeding in Management Area 4 is to:

provide a living mulch to the site,

compete with weeds due to their ground covering habit,

reduce maintenance costs through out-competing weeds, and

contribute to the habitat value through the addition of another strata and greater species diversity.



4.5.1 Site preparation and planting

Areas where revegetation is to occur will need to be properly prepared by controlling weeds. Weed control should occur two to three weeks before planting is scheduled to begin. Appropriate use of herbicides in regard to weather conditions, handling of chemicals, safety of users and the public, and safety of the environment and non-target species is essential. Any contractors or council staff used for this work must be fully licensed and use qualified experienced staff to ensure best practice herbicide use techniques are followed. All of the revegetation recommended for this reserve, will be set out in clumps. The methodology is detailed below.

Clumps

Clumps should be placed in areas that are dominated by weeds and where no native understorey occurs. Where possible clumps will be located in and around existing trees.

Mark the area with several marker stakes (painted with a bright colour) to delineate the edge of the clump.

Ensure weather conditions are appropriate for spraying.

Blanket spray the area (avoiding any native species, of which there should be few or none if the area has been chosen correctly).

The first weed spray should be undertaken in the spring prior to the planting period.

The herbicide mix to be used is Weedmaster Duo® (360g/L glyphosate) or Roundup Biactive® (360g/L glyphosate), diluted at a rate of 1L per 100L of water, plus a Goal “spike” at a rate of 50ml per 100L of water. The goal spike is recommended to accelerate brown out and visibility of sprayed area.

Inspect the site to analyse the effectiveness of the initial weed spraying. If control has not been 100% effective or more weeds have germinated since, then a second spray event may be needed. A second weed spray event has been incorporated into the costing for this project.

Planting should occur two to three weeks after the second weed spraying event has occurred and once the weeds are dead.

Plants should be distributed throughout in the clump (approximately 1m apart, within the 400m2 central core), according to the recommended species in each management Area (see Section 5).

Trees and shrubs should have a tree guard placed around each plant (this is not necessary for groundcovers).

It is recommended that a watering regime be put in place for at least at the initial planting stage and the following summer period.

Maintenance is critical to the success of any revegetation project, particularly where large numbers of smaller understorey species are planted. Weed control will need to be ongoing if any revegetation program is to be successful, and hence the cost estimate for revegetation below includes ongoing weed control for five years. This should be adequate to give the plants a good start, but should be revisited in future years to determine if enough weed control has been allowed for. It is also recommended that weed control should continue after the five years of this plan, and



the extent of this should be determined at the end of this plan, based on the success of the current maintenance program. Plants will need to be sourced from suppliers of indigenous native plants. Provenance seed must be collected from on site or from remnant vegetation that is as close as possible to the site. There are several current reputable suppliers in the Adelaide region that can grow healthy local provenance tubestock or envirocells readily. Accurate records of where and when seed was collected by plant suppliers should be held and a requirement of any contract to supply plants. Tubestock should be planted in the winter months, after the breaking rains have occurred. Usually June and July are the most appropriate months, however, it may need to change slightly to adapt to the season. Initial weed control should occur approximately two to three weeks before the required planting date, with care taken to avoid any scattered native understorey species that may be growing in the planting area. Revegetation should occur in areas free of indigenous species, where regeneration should be occurring or encouraged.

Broadscale Direct Seeding

Ensure weather conditions are appropriate for spraying.

Blanket spray the area (avoiding any native species, of which there should be few or none if the area has been chosen correctly).

The herbicide mix to be used is Weedmaster Duo® (360g/L glyphosate) or Roundup Biactive® (360g/L glyphosate), diluted at a rate of 1L per 100L of water, plus a Goal “spike” at a rate of 50ml per 100L of water. The goal spike is recommended to accelerate brown out and visibility of sprayed area.

Inspect the site to analyse the effectiveness of the initial weed spraying. If control has not been 100% effective or more weeds have germinated since, then a second spray event may be needed. A second weed spray event has been incorporated into the costing for this project.

Direct Seeding should occur two to three weeks after spraying has occurred once the weeds are dead. An appropriately qualified contractor will carry out this task.

Maintenance is critical to the success of any revegetation project, particularly where large numbers of smaller understorey species are planted. Weed control will need to be ongoing if any revegetation program is to be successful, and hence the cost estimate for revegetation below includes ongoing weed control for five years. This should be adequate to give the plants a good start, but should be revisited in future years to determine if enough weed control has been allowed for. It is also recommended that weed control should continue after the five years of this plan, and the extent of this should be determined at the end of this plan, based on the success of the current maintenance program. Plants will need to be sourced from suppliers of indigenous native plants. Provenance seed must be collected from on site or from remnant vegetation that is as close as possible to the site. There are several current reputable suppliers in the Adelaide region that can grow healthy local provenance tubestock or envirocells readily. Accurate records of where and when seed was collected by plant suppliers should be held and a requirement of any contract to supply plants. Tubestock should be planted in the winter months, after the breaking rains have occurred. Usually June and July



are the most appropriate months, however, it may need to change slightly to adapt to the season. Initial weed control should occur approximately two to three weeks before the required planting date, with care taken to avoid any scattered native understorey species that may be growing in the planting area. Revegetation should occur in areas free of indigenous species, where regeneration should be occurring or encouraged. All details on numbers of plants, species, strata, area to be revegetated, spacings, layout and composition of clumps has been detailed individually for each Management Area. A separate costing has also been included for each Management Area.

4.5.2 Revegetation Species List

See individual revegetation species list within Section 5.0 Description of Management Areas.



4.6 Management Activities calendar

Table 5 - Management Activities Calendar

Weeds Calendar Year

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Slashing for native grass encouragement

Slashing for Salvation Jane control

Broadleaf herbicide control

Woody weed control

Herbaceous weed control

Bushcare

Revegetation and direct seeding site preparation

Revegetation planting

Direct seeding

Revegetation Maintenance

Rabbit Control

Monitoring

Bailing of hay



5. Description of Management Areas.

Figure 1 – Location of Management Areas within the Onkaparinga Estuary.



A total of 11 Management Areas (Fig 1) have been identified within the Onkaparinga Estuary (Adelaide and Mount Lofty Ranges Natural Resources Management Board 2006). The following outlines the current condition and the management objectives within each Management Area.



5.1 Management Area 1.

Area – Approximately 21 hectares Priority - 5

Area Description and Condition. This management area has an emphasis mainly on recreation and amenity of the area occurring within the town of Old Noarlunga. The area contains areas of steep slopes that are highly modified due to the filling of soil in the past. Patches of native vegetation occur within the area including Samphire spp., patches of native grasses, scattered Eucalyptus camaldulensis (River Red Gum) along the river banks and patches of Phragmites australis (Common Reed). Vegetation within this area is in moderate to very poor condition with a variety of declared weed species common throughout the area. Many feral plant species such as Olea europaea (Olive), Lycium ferocissimum (African Boxthorn), Opuntia sp. (Prickly Pear) and Agave americana (Century Plant) occur within the outer riparian zone up to the steeps slopes zone within the reserve.

Significant Flora Species None were observed during the survey period. High Priority Weed Species Lycium ferocissimum (African Boxthorn) Pennisetum macrourum (African feather grass) Olea europaea (Olive) Opuntia sp. (Prickly Pear) Agave americana (Century Plant) Pinus halepensis (Aleppo Pine) Casuarina glauca (Swamp Oak) Foeniculum vulgare (Fennel) Schinus areira (Pepper-tree) Nicotiana glauca (Tree Tobacco) Verbena bonariensis (Purple-top Verbena) Fraxinus angustifolia (Desert Ash) Galenia sp. (Galenia) Pennisetum clandestinum (Kikuya) Piptatherum miliaceum (Rice Millet) Scabiosa atropurpurea (Scabious)



Pest Animal Species None recorded during the survey. Action Plan Priorities for Management Area 1. 1. To conserve and improve the health of native vegetation; 2. To improve biodiversity; 3. To control populations of invasive weeds; 4. To control erosion. Native Grass Patches (relates to action 1) This management area contains small patches of Austrodanthonia caespitosa, predominately along the river banks. General native grass management principles that aim to encourage the regeneration and expansion of these areas should be applied (see Section 4.4).



Revegetation (relates to actions 2 and 4) Revegetation within Management Area 1 should coincide with woody weed control along sections of steep banks to reduce erosion problems.

Table 6 - Revegetation Description for Management Area 1 (Fig 2)

Revegetation Area 6 ha

Reference community Eucalyptus porosa (Mallee Box) Woodland

% Cover outcome Trees 20%, Shrubs >1m 4%, Shrubs <1m 2%

Methods to be used Tubestock planting

Site preparation required Weed control – woody weed control (see section on weed control), spraying

Total no. of clumps and plants required

2 clumps per hectare = 12 clumps

Each clump consists of 86 trees, 48 shrubs >1m and 198 shrubs <1m.

Total of 1030 trees, 580 shrubs >1mand 2380 shrubs <1m = 3990 plants

Location and layout of planting

Locate clumps amongst existing trees or groups of trees

Avoid areas of native grasses

Clumps are to be a mix of species at the ratio detailed above

Trees and shrubs >1m to be guarded (1610 guards).

Storey Species Number

Trees Acacia pycnantha 420

Allocasuarina verticillata 300

Eucalyptus porosa 10

Melaleuca lanceolata ssp. lanceolata 100

Pittosporum angustifolium 200

Shrubs >1m Acacia paradoxa 30

Bursaria spinosa ssp. spinosa 40

Dodonaea viscosa ssp. spatulata 150

Olearia ramulosa 60

Acacia cupularis 100

Acacia agrophylla 100

Eremophylla longifolia 100

Shrubs <1m Atriplex semibaccata 330

Enchylaena tomentosa 300

Goodenia albiflora 300



Hardenbergia violacea 100

Lavatera plebeia 150

Vittadinia blackii 400

Vittadinia cuneata var cuneata 400

Vittadinia gracilis 400

Total 3990



Weed Control Objectives (relates to action 3) The following table shows the priority weeds found in this area and their distribution. See figure 2 for location and appendix 1 for appropriate methods.

Table 7 – Priority weeds occurring within Management Area 1.

Species Distribution Priority

African Boxthorn

Widespread scattered

1

African Feather Grass

Localized 1

Olive Widespread,

scattered 1

Prickly Pear Widespread

defined 1

Century Plant Widespread,

defined 1

Aleppo Pine Localised 2

Swamp Oak Localised 2

Fennel Localised 2

Pepper-tree Widespread

defined 2

Tree Tobacco Localised 2

Purple-top Verbena

Localised 2

Desert Ash Localised 3

Galenia Widespread,

scattered 3

Kikuyu Widespread,

scattered 3

Rice Millet Widespread,

scattered 3

Scabious Localised 3



Notes on weed control within Management Area 1.

As stated within the revegetation section of Management Area 1, it is suggested that control of woody weed species occuring along steep banks should coincide with the revegetation within these sections to reduce erosion problems.

Any oversized trees will need to be assessed against the Significant Trees Development Act 1993 before weed control objectives are implemented.

Desert Ash, Pepper-Tree and Swamp Oak occuring near the recreational Park within the township (see fig 2) should be felled and removed from site to reduce an eye sore within the park.

Bushcare No Bushcare sites have been suggested for Management Area 1. Monitoring It is recommended that photopoints be set up in the following different areas within Management Area 1:

in an area where dense weeds will be controlled;

in a revegetation area;

in an area to monitor erosion of the steep banks.



Figure 2 – Management Area 1 Pest Plant Distributions



Figure 3 – Management Area 1 Proposed Revegetation sites




Area – Approximately 11 hectares Priority – 6

Area Description and Condition.

This area is predominately a constructed seasonally inundated wetland which provides habitat and refuge for aquatic and migratory birds. Vegetation directly surrounding the wetland has been vegetated with indigenous plant species such as Acacia pycnantha (Golden Wattle), Dodonaea viscose (Sticky Hopbush) and Allocasuarina verticillata (Drooping She-oak), this revegetation is considered to be in moderate condition but is under threat by the invasion of weed species such as Tamarix aphylla (Athel pine), Galenia pubescens. (Galenia) and Pennisetum clandestinum (Kikuyu). Vegetation surrounding the wetland contains areas of planted Eucalyptus porosa (Mallee Box) and a shelter belt of large Tamarix aphylla (Athel pine).

Significant Flora Species None were observed during the survey period. High Priority Weed Species Lycium ferocissimum (African Boxthorn) Olea europaea (Olive) Tamarix aphylla (Athel Pine) Casuarina glauca (Swamp Oak) Senecio pterophorus var pterophorus (African Daisy) Galenia sp. (Galenia) Pennisetum clandestinum (Kikuyu) Heliotropium europaeum (Potatoes weed)

Pest Animal Species None recorded during the survey.

Action Plan Priorities for Management Area 2 1. To conserve and improve the health of previous revegetation efforts;

2. To control populations of invasive weeds. Native Grass Patches



No native grasses were observed within this management area during the survey period. Revegetation As part of this management action plan, revegetation has not been recommended in this area. This is due to the existing revegetation efforts already completed. Weed Control Objectives (relates to Actions 1 and 2) The following table shows the priority weeds found in this area and their distribution. See figure 4 for location and appendix 1 for appropriate methods.



African Boxthorn

Widespread defined

1

Olive Widespread

defined 1

Athel Pine Widespread,

defined 1

Swamp Oak

Widespread, defined

2

African Daisy

Widespread, scattered

2

Galenia Widespread,

scattered 3

Kikuyu Widespread,

scattered 3

Potato weed


3

Bushcare No Bushcare sites have been suggested for Management Area 2.



Monitoring It is recommended that photopoints be set up in the following different areas within this zone:

in an existing revegetation area.



Figure 4 – Management Area 2 Pest Plant Distributions.




Area - Approximately 12 hectares Priority – 8

Area Description and Condition This area is located on the eastern side of the Onkaparinga River just above South Road. Vegetation is mostly comprised of planted non-local Eucalyptus and Exotic grasslands. Very little native vegetation occurs within this area and is considered to be in poor condition with many problematic weed species being common throughout the site such as Olea europaea (Olive) and Casuarina galuca (Swamp Oak).

Significant Flora Species Vittadinea blackii (Narrow-leaf New Holland Daisy) - Rare within the Southern Lofty Botanical Region. High Priority Weed Species Lucium ferocissimum (African Boxthorn) Olea europaea (Olive) Pinus halepensis (Aleppo Pine) Foeniculum vulgare (Fennel) Casuarina glauca (Swamp Oak) Fraxinus angustifolia (Desert Ash) Pennisetum clandestinum (Kikuyu) Maribium vulgare (Horehound) Asphodelus fistulosus (Onion weed) Galenia pubescens (Galenia) Heliotropium europaeum (Potato weed) Scabiosa atropurpurea (Scabious) Pest Animal Species

Hare (Lepis capensis) – One individual observed during the survey period. Action Plan Priorities for Management Area 3. 1. To conserve and improve the health of native vegetation; 2. To improve biodiversity;



3. To control populations of invasive weeds.

Native Grass Patches (relates to Action 1) Native grass species such as Danthonia caespitosa (Wallaby grass) and Stipa nodosa (Spear grass) occur scattered throughout the site particulary within patches of planted non-local Eucalypts. General native grass management principles that aim to encourage the regeneration and expansion of these areas should be applied (see Section 4.4).

Revegetation (Relates to Action 2)

Table 9 - Revegetation Description for Management Area 1 (Fig 5)



% Cover outcome Trees 20%, Shrubs >1m 4%, Shrubs <1m 2%

Methods to be used Tubestock planting

Site preparation required Weed control – woody weed control (see section on weed control), spraying

Total no. of clumps and plants required


Each clump consists of 82 trees, 42 shrubs >1m and 207 shrubs <1m

Total of 494 trees, 250 shrubs >1m and shrubs 1240 <1m = 1984 plants


Locate clumps amongst existing trees or groups of trees



Trees and shrubs >1m to be guarded (744 guards)

Number

Storey Species




Melaleuca lanceolata ssp. lanceolata 30


Shrubs >1m Acacia paradoxa 10

Bursaria spinosa ssp. Spinosa 20



Dodonaea viscosa ssp. Spatulata 90

Olearia ramulosa 30

Acacia acinacea 50

Eremophylla longifolia 50





Lavatera plebeia 100




Total 1984



Weed Control Objectives (relates to Actions 1 and 3) The following table shows the priority weeds found in this area and their distribution. See figure 5 for location and appendix 1 for appropriate methods.



African Boxthorn

Localised 1

Olive Widespread,

scattered 1

Allepo pine Localised 1

Fennel Localised 1

Swamp Oak

Localised 1

Desert Ash Localised 2

Kikuyu Widespread,

defined 2

Horehound Widespread,

scattered 3

Onion Weed


3

Galenia Widespread,

scattered 3

Potato Weed


3

Scabious Widespread,

scattered 3

Bushcare Bushcare activities within Management Area 3 should be focused around the known population of Vittadinea blackii (Narrow-leaf New Holland Daisy). See section 4.1.3 and Appendix 1 for appropriate methods.

Monitoring

It is recommended that a photopoint be set up in the following area within Management Area 3:

In a revegetation area.



Figure 5 - Management Area 3. Pest Plant Distribution, Rated Species and Proposed Revegetation Sites.




Area – Approximately 110 hectares Priority – 9

Area Description and Condition. This area has been extensively modified through the clearing of vegetation, grazing and the planting of non-local native vegetation including large stands of Eucalyptus cladocalix (Sugar Gum) and Eucalyptus porosa (Mallee Box). Native vegetation within the site is considered to be in poor condition with species such as Enchyleana tomentosa (Ruby Salt Bush), Danthonia caespitosa (Wallaby grass) and Stipa spp. occur scattered throughout the planted non-local vegetation, an area containing a Intertidal Samphire community occurs within this management area. Many problematic weeds also occur commonly throughout the site including species such as Lycium ferocissimum (African Boxthorn), Olea europaea (Olive) and Cynara cardunculus (Artichoke Thistle). Significant Flora Species Vittadinia blackii (Narrow-leaf New Holland Daisy) Rare within the Southern Lofty Botanical Region.

High Priority Weed Species Lycium ferocissimum (African Boxthorn) Olea europaea (Olive) Agave americana (Century Plant) Cynara cardunculus (Artichoke Thistle) Limonium companyonis (Sea-lavender) Casuarina glauca (Swamp Oak) Marrubium vulgare (Horehound) Asphodelus fistulosus (Onion Weed) Galenia pubescens (Galenia) Piptatherum miliaceum (Rice Millet) Pest Animal Species Rabbit (Oryctolagus cuniculus) – One individual and one active warren within the patch of planted Eucalyptus cladocalyx (Sugar Gum) was observed during the survey.



Action Plan Priorities for Management Objectives within Area 4. 1. To conserve and improve the health of native grasses 2. To improve biodiversity; 3. To control populations of invasive weeds.

Native grass patches – relates to Action 1 Small patches of Austrodanthonia caespitosa (Wallaby grass) and Austrostipa spp. occur scattered throughout most of management area 4, predominately occurring within the Exotic grassland vegetation association were no slashing occurs. General native grass management principles that aim to encourage the regeneration and expansion of these areas should be applied (see Section 4.4).

Revegetation – relates to Action 2

Site 1 (Fig 7)

Table 11 - Revegetation description for Management Area 4, Site 1.

Revegetation Area 13.5 ha

Reference community Tubestock Planting - Eucalyptus porosa (Mallee Box) Woodland

Direct seeding – Chenopod species

% Cover outcome Trees 18%, Shrubs >1m 2%

Methods to be used Direct Seeding and Tubestock Planting

Site preparation required Weed control – spraying

Total no. of clumps, plants or direct seeding required

10 ha of direct seeding

Total of 1860 trees (138 per hectare) and 510 shrubs >1m (38 per hectare) = 2370 plants


Direct seeding to cover entire zone

Trees and shrubs to be planted amongst direct seeding in second year after direct seeding

Locate plants in areas where no native plants have germinated

All Tubestock are to be guarded



Table 12 - Site 1 revegetation species list





Melaleuca lanceolata ssp. Lanceolata 300


Shrubs >1m Bursaria spinosa ssp. spinosa 30


Olearia ramulosa 140

Total 2370

Table 13 - Site 1 direct seeding mix

Species Kg seed/ha

Rhagodia candolleana ssp. candolleana 2.5

Atriplex semibaccata 2

Atriplex suberecta 2

Enchylaena tomentosa 2.5

Vittadinia blackii 0.05

Vittadinia cuneata var cuneata 0.05

Vittadinia gracilis 0.05

Einadia nutans 0.5

Sub-Total 9.65

Total 10 ha 96.5



Site 2. (Fig 7)

Table 14 - Revegetation description for Management Area 4, Site 2.


Reference communtity Tubestock Planting - Eucalyptus porosa

(Mallee Box) Woodland

Direct seeding – Chenopod species

% Cover outcomes Trees 18 %, Shrubs >1m 2%

Methods to be used Direct Seeding and Tubestock Planting



7 ha of direct seeding

Total of 1380 trees ( 138 per hectare) and 380 shrubs >1m (38 per hectare) = 1760 plants

Location and layout of planting Direct seeding to cover entire zone

Trees and shrubs to be planted amongst direct seeding in second year after direct seeding

Locate plants in areas where no native plants have germinated

All Tubestock are to be guarded

Table 15 - Site 2 revegetation species list.









Olearia ramulosa 110

Total 1760



Table 16 - Site 2 direct seeding mix.

Species Kg seed/ha

Rhagodia candolleana ssp. candolleana 2.5


Atriplex suberecta 2

Enchylaena tomentosa 2.5

Vittadinia blackii 0.05

Vittadinia cuneata var cuneata 0.05

Vittadinia gracilis 0.05

Einadia nutans 0.5

Sub-Total 9.65

Total 10 ha 69.5



Weed Control Objectives (Relates to action 3). The following table shows the priority weeds found in this area and their distribution. See figure 6 for location and appendix 1 for appropriate methods.

Table 17 - Priority weeds occurring within Management Area 4.


African Boxthorn

Localised 1

Olive Widespread

defined 1

Century Plant

Localised 1

Sea-lavender

Localised 1

Swamp-oak

Localised 2


scattered 3

Onion Weed


3

Galenia Widespread,

scattered 3


scattered 3



Bushcare Bushcare should be focused around known location of Vittadinia blackii (Narrow-leaf New Holland Daisy) within Management Area 4. See section 4.1.3 and Appendix 1 for appropriate methods.

Monitoring It is recommended that a photopoint be set up in the following area within Management Area 4:

In a revegetation area.

In a bush care site.



Figure 6 – Management Area 4 Pest Plant Distributions, Rated Species Distribution.



Figure 7 – Management Area 4 Proposed Revegetation sites, Proposed Bushcare Site.





Area Description and Condition This area is mainly comprised of constructed ephemeral wetlands and large areas of planted non-local Eucalyptus and Melaluecas that have many problematic weed species occurring commonly throughout the site. Species such as Casuarina glauce (Swamp Oak) have had control efforts put in place, however follow up control of the Swamp Oak population within this area is urgent to effectively removal the species. Direct seeding and small planted revegetation efforts have undergone within this management area mainly within areas of exotic grassland and non-local Eucalyptus sites with various success rates. Existing native vegetation occurs scattered throughout the site mainly due to revegetation and direct seeding efforts but are considered to be underthreat by invasion of weed species such as Echium plantagineeum (Salvation Jane), Cynara cardunculus (Artichoke Thistle) and Pennisetum macrourum (African feather grass). Planted Eucalyptus camaldulensis (River Red Gum) also occur scattered along the river bank.

Significant Flora Species Gahnia filum (Chaffy Saw-sedge) – Rare within the Southern Lofty Botanical Region. High Priority Weed Species Lycium ferocissimum (African Boxthorn) Casuarina glauca (Swamp Oak) Echium plantagineum (Salvation Jane) Foeniculum vulgare (Fennel) Ricinus communis (Caster Oil) Pennisetum macrourum (African feather grass) Acacia cyclops (Western Coastal Wattle) Senecio pterophorus (South African Daisy) Cyncara cardunculus (Artichoke Thistle) Galenia pubescense (Galenia) Pennisetum clandestinum (Kikuyu) Piptatherum miliaceum (Rice Millet) Asphodelus fistulosus (Onion Weed) Scabiosa atropurpurea (Scabious) Heliotropium europaeum (Potato weed) Mesembryanthemum crystallinum (Ice Plant) Conyza bonariensis (Fleabane)



Pest Animal Species Hare – Three individuals were observed with in patches of planted Non-local Eucalyptus. Rabbits – One individual was observed in a patch of Eucalyptus camaldulensis (River Red Gum). Action Plan Priorities for Management Area 5

To conserve and improve the health of native vegetation;

To improve past revegetation efforts;

To control populations of invasive weeds.

Native Grass Patches None were observed during the survey period. Revegetation No revegetation sites have been recommended for Management Area 5 due to revegetation efforts put into operation within recent years through Direct Seeding and Plantings. The following weed control objectives will further improve these previous revegetation efforts. Weed Control Objectives (relates to actions 1, 2 and 3) In recent years there has been an attempt to control the population of Casuarina glauce (Swamp Oak) within Management Area through a cut and swab method. However the majority of individuals are now re-shooting, it has been identified that follow up control of the re-shooting Swamp Oak is the highest priority within Management Area 5.

The following table shows the priority weeds found in this area and their distribution. See figure 8 for location and appendix 1 for appropriate methods.





African Boxthorn

Widespread, defined

1

Swamp Oak

Widespread, defined

1

Salvation Jane

Widespread, defined

1

Fennel Widespread,

scattered 1

Caster Oil Localised 1

African Feather grass

Localised 1

Artichoke Thistle


2

Kikuyu Widespread,

scattered 3


scattered 3

Onion weed


3


scattered 3

Scabious Widespread,

scattered 3

Potato weed


3

Ice plant Localised 3

Flea-bane Widespread,

scattered 3



Bushcare Bushcare should be focused around population of Gahnia filum (Chaffy Saw-sedge) within Management Area 5. See section 4.1.3 and Appendix 1 for appropriate methods. Monitoring It is recommended that a photopoint be set up in the following area within Management Area 5:

In a revegetation area;

In the Casuarina glauce vegetation association;



Figure 8 – Management Area 5, Pest Plant Distributions.




Area – Approximately 47 hectares Priority – 10 Area Description and Condition This management area comprises flat land that is well above the flood level and has been extensively modified through land clearing and grazing in the past with very little remnant vegetation remaining. A large stand of Eucalyptus porosa (Mallee Box) may have been originally planted or has regenerated, small native grass patches occur scattered throughout this woodland as well as a small patch of Pittosporum angustifolium (Native Apricot) which is rated as rare within the Southern Lofty Botanical Region. A large area of planted non-local Eucalyptus species also occurs within this area aswell as areas of exotic grassland.

Significant Flora Species Pittosporum angustifolium (Native Apricot) - Rare within the Southern Lofty Botanical Region.

High Priority Weed Species Lycium ferocissimum (African Boxthorn)

Cynara cardunculus (Artichoke Thistle) Echium plantagineum (Salvation Jane) Marrubium vulgare (Horehound) Olea europaea (Olive) Solanum elaeagnifolium (Silver-leaved nightshade) Acacia cyclops (Western Coastal Wattle) Asphodelus fistulosus (Onion weed) Galenia secunda (Galenia) Galenia pubescens var. pubescens (Galenia) Pinus halepensis (Aleppo Pine) Piptantherum miliaceum (Rice Millet) Lagunaria patersonii (Pyramid Tree)

Pest Animal Species Hares (Lepis capensis) – one individual observed.



Action Plan Priorities for Management Area 6.

1. To conserve and improve the health of native vegetation.

2. To improve biodiversity.

3. To control populations of invasive weed populations.

Native Grass Patches (relates to action 1) Native grasses such as Danthonia caespitosa (Wallaby grass) and Stipa spp. (Spear grass) were identified scattered primarily within the Eucalyptus porosa (Mallee Box) Woodland. General native grass management principles that aim to encourage the regeneration and expansion of these areas should be applied (see Section 4.4).

Revegetation (relates to action 2)

As management area 6 is located close to the Seaford Meadows development, the concept for revegetation for this area is to plant a high density of indigenous plant species close to areas that are more frequented by human activity. The overall concept is to improve biodiversity within the area with a focus on amenity (see figure 1).



Table 19 - Revegetation Description for Management Area 6.


Methods to be used Tubestock Planting


% Cover outcome Trees 20%, Shrubs >1m 4%m, Shrubs <1m 1%, Perrenial grasses 0.05%




No direct seeding

Each clump consists of 85 trees, 52 shrubs >1m, 119 shrubs <1m and 22 perennial grasses.

Total of 1530 trees, 945 shrubs >1m, 2142 shrubs <1m and 405 perennial grasses = 5022 plants


See fig 9. for location of planting sites




Number

Storey Species






Myoporum insulare 360

Shrubs >1m Bursaria spinosa ssp. Spinosa 72


Nitraria billardierei 18

Olearia ramulosa 90

Rhagodia candolleana ssp. Candolleana 180

Acacia cupularis 180

Acacia acinacea 180



Eutaxia microphylla 99





Lotus australis 180

Maireana brevifolia 99

Scaevola albida 99




Perennial Grasses

Aristida behriana 90

Austrodanthonia spp. 90

Themeda triandra 225

Total 5022



Weed Control Objectives (Relates to action 3). The following table shows the priority weeds found in this area and their distribution. See figure 9 for location and appendix 1 for appropriate methods.



African Boxthorn

Widespread defined

1

Artichoke Thistle

Localised 1

Silver-leaf Nightshade

Localised 1

Olive Widespread

defined 1

Salvation Jane

Widespread, defined

1

Pyramid Tree

Widespread defined

1

Aleppo Pine

Localised 2

Western Coastal Wattle

Widespread, defined

2


scattered 2

Onion Weed


2

Galenia Widespread,

scattered 2


scattered 2



Bushcare Bushcare should be focused around the known populations of Pittosporum angustifolium (Native Apricot) within Management Area 6. See section 4.1.3 and Appendix 1 for appropriate methods. Monitoring It is recommended that a photopoint be set up in a revegetation clump within this management area.



Figure 9 – Management Area 6, Pest Plant Distribution, Rated Species, Proposed Revegetation Site.





Area Description and Condition This area consists of a constructed ephemeral wetland surrounded by a mix of non-local Eucalyptus species and Melaleucass. Very little native vegetation occurs within this area with species such as Enchylaena tomentosa (Ruby Saltbush), Rhagodia candolleana (Sea-berry Saltbush) and Dianella revoluta (Black-anther Flax-lily) occur scattered throughout the area and is considered to be in poor condition, with many declared and environmental weeds (see High Priority Weed Species) occurring commonly throughout this management area. Areas of open exotic grassland also occur.

Significant Flora Species None were observed during the survey period. High Priority Weed Species Lycium ferocissimum (African Boxthorn) Foeniculum vulgare (Fennel) Olea europaea (Olive) Tamarix aphylla (Athel Pine) Acacia cyclops (Western Coastal Wattle) Marrubium vulgare (HoreHound) Galenia sp. (Galenia) Piptatherum miliaceum (Rice Millet) Pennisetum clandestinum (Kikuyu)

Pest Animal Species None were recorded during the survey. Action Plan Priorities for Management Area 7. 1. To Conserve and improve the health of native vegetation; 2. To improve biodiversity; 3. To control populations of invasive weeds.



Native Grass Patches None were recorded within Management Area 7.



Revegetation – (relates to action 2)

Table 21 – Revegetation Description for Management Area 7



% Cover outcome Trees 20%, Shrubs >1m 4%m, Shrubs <1m 1%, Perrenial grasses 0.05%

Methods to be used Tubestock Planting



No direct seeding


Each clump consists of 10 trees, 50 shrubs and 300 groundcovers/ low shrubs.

Total of 170 trees, 105 shrubs >1m, 238 shrubs <1m and 45 perennial grasses = 558 plants





Number

Storey Species



Eucalyptus porosa 5



Myoporum insulare 40



Nitraria billardierei 2

Olearia ramulosa 10

Rhagodia candolleana ssp. Candolleana 20

Acacia cupularis 20

Acacia acinacea 20



Eutaxia microphylla 11





Lotus australis 20

Maireana brevifolia 11

Scaevola albida 11




Perennial Grasses

Aristida behriana 10

Austrodanthonia spp. 10

Themeda triandra 25

Total 558



Weed Control Objectives – (relates to Actions 1 and 3) The following table shows the priority weeds found in this area and their distribution. See figure 10 for location and appendix 1 for appropriate methods.



African Boxthorn

Localised 1

Fennel Localised 1

Olive Widespread,

scattered 1

Athel pine Widespread,

defined 2

Western Coastal Wattle


2

Horehound Widespread

scattered 3

Galenia Widespread

scattered 3

Rice Millet Widespread

scattered 3

Kikuyu Widespread

scattered 3



Bushcare No Bushcare sites have been suggested for Management Area 7. Monitoring It is recommended that photopoints be set up in the following different sites within this Management Area:

in a Constructed Ephemeral Wetland;

in a revegetation area.



Figure 10 – Management Area 7, Pest Plant Distributions, Proposed Revegetation Sites.





Area Description and Condition This area is considered to be an important area of conservation having relatively intact areas of interdital and supratidal Samphire communities within the Oxbow Lagoon. Vegetation within the intertidal and supratidal comommunities are considered to be in good to very good condition. Vegetation surrounding the Samphire communities are made up of large areas of planted non-local Eucalyptus species that areconsidered to be in poor condition within many problematic weeds such as Olea europaea (Olive), Galenia pubescens. (Galenia) and Marrubium vulgare (HoreHound) scattered throughout the site.

Significant Flora Species Gahnia filum (Chaffy Saw-sedge) - Rare within the Southern Lofty Botanical Region.

High Priority Weed Species Lycium ferocissimum (African Boxthorn) Olea europaea (Olive) Limonium companyonis (Sea-lavender) Asphodelus fistulosus (Onion Weed) Galenia pubescens. (Galenia) Heliotropium europaeum (Potato Weed) Piptatherum miliaceum (Rice Millet) Marrubium vulgare (HoreHound)

Pest Animal Species None were observed during the survey period. Action Plan Priorities for Management Area 8. 1. To conserve and improve the health of native vegetation; 2. To improve biodiversity; 3. To control populations of invasive weeds.



Native Grass Patches None were observed during the survey period. Revegetation (relates to Action 2) A proposed area has been identified within Management Area 8 (Fig 11). It is suggested that a mix of Chenopods be planted in this area. Further consultation will be undertaken to achieve a revegetation species list and composition for this revegetation site.



Weed Control Objectives – (relates to Actions 1 and 3) The following table shows the priority weeds found in this area and their distribution. See figure 11 for location and appendix 1 for appropriate methods.



African Boxthorn

Localised 1

Olive Widespread,

scattered 1

Sea lavender

Widespread, defined

2

Onion weed


3

Horehound Widespread

scattered 3

Galenia Widespread

scattered 3

Potato weed


3

Rice Millet Widespread

scattered 3

Bushcare It is suggested that Bushcare be undertaken in the Intertidal Samphire Community focusing around populations of Gahnia filum (Chaffy Saw-sedge) (Figure 11). See section 4.1.3 and Appendix 1 for appropriate methods. Monitoring It is recommended that photopoints be set up in the following different sites within this Management Area:

in a revegetation area;

in a Samphire community.



Figure 11 – Management Area 8 Pest plant distribution and proposed revegetation site.




The Christies Beach Wastewater Treatment Plant (WWTP) Upgrade Project (2007) is currently being implemented within management area 9. Area 9 is therefore not included within this Management Action Plan.



Figure 12 - Management Area 9.




Area – Approximately 11 hectares Priority - 1 Area Description and Condition This Management Area being at the Commercial Road Bridge down stream to the footbridge. The area is considered to be an important area for conservation begin visited by many bird species, including migratory waders. The area is densely vegetated with Samphire communities and is considered to be in very good condition with very little invasion by problematic weeds.

Significant Flora Species Gahnia filum (Chaffy Saw-sedge) – Rare within the Southern Lofty Botanical Region. High Priority Weed Species Lycium ferocissimum (African Boxthorn) Agave Americana (Century Plant) Foeniculum vulgare (Fennel) Pest Animal Species None were recorded during the survey. Action Plan Priorities for Management Area 10. 1. To control populations of invasive weeds. Native Grass Patches None were observed within Management Area 10.

Revegetation Revegetation has not been recommended within this area. This is due to the relatively intact and good condition native vegetation occurring within Management Area 10.



Weed Control Objectives (relates to Action 1) The following table shows the priority weeds found in this area and their distribution. See figure 13 for location and appendix 1 for appropriate methods.



African Boxthorn

Localised 1

Century Plant

Localised 1

Fennel Localised 1

Bushcare Bushcare should be undertaken within the Intertidal Samphire Communities focusing around populations of Gahnia filum (Chaffy Saw-sedge). See section 4.1.3 and Appendix 1 for appropriate methods. Monitoring It is recommended that photopoints be set up in the following different areas within Management Area 10:

in an area where problematic weeds are to be controlled;

in an area of remnant vegetation.



Figure 13 – Management Area 10, Pest Plant Distributions, Proposed Bushcare Site.




Area – Approximately 13.5 hectares Priority - 2 Area Description and Condition This Management Area is on the northern side of the Commercial Road Bridge. The area has an emphasis on conservation, being an important refuge for birds. Native Vegetation within the area includes patches of Samphire communities and Gahnia filum (Chaffy Saw-sedge) that are considered to be in moderate to good condition. Many problematic weeds occur commonly scattered throughout the site such as Lycium ferocissimum (African Boxthorn), Olea europaea (Olive) and Foeniculum vulgare (Fennel) (see section on High Priority Weeds).

Significant Flora Species Gahnia filum (Chaffy Saw-sedge) – Rare within the Southern Lofty Botanical Region. High Priority Weed Species Lycium ferocissimum (African Daisy) Olea europaea (Olive) Limonium companyonis (Sea-Lavender) Tamerix aphylla (Athel Pine) Phyllostachys aurea (Bamboo) Prunus sp. (Fruit Tree) Galenia sp. (Galenia) Pennisetum clandestinum (Kikuyu) Piptatherum miliaceum (Rice Millet)

Pest Animal Species None were recorded during the survey period. Action Plan Priorities for Management Area 11. 1. To conserve and improve the health of native vegetation; 2. To control populations of invasive weeds.



Native Grass Patches None were recorded within the survey area. Revegetation Revegetation has not been recommended within this area. This is due to the relatively intact and good condition of native vegetation occurring within Management Area 11.



Weed Control Objectives (relates to Actions 1 and 2) The following table shows the priority weeds found in this area and their distribution. See figure 14 for location and appendix 1 for appropriate methods.



African Boxthorn

Localised 1

Olive Widespread,

defined 1

Sea-lavender

Widespread, defined

1

Athel Pine

Localised 1

Bamboo Localised 2

Fruit Tree

Localised 3

Galenia Widespread,

scattered 3

Kikuyu Widespread,

scattered 3

Rice Millet


3

Bushcare Bushcare should be undertaken within the Intertidal Samphire Communities focusing around populations of Gahnia filum (Chaffy Saw-sedge). See section 4.1.3 and Appendix 1 for appropriate methods.

Monitoring It is recommended that photopoints be set up in the following different areas within Management Area 10:

in an area of Bushcare site.



Figure 14 – Management Area 11, Pest Plant Distributions.



6. References

City of Onkaparing (2005). Biological Diversity Strategy & Action Plan 2006-2010. Strategy and Policy Department. Dashorst, G.R.M. and Jessop, J.P. (1998). Plants of the Adelaide Plains and Hills (second edition). The Botanic Gardens of Adelaide and State Herbarium. DEH (2005). Onkaparinga Estuary Information Package. Environmental and Biodiversity Services (2006) Gawler Buffer East (Stage1) Native Vegetation Action Plan. Urban Forest Million Tree Program, DEH. Environmental and Biodiversity Services (2007) St. Kilda Antenna Fields Action Plan. Urban Forest Million Tree Program, DEH. Hydro Tasmania Consulting and Eco Management Services (2006). Onkaparinga Estuary Rehabilitation Action Plan. A joint initiative of the Adelaide and Mount Lofty Ranges Natural Resources Management Board, the Department for Water Land and Biodiversity. Jessop, J.P. and Toelken, H.R. (Eds) (1986). Flora of South Australia Parts 1-4, South Australian Government Printer, Adelaide. Nature Conservation Society (2005) Guide to Bushland Monitoring Neagle, N. (1995). An Update of the Conservation Status of the Major Plant Associations of South Australia, Department of Environment and Natural Resources, Adelaide. Nicolle, D. (1997). Eucalypts of South Australia. Lane Print Group. Prescott, A. (1988). It’s Blue with Five Petals: Wildflowers of the Adelaide Region.

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