ECOLOGICAL RESTORATION PLAN
FOR PIHA BEACH RESERVES,
PIHA
Ecological Restoration Plan for Piha Beach Reserves, Piha
Contract Report No. 3014
Project Team:
Nick Goldwater - Field survey, report compilation.
Nick Ranger, Shona Myers - Technical review and advice.
Prepared for:
Auckland Council
Private Bag 92-303
Auckland 1142
November 2012
AUCKLAND OFFICE: 97A MT EDEN ROAD, MT EDEN, AUCKLAND 1023
P.O. BOX 46 299, HERNE BAY, AUCKLAND 1001, Ph 09-377-4886; Fax 09-377-4889
HEAD OFFICE: 99 SALA STREET, P.O. BOX 7137, TE NGAE, ROTORUA
Ph 07-343-9017; Fax 07-343-9018, email [email protected], www.wildlands.co.nz
CONTENTS
1.
INTRODUCTION
1
2.
PROJECT OBJECTIVES
2
3.
METHODOLOGY
3.1
Environmental pest plant survey
3.2
Planting
3.3
Pest animals
2
2
3
3
4.
ECOLOGICAL CONTEXT
3
5.
PROJECT AREAS
5.1
North Piha Esplanade
5.2
Les Waygood Park
5.3
Piha Esplanade Reserve
5.4
North Piha Strand
5.5
Piha Domain
5.6
South Piha Road Reserve
4
4
4
4
5
5
5
6.
ENVIRONMENTAL PEST PLANTS
6.1
Environmental pest plant control priorities
5
5
7.
PEST PLANT MANAGEMENT RECOMMENDATIONS
7.1
Overview
7.2
Priority pest plants
7.3
Provenance of Pohutukawa and Other Planted Species
7.4
North Piha Esplanade
7.5
Les Waygood Park
7.6
Piha Esplanade Reserve
7.7
North Piha Strand
7.8
Piha Domain
7.9
South Piha Road Reserve
7
7
8
10
10
10
11
11
12
12
8.
PLANTING RECOMMENDATIONS
8.1
Overview
8.2
Spinifex and pingao
8.1
North Piha Esplanade
8.2
Les Waygood Park
8.3
Piha Esplanade Reserve
8.4
North Piha Strand
8.5
Piha Domain
13
13
13
14
15
17
17
18
9.
PEST ANIMAL CONTROL
9.1
Rabbits
9.2
Predators
19
19
20
© 2012
Contract Report No. 3014
© 2012
Contract Report No. 3014
10.
MONITORING
20
11.
TIMING
20
REFERENCES
22
APPENDICES
1.
Figures
2.
Site photographs
3.
List of environmental pest plant species recorded from the project area
4.
List of vascular plant species for Piha Reserves, 2011-2012
5.
Recommended herbicide treatments
24
35
40
41
45
© 2012
Contract Report No. 3014
Reviewed and approved for release by:
__________________________
Shona Myers
Senior Ecologist, Manager (Auckland office)
Wildland Consultants Ltd
 Wildland Consultants Ltd 2012
This report has been produced by Wildland Consultants Ltd for Auckland Council. All
copyright in this report is the property of Wildland Consultants Ltd and any unauthorised
publication, reproduction, or adaptation of this report is a breach of that copyright.
© 2012
Contract Report No. 3014
1.
INTRODUCTION
Auckland Council commissioned Wildland Consultants Ltd to develop an ecological
restoration plan for six Piha Beach reserves: North Piha Esplanade, Piha Esplanade
Reserve, Les Waygood Reserve, North Piha Strand, Piha Domain and Piha South
Road Reserve. Ecological management plans have recently been prepared for the
adjacent Les Waygood Reserve and North Piha Strand (Wildland Consultants Ltd
2011a and 2011b). These existing reports have been combined with management
plans for the four remaining reserves to create a master ecological restoration plan for
Piha Beach.
Piha Beach lies within the Waitakere Ecological District. The rugged Waitakere west
coast is characterised by a rocky coastline and significant dune areas including at
Piha, Whatipu and Te Henga. The wider Piha catchment contains a continuous
sequence of mature vegetation from coastal, through to alluvial flat, rugged hill
country, and high relief (Denyer et al. 1993). The Piha Coastcare Group has been
undertaking dune restoration for a number of years.
In the master plan, environmental pest plant species within the project areas have been
identified and their distribution and abundance mapped and described. An
environmental pest plant management programme has been prepared, as well as an
indigenous planting plan that can be implemented following environmental pest plant
control.
In the preparation of this report, some guidance has been taken from the Piha
Reserves Management Plan, which was compiled by Waitakere City Council in 1999.
The plan recognises the importance of controlling pest plant and animal species
throughout the reserves. The four key policies contained in the plan are as follows:
(i) Control, and where possible, eradicate pest plants and animals.
(ii) Prioritise pest plant and animals for removal or control, and target areas that are
particularly sensitive to pest plant and animal pests and areas where eradication of
such pests is still possible.
(iii) Encourage adjacent land users to control pest plants and animals on their
land to reduce invasion into the reserves.
(iv) Pest plants will be controlled in accordance with Council’s current herbicide
policy. Minimisation of herbicide use should be ensured by use of manual control
where feasible, and by the use of targeted control methods, such as drilling and
injecting, or cutting and painting pest plants. Where herbicides are used, the
lowest toxicity herbicide available should be used.
© 2012
1
Contract Report No. 3014
2.
PROJECT OBJECTIVES

Map the distribution and density of environmental pest plants in all six reserves.

Identify and recommend areas for planting.

Prepare plant schedules of suitable species.

Compile a staged programme of environmental pest plant control, planting and
pest animal control.

Outline a recommended approach for future monitoring.
3.
METHODOLOGY
3.1
Environmental pest plant survey
Field surveys for environmental pest plants were undertaken at Les Waygood Park
and North Piha Strand on 22 November 2011. A field survey of the remaining four
reserves was undertaken on 18 September 2012. Environmental pest plants are
introduced species that threaten the ecological processes and values within the area
where they are present. Field survey methods were based on previous environmental
pest plant inventories undertaken by Wildland Consultants Ltd (2011a). The field
survey involved walking through the project area identifying and recording location,
distribution and density of environmental pest plants. The GPS locations of selected
pest plant infestations were recorded where it was deemed necessary to ensure the
control/monitoring of isolated pest plant populations. During the survey, particular
attention was given to open dune areas, bush margins, stream margins, exposed banks,
and especially clearings within the canopy as these areas are most vulnerable to
environmental pest plant invasion/reinvasion.
Environmental pest plant distributions and densities were mapped in the field onto
hard copy prints of digital orthophotographs. The maps were then used for data input
into ArcGIS9.3 (GIS programme).
The location and distribution of each
environmental pest plant species were digitised. Environmental pest plant species
were labelled with their common name and a brief description of the extent of the
infestation, either as percentage cover or as the number of individuals, overlain on the
aerial photograph.
The relative priority for the control of each environmental pest plant species was
assessed based on the Auckland Regional Pest Management Strategy (ARPMS) (ARC
2007), the ecological values of the site in which the infestation occurs, the relative
vulnerability of the vegetation and habitats present, the level of threat posed by the
environmental pest plant species, and the size of the infestation. Environmental pest
plant species within each priority level (Levels 1-5 with Level 1 being the highest
priority for control) are listed in Section 4.1 below.
© 2012
2
Contract Report No. 3014
3.2
Planting
Potential planting sites and areas where planting would be advisable were identified
during the field surveys. These areas include sites where environmental pest plant
infestations will be an ongoing problem if planting is not undertaken, hind-dune areas
suitable for restoration and establishment of indigenous dune species, open areas
within existing plantings and indigenous vegetation (including foredunes), and areas
vulnerable to erosion.
3.3
Pest animals
Recommendations for the monitoring and control of pest animal species in the dunes
are outlined in Section 7 of the plan.
4.
ECOLOGICAL CONTEXT
The project area is located within the Waitakere Ecological District (ED) and are
characterised by a range of vegetation types along the low-lying dunes that extend
along most of Piha Beach (north and south ends). Most of the mid and hind-dunes
and dune slacks are highly modified, and comprise a diverse range of exotic species
including several environmental pest plants. The foredunes, however, have a high
degree of naturalness and are dominated by spinifex (Spinifex sericeus) with
occasional pingao (Ficinia spiralis). The healthy state of the foredunes has been
aided by restoration work undertaken by Council contractors and local community
groups such as Piha Coast Care. Numerous beach access paths have been created
through the reserves, some of which are fenced to discourage people walking over the
dunes.
Unconsolidated coastal dunes are a characteristic feature of the west coast of the
Waitakere ED (Denyer et al. 1993), including Piha. Dune systems have been
significantly reduced from their former extent nationally and regionally, and the intact
landform sequences of foredunes to hind-dunes present on the Waitakere west coast
have been lost elsewhere in the region. The protection of dunes is identified as a
national priority as only 11.6% of their original extent remains (Ministry for the
Environment and Department of Conservation 2007). In Auckland, only 15% of dune
vegetation remains today (Lindsay et al. 2009). The loss of active dunes since the
1950s has been greatest in Northland, Auckland and Manawatu, with a 68.4% decline
in Auckland (Hilton 2006). The restoration of dunes, including control of pest plants,
and replanting with appropriate indigenous species is a priority.
© 2012
3
Contract Report No. 3014
5.
PROJECT AREAS
5.1
North Piha Esplanade
North Piha Esplanade (c.2.7 ha) comprises a long, narrow coastal strip of low-lying
dunes that extends from the North Piha surf club to the end of Marine Parade North.
The northern half of North Piha Esplanade is characterised by dune shrubland
dominated by karo (Pittosporum crassifolium) (c.3-4 m in height) with frequent
taupata (Coprosma repens) and pohuehue (Muehlenbeckia complexa), and occasional
houpara (Pseudopanax lessonii) (Plate 1), similar to that at Les Waygood Reserve.
The shade provided by the shrubland effectively inhibits the growth of lightdemanding pest plants. The indigenous shrubland appears to be advancing towards
the foredunes and karo, in particular, is able to compete with exotic grasses such as
kikuyu (Cenchrus clandestinus), veldt grass (Ehrharta erecta) and buffalo grass
(Stenotaphrum secondatum). Despite the abundance of exotic plant species, the dune
slacks at North Piha Reserve provide habitat for a range of indigenous species such as
New Zealand spinach (Tetragonia implexicoma), knobby clubrush (Ficinia nodosa),
spinifex and pohuehue.
The foredunes are dominated by spinifex and are currently free from pest plant
infestations (Plate 2). Monkey (Takutapu) Rock, a small but prominent rock stack, is
present in the middle of the reserve. The rock is largely unvegetated, other than a few
scattered exotic herbs and grasses.
5.2
Les Waygood Park
Les Waygood Park (c.5.8 ha) comprises a range of vegetation types on low-lying
dunes at North Piha. The most interesting feature of the park is the presence of a
healthy and relatively large dune forest dominated by karo (c.3-4 m in height). This
forest is one of the largest areas of woody indigenous vegetation on stabilised dunes
on the Piha coast, and provides habitat for a range of indigenous species (Wildland
Consultants Ltd 2008). Pest plants are less able to compete in this habitat, and are
thus most abundant on the open dunes (mid and hind-dunes) and dune slacks
(Plate 3). The park also contains a small campsite that is well-maintained, and
bordered to the west by pohutukawa (Metrosideros excelsa) and other indigenous
coastal shrubs. Marawhara Stream lies along the eastern boundary, adjacent to the
campsite.
5.3
Piha Esplanade Reserve
Piha Esplanade Reserve (c.1.5 ha) comprises a small, narrow area located between the
confluence of Marawhara and Wekatahi Streams and opposite Wekatahi Reserve. It
is characterised by rank kikuyu and buffalo grass, with frequent areas of indigenous
forest and shrubland. At the northern end of the reserve there is a small but good
quality piece of forest dominated by karo and houpara with frequent kawakawa
(Macropiper excelsum), nikau (Rhopalostylis sapida) and occasional emergent
cabbage tree (Cordyline australis). The reserve is contiguous with saltmarsh
vegetation on the margins of Marawhera Stream. To the south, it includes a small
area of dunes and sandflats.
© 2012
4
Contract Report No. 3014
5.4
North Piha Strand
North Piha Strand (c.2.9 ha) is a long, narrow reserve that covers the area sometimes
known as the “middle beach” at Piha. The northern limit of the reserve is located at
the confluence of Wekatahi and Marawhera Streams. The south end of the reserve
provides direct access to Lion Rock. A car parking area is provided between the road
and sand dunes. The reserve contains low-lying mid-dunes characterised by rank
exotic grasses, vetch and pohuehue, with smaller areas of foredunes dominated by
spinifex (Plate 4).
5.5
Piha Domain
Only the part of Piha Domain to the south-west of Piha Stream (c.1.7 ha) was
surveyed for this report. The northern extent of the reserve includes stabilised dunes
dominated by kikuyu, and more natural foredunes that include a mosaic of indigenous
and exotic plant species. There is a small stabilised dune that has a wastewater
treatment area on it. This dune has been planted with pohutukawa, karo and
Tasmanian ngaio (Myoporum insulare), while open areas are characterised by veldt
grass, prairie grass (Bromus willdenowii), and patches of Solanum nodiflorum.
The southern part of the reserve comprises a large, steep hillslope that is dominated
by kikuyu and climbing asparagus (Asparagus scandens) (Plate 5).
5.6
South Piha Road Reserve
This reserve (c.0.6 ha) comprises a narrow strip along the top of the dunes at South
Piha, together with a triangular area of mown grassland bounded by Marine Parade
South. Moana Stream runs through the reserve.
6.
ENVIRONMENTAL PEST PLANTS
Twenty-four plant species were identified as environmental pest plants within the
project areas. Thirteen of these species are not identified in the Auckland Regional
Pest Management Strategy (ARPMS) (2007). The distribution and abundance of
environmental pest plant infestations are mapped in Figure 1. A full list of
environmental pest plants is provided in Appendix 3.
6.1
Environmental pest plant control priorities
Environmental pest plants are prioritised according to the three categories in the
ARPMS:
(i) Total Control Pest Plants, (ii) Containment Pest Plants, and
(iii) Surveillance Pest Plants. Two further classes of plants are identified in this
report: (iv) pest plants not currently covered by the ARPMS; and (v) exotic plant
species which are not considered a threat to the ecology of the reserve but which the
removal of would be beneficial.
Brief descriptions of the distribution of
environmental pest plant species are listed below, separated into their respective
categories.
© 2012
5
Contract Report No. 3014
(i)
Total Control Pest Plants
Total Control Pest Plants have a limited distribution or density within the
Auckland Region, or defined areas of the Region. They are considered to be
of high potential threat to the Region, and Auckland Council assumes full
responsibility for funding and implementing appropriate management
programmes for these species. The aim is to eradicate these plants from the
Region or defined areas of the Region, over a period of time, which may
exceed the life of the current ARPMS. No Total Control pest plant species
were recorded in the project area.
(ii)
Containment Pest Plants
Containment pest plants are those that are abundant in certain habitats or areas
in the region. Landowners/occupiers are required to control these plants
whenever they appear on their land. All containment pest plants are banned
from sale, propagation, distribution, and exhibition through the entire
Auckland Region. One containment pest plant species was recorded in the
project area.
gorse (Ulex europaeus)
(iii)
Boundary control (20 m in rural areas only).
Surveillance Pest Plants
Surveillance pest plants include species that have been identified as having
significant impacts on the biosecurity values of the Auckland Region.
Auckland Council seeks to prevent their establishment or spread by
prohibiting their sale, propagation, distribution, and exhibition. Nine
surveillance pest plants were recorded during the survey, all of which are
present in small infestations.









(iv)
agapanthus (Agapanthus praecox)
alligator weed (Alternanthera philoxeroides)
boneseed (Chrysanthemoides monilifera)
Cape ivy (Senecio angulatus)
climbing asparagus (Asparagus scandens)
climbing dock (Rumex sagittatus)
German ivy (Delairea odorata)
montbretia (Crocosmia ×crocosmiiflora)
Tasmanian ngaio (Myoporum insulare)
Environmental Pest Plants not Within the ARPMS
Environmental pest plant species that are present in moderate to large
infestations within the project area and are not identified in the ARPMS.
© 2012
6
Contract Report No. 3014
Fourteen species in this category was recorded in the project area.














buffalo grass (Stenotaphrum sedundatum)
fruit salad plant (Monstera deliciosa)
garden nasturtium (Tropaeolum majus)
gazania (Gazania linearis)
gladiolus (Gladiolus undulatus)
Indian doab (Cynodon dactylon)
kikuyu grass (Cenchrus clandestinus)
lupin (Lupinus arboreus)
marram (Ammophila arenaria)
radiata pine (Pinus radiata)
tree aloe (Aloe arboreus)
umbrella sedge (Cyperus eragrostis)
veldt grass (Ehrharta erecta)
vetch (Vicia sativa)
7.
PEST PLANT MANAGEMENT RECOMMENDATIONS
7.1
Overview
Due to the dynamic nature of dune systems and the sheer abundance of vetch, lupin,
kikuyu, gazania, and buffalo grass throughout the reserves, a more considered
management approach should be adopted where these pest plants are present. It
would not be possible to carry out wide scale control in the short-term, given the
prolific seed bank of fast-growing, light-demanding pest plant species that awaits any
future disturbances. Moreover, in the Piha Reserves Management Plan 2000 it was
acknowledged that widespread pest plant species such as kikuyu cannot feasibly be
eradicated from Piha.
It is recommended that priority areas for control should be established. Foredunes,
for instance, are still largely dominated by spinifex and to a lesser extent, pingao, and
should therefore be a priority for pest plant control. Both spinifex and pingao are key
indigenous sand-binding plants, and are highly vulnerable to competition from
introduced species and disturbances caused by humans and vehicles. Some pest plant
species (e.g. vetch and kikuyu) are less tolerant of the exposed conditions present on
foredunes, while others such as marram and lupin are able to advance in some parts of
the foredunes.
Vetch and kikuyu should only be controlled either in instances where it is actively
smothering indigenous vegetation or for spot spraying prior to planting, noting that
vetch is an annual so is not present year round.
Specific pest plant management recommendations are provided for each reserve.
Recommended control methods for environmental pest plants species are presented in
© 2012
7
Contract Report No. 3014
Appendix 5. It is recommended that all environmental pest plant control operations
be undertaken in line with the Agrichemical Users’ Code of Practice, NZS 8409 2004:
The Management of Agrichemicals, and any relevant Auckland Council Policies and
procedures such as herbicide reduction strategies.
Ongoing monitoring for environmental pest plants should be maintained throughout
the project area on at least an annual basis. Any other pest plant species encountered
during the annual pest plant control operation should be controlled.
7.2
Priority pest plants
Marram
Marram is currently present in relatively small quantities, often occurring in local
patches in the mid-dune and back dune areas. Of all pest plant species present at Piha,
marram has the potential to cause the most damage to the foredunes and overall dune
dynamics. Efforts should therefore be made to contain current infestations in the
short-term with a view to total eradication of marram from Piha in the medium to
long-term. Containment of a marram will involve the targeted control of outlier
populations and any new infestations in order to halt any further spread of this
species. In the longer term, the main infestation can be controlled from the edges
working towards the centre.
Lupin
Lupin is a serious pest plant of mid-dunes and dune slacks, and due to its relatively
tall stature it readily excludes almost all other dune vegetation. A concerted effort to
target lupin, combined with planting of indigenous species, will make a significant
difference to the natural state of the dunes at Piha. A strategy to contain lupin in the
short to medium-term (as per marram) should be instigated by working from the
northern and southernmost infestations, towards the middle of Piha.
The long-term view should be to effectively eradicate this pest plant from all coastal
margins of Piha. Effective eradication is achieved when all mature plants have been
controlled. Follow-up control then target seedlings and small plants so they can be
removed before they can mature and reproduce. Large plants and infestations will
likely require herbicide control, whereas small plants can easily be hand-pulled and
left in situ to rot. Local community groups can undertake this on a regular basis and
make a valuable contribution to controlling lupin. The long-term goal of effective
eradication will need significant buy-in by local residents and landowners, some of
whom are likely to have lupin growing in their gardens.
Gazania
Gazania thrives in sandy soils and withstands salt-laden winds and tolerates extreme
drought conditions, which makes it a perfect invader of coastal areas. In addition, due
to its high seed production, gazania can rapidly disperse and out-compete indigenous
plant species. This pest plant is abundant in the mid-dunes of Piha and in some places
it has managed to spread in the foredunes.
© 2012
8
Contract Report No. 3014
Containment of gazania should be undertaken in the short to medium-term in
conjunction with the control of lupin, given that both species occur in similar areas in
similar quantities.
The long-term view should be to effectively eradicate this pest plant from all coastal
margins of Piha. Most gazania infestations will require herbicide control.
Community groups, however, can be engaged to removed small isolated plants,
though any dug-out plants will have to be removed from the dune areas and safely
disposed of off-site, ensuring weed hygiene procedures are followed. Gazania is also
likely to be present as a pest plant in residential gardens, particularly lawns along
Marine Parade North. Land-owners will need to be made aware of this weed species.
Agapanthus
Agapanthus has been recognized as a priority pest plant in the Piha Reserves Draft
Management Plan (1999). Although agapanthus was only observed in very small
quantities during the surveys (proof of recent control), vigilance must be maintained
to prevent it from re-invading the dunes. It is a very resilient, shade-tolerant plant and
has the potential to spread throughout most duneland habitats, including dense karo
forest. Agapanthus is common on the Piha cliffs and in the gardens of local residents.
In a survey in 1995 it was found in 79% of gardens in Piha (WCC 1999).
Boneseed
As with agapanthus, boneseed is only present in very small quantities on the dunes of
Piha, as a result of past control works. Given its prolific seeding and rate of growth,
efforts must be made to eradicate boneseed and monitor for future incursions.
Climbing asparagus
Climbing asparagus occurs infrequently in the dunes, although there is a significant
infestation of climbing asparagus in the Piha Domain (see Section 6.7). This species
is readily dispersed by birds, and is shade-tolerant. Any infestation will continue to
act as a major source of invasion in surrounding natural areas, including forest,
shrublands, dunes and wetlands. The large infestation in Piha Domain should be
controlled in a staged operation (three to five years) in conjunction with other pest
plants such as lupin, agapanthus, and climbing dock. Staged pest plant control can
then be followed by the staged planting of coastal tree species (see Section 8.5).
Cape ivy
A large infestation of Cape ivy is present in Piha Domain, bordering a residential
property (Plate 6). This pest plant forms dense layers that can smother indigenous
vegetation. Any infestation will act as a source of dispersal to surrounding areas,
including dunes, where it has previously been recorded in small quantities (Wildlands
2011b). It would be relatively easy to control this infestation of Cape ivy in the short
to medium-term, with ongoing monitoring for new infestations required in the longer
term.
© 2012
9
Contract Report No. 3014
7.3
Provenance of Pohutukawa and Other Planted Species
Kermadec pohutukawa (Metrosideros kermadecensis), pohutukawa cultivars such as
‘Maori Princess’ and other non-ecosourced specimens are commonly planted around
New Zealand, and as such can threaten the genetic integrity of local species through
hybridization.
A general assessment of the provenance of pohutukawa and other planted species
within the reserves should be undertaken (as recommended by the Piha Coastal
Management Plan 2000). Any species or cultivars that have the potential to cross
with naturally occurring indigenous species in the Piha region, should be removed
from the reserves, and replaced with more suitable species.
7.4
North Piha Esplanade
Only one Surveillance pest plant species (agapanthus) was recorded at North Piha
Esplanade (Figure 1, Appendix 1). It is present at low densities, thus effective
eradication is feasible. Where indigenous shrubland is largely absent, the more
sheltered dune slacks and back dune areas are dominated by exotic grass species and
locally common lupin and gazania. Such species are significantly affecting the ability
of species such as spinifex and knobby clubrush to colonise these parts of the dune
system. Gladiolus and vetch are present in small quantities and should be controlled.
Wide-scale control of exotic grass species is not warranted. Control of lupin in the
mid-dune slack areas is desirable, however, followed by the planting of taller stature
indigenous plants that can compete with exotic grasses, e.g. taupata, karo and tauhinu
(Ozothamnus leptophyllus). Kikuyu should only be controlled either in instances
where it is actively smothering indigenous vegetation or for spot spraying prior to
planting.
Maintaining the weed-free nature of the foredunes and karo shrubland is a priority.
Monitoring for the presence of shade-tolerant pest plants such as climbing asparagus
and moth plant in the karo shrubland need to be undertaken on a regular basis.
GPS co-ordinates for the following isolated infestation were recorded during the field
survey:
Pest Plant Species
agapanthus
7.5
GPS Co-ordinates
NZTM E1730325 N5910590
Les Waygood Park
There were three Surveillance pest plant species recorded at Les Waygood Park
(alligator weed, boneseed, and Tasmanian ngaio), all of which are at low densities,
thus effective eradication is feasible1. The following Class (iv) plants are present in
small numbers and should be controlled: gladiolus, garden nasturtium, fruit salad
1
Potential upstream infestations of alligator weed should be investigated in order to prevent reinvasion
following control.
© 2012
10
Contract Report No. 3014
plant and tree aloe (Figure 2, Appendix 1). Marram is present in moderate densities
and should be controlled, given its ability to dominate foredune communities.
It is difficult for environmental pest plants to establish in the karo forest, which is
essentially self-sustaining. Light-demanding species such as vetch are restricted to
small clearings within the forest and, without a significant disturbance, are unlikely to
affect the long-term ecological integrity of the forest.
Monitoring of shade-tolerant species such as moth plant (Araujia hortorum) and
climbing asparagus should be undertaken, the latter of which has been previously
recorded from the site (Wildland Consultants Ltd 2008).
GPS co-ordinates for the following isolated infestation were recorded during the field
survey:
Pest Plant Species
boneseed (one shrub)
7.6
GPS Co-ordinates
NZTM E1730488 N5910198
Piha Esplanade Reserve
In the Piha Reserve Management Plan (1999) it states that control will be carried out
on prioritised pest plant species, particularly to encourage regeneration of indigenous
riparian plants. Control of some Tasmanian ngaio shrubs has recently been
undertaken on the riparian margins of Marawhara Stream.
There are four Surveillance pest plant species present at Piha Esplanade Reserve
(agapanthus, boneseed, climbing asparagus, and montbretia), all of which are at low
densities, thus effective eradication is feasible (Figure 3, Appendix 1).
GPS co-ordinates for the following isolated infestation were recorded during the field
survey:
Pest Plant Species
boneseed
7.7
GPS Co-ordinates
NZTM E1730621 N5910121
North Piha Strand
There were six Surveillance pest plant species recorded at North Piha Strand
(agapanthus, alligator weed, boneseed, Cape ivy, German ivy, and montbretia) all of
which are at very low densities, thus effective eradication is feasible 1 (Figure 4,
Appendix 1).
The following Class (iv) plants are present in small to moderate densities and should
be controlled: gladiolus and marram. Buffalo grass is present in small to moderate
quantities but does not currently threaten indigenous systems. Gazania is abundant in
the southern part of the reserve (Plate 7) and should be controlled as part of a medium
to long-term containment program.
1
Potential upstream infestations of alligator weed should be investigated in order to prevent reinvasion
following control.
© 2012
11
Contract Report No. 3014
GPS co-ordinates for the following isolated infestation were recorded during the field
survey:
Pest Plant Species
agapanthus (two plants)
7.8
GPS Co-ordinates
NZTM E1730682E N5909561
Piha Domain
One Containment environmental pest plant (Class (ii)) (gorse) and five Surveillance
environmental pest plants (Class (iii)) were recorded within the project area:
agapanthus, Cape ivy, climbing asparagus climbing dock, and Tasmanian ngaio
(Figure 5, Appendix 1). Apart from climbing asparagus, which is abundant on the
north-east facing slopes, these species all occur in small infestations thus local
eradication is feasible.
The following Class (iv) plants are present in small numbers and should be controlled:
gladiolus, Mauritius hemp, and lupin. Marram is locally common on the northern
dune area and should be controlled, given its ability to dominate foredune
communities.
Given the size of the climbing asparagus infestation, and the potential for it to spread
into nearby natural areas, a dedicated control programme is recommended. Due to the
relatively steep gradient of the site and the subsequent risk of erosion, it is
recommended that control of climbing asparagus is staged over a period of three to
five years. Control should start from the top of the slope and work down towards the
riparian margin. As the climbing asparagus, and rank grass it is growing amongst,
dies down, it will act as an effective mulch that can be planted into the following
winter.
GPS co-ordinates for the following isolated infestation were recorded during the field
survey:
Pest Plant Species
Agapanthus
Cape ivy
7.9
GPS Co-ordinates
NZTM E1730850 N5909119
NZTM E1730850 N5909119
South Piha Road Reserve
Due to the size and management regime of this reserve, very few pest plants are
present (Figure 6, Appendix 1). Gazania, buffalo grass and lupin are present in small
quantities at the northern end of the reserve, which forms part of the larger dune
system at South Piha. Effective (local) eradication of these species from this area
should be a relatively simple task. The central part of the reserve is maintained
largely for aesthetic purposes.
© 2012
12
Contract Report No. 3014
8.
PLANTING RECOMMENDATIONS
8.1
Overview
Plant schedules have been compiled for the planting areas in five reserves based on
the Waitakere City Council Planting Guide (2004) and the Auckland Regional
Council Coastal Planting Factsheets, physical site characteristics and existing
vegetation cover. They are based on species that would occur naturally on sites with
these characteristics. Other factors considered include the selection of species that are
likely to have a relatively high growth rate and survival rate. Guidance has also been
taken from the Piha Reserves Management Plan (1999).
The focus of planting efforts at Piha should be on restoring the dunes to indigenous
habitats. This will involve the gradual phasing out of key pest plants in order to allow
indigenous species to regenerate. In most cases it is not necessary to carry out
extensive plantings as there is plenty of evidence to suggest that indigenous species
will rapidly regenerate following the removal of pest plants.
Planting
recommendations in this report therefore tend to favour planting (or ‘seeding’)
clusters of indigenous species into areas that are currently dominated by adventive
plants, particularly with regards to the mid-dune and hind-dune areas.
All plant species must be eco-sourced from the Waitakere Ecological District. It is
preferable to use seed sourced from Piha, particularly for species such as pohutukawa.
Planting should be carried out in consultation with local residents, and local
community dune restoration groups, such as Piha Coastcare, who have been
undertaking dune restoration for many years.
8.2
Spinifex and pingao
Recent restoration work carried out by volunteers such as the Piha Coast Care Group
has made a significant difference to the condition of the foredunes. Spinifex, and to a
lesser degree pingao, are flourishing in foredunes areas that are not affected by human
disturbance. Given the abundance of spinifex, it is recommended that this species is
only planted where foredunes have eroded or to replace plants that have been
damaged by trampling or rabbit browse. There is an opportunity to enhance the
foredunes with more pingao.
Planting technique, planting depth and the use of fertiliser are important factors to
consider when planting sand-binding plants. Below are the planting guidelines for
spinfex and pingao taken from an article produced by the Dune Restoration Trust of
New Zealand (2011):
Spinifex
Spinifex grown in root trainers can be planted quickly in spade holes. Deep planting
(sand level at least 10 cm above surface of potting mix) will maximise root contact
with moist sand horizons and result in greater survival and better growth, especially
under conditions of moderate sand scouring by wind. The use of plants at least 60 cm
high will allow deep burial.
© 2012
13
Contract Report No. 3014
Results from planting trials have consistently shown that applying slow-release
fertiliser at planting significantly improves early establishment and growth of spinifex
(Bergin et al. 1998). Spinifex seedlings planted with fertiliser have produced several
stolons within a year of planting. The technique involves incorporating 30 g of slowrelease NPK fertiliser to the sand around the root system as the seedling is planted.
Pingao
Large numbers of container-grown seedlings can be quickly planted on foredunes
using spades. Deep planting pingao will increase survival especially on highly
dynamic beaches where there is substantial sand movement.
Planting pits need to be sufficiently deep to allow root collars of seedlings to be
planted at least 10 cm below the sand surface. Trials have demonstrated that planting
pingao seedlings in groups of 10 to 20, with approximately 50 cm spacing between
plants, has been effective in starting the dune building process within six months.
Close spacing provides mutual shelter on exposed sites and application of fertiliser
promotes growth, and thus the trapping of sand.
Application of a slow-release NPK fertiliser (e.g. Magamp, 30 g per plant,
incorporated with the sand around each seedling) does not always increase survival
but it is known to significantly increase early growth and health. Occasionally, if
there are high rates of sand accumulation at a planting site, or the sand is enriched,
there may be no immediate benefit from fertiliser. As a general rule however, it is
advisable to apply slow-release fertiliser to all plantings.
8.1
North Piha Esplanade
Two areas have been identified that would benefit from indigenous planting (Figure 7,
Appendix 1). These are indicative only, as areas that require planting will be more
easily identified following removal of environmental pest plants.
Rather than planting large numbers of indigenous species throughout the reserve, a
more passive approach of enhancement planting should be taken. Rather than carry
out extensive pest plant control and planting, there is an opportunity to interplant
species such taupata, coastal karamu, tauhinu, karo, harakeke and coastal toetoe
(Austroderia splendens). Plants should be arranged in robust clusters of 5 to 8 plants
of mixed species, which can be scattered throughout the planting area. In the northern
part of the reserve, where the karo shrubland seems to be advancing towards the
foredunes, planting may not be necessary at all.
Planting Area 1 comprises hind and mid-dune areas dominated by rank grassland and
locally common lupin. These areas can be spot-sprayed and planted with appropriate
indigenous trees and shrubs such as and karo. These species will eventually shade out
the surrounding grass, allowing for the regeneration and spread of indigenous plants.
Planting Area 2 comprises mid-dune slacks infested with lupin and foredunes, the
latter of which are currently free from any pest plant infestations. The control of lupin
will allow indigenous plant species to regenerate in the dune slacks.
© 2012
14
Contract Report No. 3014
The foredunes of the reserve would benefit from a limited amount of pingao scattered
throughout the existing spinifex grassland.
Plant schedules are presented in Tables 1 and 2 below:
Table 1: Plant Schedule for Area 1.
Species
Common Name
Grade
Austroderia splendens
Coprosma repens
Ficinia nodosa
Ozothamnus leptophyllus
Phormium tenax
Pittosporum crassifolium
Total
coastal toetoe
taupata
knobby clubrush
tauhinu
harakeke, flax
karo
RT
PB3
RT
PB3
PB3
PB3
Spacing
(m)
1
1
1
3
1
3
Number
50
150
250
100
250
100
900
Table 2: Plant Schedule for Area 2.
Species
1
Ficinia nodosa
2
Ficinia spiralis
1
Ozothamnus leptophyllus
Total
Common Name
Grade
knobby clubrush
pingao
tauhinu
RT
RT
PB3
Spacing
(m)
1
1
3
Number
250
250
150
650
1. Plant in mid-dune areas.
2. Plant on foredunes.
8.2
Les Waygood Park
In the Piha Reserves Management Plan (1999) it states that vegetation management at
Les Waygood Park will mostly be focused on encouraging the regeneration of
indigenous vegetation. This will include control of pest plants that are a threat to the
indigenous vegetation. Supplementary planting of eco-sourced indigenous species
may occur in the area south of the car park and towards the main beach access if
regeneration is not occurring naturally. The only areas that will be actively planted
are the riparian edges of Marawhara Stream and areas where there have been dune
blowouts in order to reduce the amount of wind blown sand.
Taking the above into account, four areas have been identified that would benefit
from indigenous planting (Figure 8, Appendix 1). These areas are indicative only, as
areas that require planting will be more easily identified following removal of
environmental pest plants.
Planting Area 1 is located along the upper bank of Wekatahi Stream, where the
vegetation is dominated by a thin strip of rank kikuyu, with occasional Yorkshire fog
(Holcus lanatus), veldt grass (Ehrharta erecta), planted hebes (Hebe spp.), and
harakeke/NZ flax (Phormium tenax).
Planting Area 2 comprises a small area surrounding a toilet block in the campsite.
Tasmanian ngaio is the most common pest plant and, following its removal, should be
replaced with appropriate indigenous coastal tree and shrub species.
© 2012
15
Contract Report No. 3014
Planting Areas 3 and 4 comprise shallow dune slacks dominated by vetch and kikuyu,
with locally common Yorkshire fog and buffalo grass. Indigenous species include
locally common pohuehue and occasional karo, wiwi, and ti kouka/cabbage tree.
Rather than carry out extensive pest plant control and planting, there is an opportunity
to interplant these areas with indigenous species such as harakeke, manuka
(Leptospermum scoparium), ti kouka/cabbage tree, giant umbrella sedge (Cyperus
ustulatus), and toetoe. Plants should be arranged in robust clusters of 5-8 plants of
mixed species, which can be locally scattered throughout the planting area.
Plant schedules are presented in Tables 3 and 4 below:
Table 3: Plant Schedule for Area 1.
Species
Common Name
Austroderia fulvida
Carex virgata
Coprosma robusta
Cordyline australis
Cyperus ustulatus
Leptospermum scoparium
Melicytus ramiflorus
Phormium tenax
Total
toetoe
purei
karamu
ti kouka, cabbage tree
giant umbrella sedge
manuka
mahoe
harakeke, flax
Grade
PB3
RT
PB3
PB3
PB3
PB3
PB3
PB3
Spacing
(m)
1
0.5
1
1
1
1
1
1
Number
150
300
50
50
125
50
25
250
1,000
Table 4: Plant Schedule for Area 2.
Species
Common Name
Metrosideros excelsa
Myoporum laetum
Phormium tenax
Pittosporum crassifolium
Total
pohutukawa
ngaio
harakeke, flax
karo
Grade
PB5
PB5
PB3
PB3
Spacing
(m)
5
5
1
3
Number
3
10
30
10
53
Table 5: Plant Schedule for Area 3.
Species
Common Name
Austroderia splendens
Coprosma macrocarpa
subsp. minor
Cordyline australis
1
Cyperus ustulatus
Leptospermum scoparium
Metrosideros excelsa
Myoporum laetum
Phormium tenax
Pittosporum crassifolium
Total
toetoe
karamu
PB3
PB3
Spacing
(m)
1
1
ti kouka, cabbage tree
giant umbrella sedge
manuka
pohutukawa
ngaio
harakeke, flax
karo
PB3
PB3
PB3
PB5
PB5
PB3
PB3
1
1
1
5
3
1
3
© 2012
16
Grade
Number
200
40
40
100
125
10
15
300
20
850
Contract Report No. 3014
Table 6: Plant Schedule for Area 4.
Grade
Spacing
(m)
toetoe
karamu
PB3
PB3
1
1
35
15
ti kouka, cabbage tree
giant umbrella sedge
manuka
pohutukawa
ngaio
harakeke, flax
karo
PB3
PB3
PB3
PB5
PB5
PB3
PB3
1
1
1
5
3
1
3
20
35
50
5
5
75
10
250
Species
Common Name
Austroderia splendens
Coprosma macrocarpa
subsp. minor
Cordyline australis
1
Cyperus ustulatus
Leptospermum scoparium
Metrosideros excelsa
Myoporum laetum
Phormium tenax
Pittosporum crassifolium
Total
Number*
1. Plant in damp areas, e.g. dune hollows.
8.3
Piha Esplanade Reserve
In the Piha Reserve Management Plan 1999 it is proposed to leave the Piha Esplanade
Reserve and the Wekatahi Reserve as they are with no further active planting. Pest
plant control will be carried out on prioritised species, particularly to encourage
regeneration of indigenous riparian plants (WCC 1999).
8.4
North Piha Strand
There is potential to plant a significant proportion of the reserve, mainly within the
hind-dunes and dune slacks. Species such as karo and taupata (Coprosma repens)
have established in parts of North Piha Strand, mainly in the mid-dunes, and may well
continue to spread. Taking this into account, two small ‘trial’ areas have been
identified that would benefit from indigenous planting (Figure 9, Appendix 1). These
areas are located in dune slacks in the south of the reserve and they are relatively free
from smothering pest plants such as vetch and kikuyu, and require minimal site
preparation.
Planting Areas 1 and 2 comprise shallow dune slacks and exotic herbfields on
relatively flat, consolidated sand. Most of the plants present are low-stature species
such as gazania, veldt grass, large quaking grass (Briza maxima), catsear
(Hypochaeris radicata), gravel groundsel (Senecio skirrhodon), catchfly (Silene
gallica), and hairy birdsfoot trefoil (Lotus suaveolens). Kikuyu and vetch are largely
absent.
There is an opportunity to interplant these areas with indigenous species such as
harakeke (Phormium tenax), giant umbrella sedge (Cyperus ustulatus), and toetoe.
Plants should be arranged in robust clusters of 5-8 plants of mixed species, which can
be scattered throughout the planting areas.
© 2012
17
Contract Report No. 3014
Plant schedules are presented in Tables 7 and 8 below:
Table 7: Plant Schedule for Area 1.
Species
Common Name
Austroderia splendens
Coprosma repens
Muehlenbeckia complexa
Phormium tenax
Total
toetoe
taupata
pohuehue
harakeke, flax
Grade
PB3
PB3
PB3
PB3
Spacing
(m)
1
1
1
1
Number
100
25
25
100
250
Table 8: Plant Schedule for Area 2.
8.5
Species
Common Name
Austroderia splendens
Coprosma repens
Muehlenbeckia complexa
Phormium tenax
Total
toetoe
taupata
pohuehue
harakeke, flax
Grade
PB3
PB3
PB3
PB3
Spacing
(m)
1
1
1
1
Number
125
40
50
135
350
Piha Domain
Two planting areas have been identified in the southern part of Piha Domain
(Figure 10, Appendix 1).
Planting Area 1 comprises a small stabilised dune planted in a range of indigenous
species together with Tasmanian ngaio, which was mistakenly planted instead of the
indigenous ngaio. There is an opportunity to enhance this area with additional
plantings, with a view to filling in open areas currently characterised by inkweed
(Phytolacca octandra) and rank grass, and eventually connect this small ‘island’ of
shrubland with indigenous vegetation to the south (see below).
Area 2 comprises the steep north-facing slopes characterised by rank grass and a
significant infestation of climbing asparagus. This area buffers the lower reaches of
the Piha Stream. As stated in the Piha Reserve Management Plan 1999, the
restoration of the riparian margins of Piha Stream is seen as an important measure to
restore and enhance both the ecological values and water quality. There is an
opportunity to build on this objective by creating a coastal forest on these slopes.
Planting should be concentrated along the riparian buffer, while on the mid to upper
slopes, tree species such as pohutukawa, karaka (Corynocarpus laevigatus),
pohutukawa, and ngaio, and can be scattered, as well as planted in clusters, in order to
set the trajectory towards an indigenous coastal forest habitat. As discussed in Section
7.8, the control of climbing asparagus in Area 2 needs to be staged over a period of
three to five years in order to minimise the potential erosion risk. Planting will
therefore need to be staged accordingly over the same time period. It is recommended
that control operations, and subsequent planting, start at the top of the slope and work
downwards in stages. Climbing asparagus will continue to disperse downhill if the
bottom of the slope is controlled first, reinvading previously controlled areas.
© 2012
18
Contract Report No. 3014
Plant schedules are presented in Tables 9 and 10 below:
Table 9: Plant Schedule for Area 1.
Species
Common Name
Grade
Coprosma repens
Cordyline australis
Kunzea ericoides
1
Macropiper excelsa
Metrosideros excelsa
Myoporum laetum
Phormium tenax
Pittosporum crassifolium
Total
taupata
ti kouka, cabbage tree
kanuka
kawakawa
pohutukawa
ngaio
harakeke, flax
karo
PB3
PB3
PB3
PB3
PB8
PB3
PB3
PB3
Spacing
(m)
1
1
1
1
5
5
1
3
Number
50
50
50
50
15
15
150
50
430
1. Plant in shaded areas under the existing canopy.
Table 10: Plant Schedule for Area 2.
Species
Common Name
Grade
Coprosma robusta
Cordyline australis
1
Corynocarpus laevigatus
Leptospermum scoparium
Kunzea ericoides
Metrosideros excelsa
Myoporum laetum
Phormium tenax
1
Pouteria costata
Sophora fulvida
1
Vitex lucens
Total
karamu
ti kouka, cabbage tree
karaka
manuka
kanuka
pohutukawa
ngaio
harakeke, flax
tawapou
kowhai
puriri
PB3
PB3
PB3
PB3
PB3
PB8
PB3
PB3
PB8
PB3
PB8
Spacing
(m)
1
1
5
1
1
5
5
1
5
5
5
Number
500
500
150
600
250
200
50
500
50
100
100
3,000
1. Plant in Years 3-5 once indigenous canopy has formed.
9.
PEST ANIMAL CONTROL
9.1
Rabbits
Rabbits are a significant pest animal threat to the indigenous dune vegetation, mainly
through browsing seedlings and adolescent plants. Their control is essential for the
health of the sand-binding plant species, particularly pingao. Although occasional
droppings and digging were observed during the survey, there seemed to be little to no
browse on pingao. Local residents, however, have reported that rabbits have increased
in abundance at Piha since 2011 (M. Miller, Auckland Council, pers. comm. 2012).
Rabbit browse should be monitored on a regular basis. If required, Pindone dispensed
from bait stations can be used to suppress rabbit numbers. All bait is dyed green to
identify it as a poison and to deter birds from eating it.
© 2012
19
Contract Report No. 3014
9.2
Predators
A suite of mammalian pests is likely to frequent the dunes at Piha, including stoats
(Mustela erminea), hedgehogs (Erinaceus europaeus), rats (Rattus spp.) and feral cats
(Felis cattus).
These species are a significant threat to indigenous birds such as northern New
Zealand dotterel (Charadrius obscurus aquilonius) (Threatened-Nationally
Vulnerable), northern little blue penguin (Eudyptula minor iredalei) (At RiskDeclining), and New Zealand pipit (Anthus novaeseelandiae) (At Risk-Declining), all
of which occur at Piha. Control of stoats, hedgehogs and rats in the dunes should be
carried out on a regular basis, particularly during bird breeding and fledging seasons.
The Auckland Council Biosecurity team can assist with animal pest control.
Control of feral cats could be undertaken by trialling live traps, which allow any nontarget animal to be released unharmed. [The one drawback of live traps is that they
require checking on a daily basis, which may only be feasible if local volunteers
become involved.]
10.
MONITORING
The future management of the Piha Reserves could be assisted through the
implementation of long-term vegetation monitoring.
Establishing permanent
vegetation plots will provide data on the rates and types of succession and invasion in
duneland habitats at Piha. From this data it will be possible to determine which
indigenous species are most able to compete with pest plants; which species are the
most vulnerable to invasion by pest plants; and which areas require the most urgent
control. Establishing permanent photopoints at various locations in the park will also
provide a useful visual record of changes in vegetation patterns over time, and can be
carried out by volunteers and community groups. Continued support and advice
should be provided to community restoration groups at Piha in order to assist the
ecological restoration of the dunelands with appropriate indigenous species.
Following the control of large pest plant infestations, it will be critical to detect and
remove seedlings in order to exhaust the seed banks of pest plants (with a view to
eventual eradication), particularly for prolific seeding species such as lupin, gazania
and marram.
11.
TIMING
A four-year work plan is outlined below. Timing is based on the Auckland Council
financial year of 1 July to 30 June.
© 2012
20
Contract Report No. 3014
Year 1 (2012/2013)
Task
1. Initial pest plant control (all areas to be planted).
2. Follow up pest plant control.
3. Site preparation (blanket spray, weed-eating, etc).
4. Monitor for rabbit sign; implement control as
required in consultation with local residents and
Auckland Council Biosecurity.
5. Planting.
Timing
September 2012-December 2012
March-April 2013
March-April 2013
March-April 2013
May-June 2013
Year 2 (2013/2014)
Task
1. Blanking (as required).
2. Monitor for rabbit sign; implement control as
required in consultation with local residents and
Auckland Council Biosecurity.
3. Implement predator control. Service traps on a
fortnightly basis or as recommended by Auckland
Council Biosecurity.
4. Ongoing follow up pest plant control and
monitoring.
5. Site preparation (if staged planting).
6. Planting (if staged planting).
Timing
July-August 2013
August 2013
August 2013-February 2014
January-April 2014
March-April 2014
May-June 2014
Year 3 (2014/2015)
Task
1. Infill planting (as required).
2. Monitor for rabbit sign; implement control as
required in consultation with local residents and
Auckland Council Biosecurity.
3. Implement predator control. Service traps on a
fortnightly basis or as recommended by Auckland
Council Biosecurity
4. Ongoing follow up pest plant control and
monitoring.
Timing
July-August 2014
May-August 2014
August 2014-February 2015
January-April 2015
Year 4 (2015/2016 onwards)
Task
1. Ongoing follow up plant pest control and
monitoring.
2. Monitor for rabbit sign; implement control as
required in consultation with local residents and
Auckland Council Biosecurity.
3. Implement predator control. Service traps on a
fortnightly basis or as recommended by Auckland
Council Biosecurity.
© 2012
21
Timing
January-April 2016
May-August 2015
August 2015-February 2016
Contract Report No. 3014
REFERENCES
Agrichemical Users’ Code of Practice: NZ Agrichemical Education Trust.
Auckland Regional Council. 2007: Regional Pest Management Strategy 2007-2012.
Auckland Regional Council (no date): Coastal Planting Guide 2: Dunes.
http://www.arc.govt.nz/albany/fms/main/Documents/Environment/Plants%20and%20
animals/coastal%20planting%20guide%202.pdf
Bergin D.O., Kimberley M.O., and Ede F.J. 1998: Revegetation of Sand Dunes Using
Spinifex (Spinifex sericeus) in New Zealand. Proceedings of New South Wales
Coastal Conference, November 1998, Batemans Bay, NSW, Australia. 6 pp.
Denyer K., Cutting M., Campbell G., Green C., and Hilton M. 1993: Waitakere Ecological
District. Survey Report for the Protected Natural Areas Programme. Auckland
Regional Council, Auckland.
Dune Restoration Trust of NZ 2011: Technical Handbook Section 7.2: Native Vegetation on
Foredunes. Spinifex - Guidelines for seed collection, propagation and establishment.
ISSN 2230-6919.
Dune Restoration Trust of NZ 2011: Technical Handbook Section 7.4: Native Vegetation on
Foredunes. Pingao - Guidelines for seed collection, propagation and establishment.
ISSN 2230-6919.
Hilton M. 2006: The loss of New Zealand’s active dunes and the spread of marram grass
(Ammophila arenaria). New Zealand Geographer 62: 105-120.
Lindsay H., Wild C., and Byers S. 2009: Auckland Protection Strategy. A report to the
Nature Heritage Fund Committee. Nature Heritage Fund, Wellington.
Ministry for the Environment and Department of Conservation 2007a: Protecting our Places.
Introducing the national priorities for protecting rare and threatened native
biodiversity on private land. Ministry for the Environment and Department of
Conservation, Wellington. 7 page brochure.
New Zealand Standard NZS 8409 2004: The Management of Agrichemicals.
Waitakere City Council 1999: Piha Reserves Management Plan Final Management Plan,
September 1999.
Waitakere City Council 2010: Native to the West. A guide for planting and restoring the
nature of Waitakere City.
Wildland Consultants Ltd 2008: Ecological Assessment and Monitoring for a Wastewater
Land Disposal Field, Les Waygood Park, Piha. Wildlands Consultants Contract
Report No.2081.
© 2012
22
Contract Report No. 3014
Wildland Consultants Ltd 2011a: Environmental Pest Plant Management and Planting Plan
for Les Waygood Park, Piha. Wildland Consultants Ltd Contract Report No. 2819.
12 pp plus appendices.
Wildland Consultants Ltd 2011b: Environmental Pest Plant Management and Planting Plan
for North Piha Strand, Piha. Wildland Consultants Ltd Contract Report No. 2838.
11 pp plus appendices.
© 2012
23
Contract Report No. 3014
APPENDIX 1
FIGURES
© 2012
24
Contract Report No. 3014
© 2012
25
Contract Report No. 3014
© 2012
26
Contract Report No. 3014
© 2012
27
Contract Report No. 3014
© 2012
28
Contract Report No. 3014
© 2012
29
Contract Report No. 3014
© 2012
30
Contract Report No. 3014
© 2012
31
Contract Report No. 3014
© 2012
32
Contract Report No. 3014
© 2012
33
Contract Report No. 3014
© 2012
34
Contract Report No. 3014
APPENDIX 2
SITE PHOTOGRAPHS
© 2012
35
Contract Report No. 3014
Plate 1: View looking north-east across the middle area of North Piha Esplanade, with the
bottom of Monkey Rock (Takutapu) visible in the right-hand side of the photo. The foredunes
dominated by spinifex (Spinifex sericeus) contrast with the dense infestation of lupin
(Lupinus arboreus) and exotic grassland in the dune slacks. In the background, the dunes
are characterised by a steadily advancing area of karo (Pittosporum crassifolium) forest.
18 September 2012.
Plate 2: View looking south along the spinifex-dominant foredunes at North Piha Esplanade.
The exposed, dynamic nature of these dunes helps resist the invasion of most pest plant
species, although marram has the potential to cause significant damage.
18 September 2012.
© 2012
36
Contract Report No. 3014
Plate 3: View looking north along the foredunes and dune slack at Les Waygood Park
(Weed Infestation Area 1). Lupin is often the dominant pest plant in the dune slacks and middunes, where it adversely affects a range of indigenous plants. 22 November 2011.
Plate 4: View looking south towards Lion Rock along the mid-dunes of North Piha
Strand (Weed Infestation Area 3). The mid-dunes and dune slacks in this reserve are
highly modified, and are characterised by rank exotic grasses, vetch, lupin and
occasional pohuehue. 22 November 2011.
© 2012
37
Contract Report No. 3014
Plate 5: View looking south-east across a large hillslope buffering the Piha Stream
in the southern part of Piha Domain (Weed Infestation Area 4). The area is
characterised by a dense layer of climbing asparagus (Asparagus scandens)
over rank exotic grassland, with scattered infestations of lupin, gorse (Ulex
europeaus) and agapanthus (Agapanthus praecox). 18 September 2012.
Plate 6: A large infestation of Cape ivy (Senecio angulatus) grows amongst
pohuehue (Muehlenbeckia complexa) and scattered agapanthus in Weed Infestation
Area 3, Piha Domain. 18 September 2012.
© 2012
38
Contract Report No. 3014
Plate 7: Gazania is abundant in the shallow dune slacks of Weed Infestation Area 4,
North Piha Strand. Areas such as this are good candidates for indigenous planting
given the scarcity of smothering pest plant species such as kikuyu (Cenchrus
clandestinus) and vetch (Vicia sativa). 22 November 2011.
© 2012
39
Contract Report No. 3014
APPENDIX 3
LIST OF ENVIRONMENTAL PEST PLANT SPECIES
RECORDED FROM THE PROJECT AREA
Common Name
agapanthus
alligator weed
boneseed
buffalo grass*
Cape ivy
climbing asparagus
climbing dock
fruit salad plant*
garden nasturtium*
gazania*
German ivy
gorse
gladiolius*
Indian doab*
kikuyu*
lupin*
marram grass*
montbretia
radiata pine*
Tasmanian ngaio
tree aloe*
umbrella sedge*
veldt grass*
vetch*
Scientific Name
Agapanthus praecox
Alternanthera philoxeroides
Chrysanthemoides monilifera
Stenotaphrum secundatum
Senecio angulatus
Asparagus scandens
Rumex sagittatus
Monstera deliciosa
Tropaeolum majus
Gazania linearis
Delairea odorata
Ulex europaeus
Gladiolus undulatus
Cynodon dactylon
Cenchrus clandestinus
Lupin arboreus
Ammophila arenaria
Crocosmia ×crocosmiiflora
Pinus radiata
Myoporum insulare
Aloe arboreus
Cyperus eragrostis
Ehrharta erecta
Vicia sativa
* Not currently included in the ARPMS.
© 2012
40
Contract Report No. 3014
APPENDIX 4
LIST OF VASCULAR PLANT SPECIES FOR PIHA
RESERVES, 2011-2012
INDIGENOUS SPECIES
Monocot. trees and shrubs
tī kōuka, cabbage tree
nīkau
Cordyline australis
Rhopalostylis sapida
Dicot. trees and shrubs
Coprosma repens
Coprosma robusta
Coprosma macrocarpa subsp. minor × C. robusta
Geniostoma ligustrifolium var. ligustrifolium
Griselinia lucida (planted)
Leucopogon fasciculatus
Macropiper excelsum subsp. excelsum
Melicope ternate (planted)
Melicytus ramiflorus subsp. ramiflorus
Metrosideros excelsa
Myoporum laetum
Myrsine australis
Olearia solandri
Ozothamnus leptophyllus
Pittosporum crassifolium
Pseudopanax crassifolius × P. lessonii
Pseudopanax lessonii
Sophora chathamica
taupata
karamū, kāramuramu
hangehange
puka
mingimingi
kawakawa
wharangi
māhoe
pōhutukawa
ngaio
māpou, matipou, māpau
coastal tree daisy
tauhinu
karo
houpara
kōwhai
Dicot. lianes
Calystegia soldanella
Muehlenbeckia complexa
panahi, shore bindweed
pōhuehue
Ferns
Asplenium bulbiferum
Asplenium polyodon
Blechnum filiforme
Cyathea dealbata
Microsorum pustulatum
mouku, hen and chicken fern
petako
pānako
ponga, silver fern
kōwaowao, pāraharaha, hound’s tongue
fern
rārahu, bracken
Pteridium esculentum
© 2012
41
Contract Report No. 3014
Grasses
Austroderia fulvida
Austroderia splendens
Oplismenus hirtellus subsp. imbecillis
Spinifex sericeus
toetoe
toetoe
kōwhangatara, spinifex
Sedges
pūrua grass
Bolboschoenus sp.
Carex aff. raoulii ("raotest")
Carex pumila
Cyperus ustulatus f. ustulatus
Ficinia nodosa
Ficinia spiralis
Isolepis cernua
Machaerina juncea
toetoe upoko-tangata
wīwī
pīngao
Rushes
Apodasmia similis
oioi
Monocot. herbs (other than orchids, grasses, sedges, and rushes)
Phormium tenax
Typha orientalis
harakeke, flax
raupō
Dicot. herbs (other than composites)
Apium prostratum subsp. prostratum var. filiforme
Haloragis erecta subsp. erecta
Hydrocotyle novae-zeelandiae var. novae-zeelandiae
Oxalis exilis
Oxalis magellanica
Solanum nodiflorum
Tetragonia implexicoma
tūtae-kōau, New Zealand celery
toatoa
tūtae-kāhu
raupeti
kōkihi, rengamutu
NATURALISED AND EXOTIC SPECIES
Gymnosperms
Pinus radiata
radiata pine
Dicot. trees and shrubs
Callistemon sp.
Chrysanthemoides monilifera
Lupinus arboreus
Myoporum insulare (planted)
© 2012
bottlebrush
boneseed
lupin
Australian ngaio
42
Contract Report No. 3014
Pelargonium sp.
Senecio angulatus
Ulex europaeus
geranium
Cape ivy
gorse
Monocot. lianes
Asparagus scandens
Monstera deliciosa
climbing asparagus
fruit salad plant
Dicot. lianes
Delairea odorata
Rumex sagittatus
German ivy
climbing dock
Grasses
Ammophila arenaria
Briza maxima
Bromus diandrus
Bromus willdenowii
Cenchrus clandestinus
Cynodon dactylon
Dactylis glomerata
Ehrharta erecta
Holcus lanatus
Lagurus ovatus
Paspalum distichum
Schedonorus arundinaceus
Sporobolus africanus
Stenotaphrum secundatum
marram
large quaking grass
ripgut brome
prairie grass
kikuyu grass
Indian doab
cocksfoot
veldt grass
Yorkshire fog
harestail
Mercer grass
tall fescue
ratstail
buffalo grass
Sedges
Cyperus eragrostis
umbrella sedge
Monocot. herbs (other than orchids, grasses, sedges, and rushes)
Agapanthus praecox
Allium triquetrum
Aloe arborescens
Crocosmia ×crocosmiiflora
Freesia refracta
Gladiolus undulatus
agapanthus
onion weed
aloe
montbretia
freesia
gladiolus
Composite herbs
Arctotheca calendula
Cirsium vulgare
Conyza sumatrensis
Crepis capillaris
cape weed
Scotch thistle
broad-leaved fleabane
hawksbeard
© 2012
43
Contract Report No. 3014
Gazania linearis
Helminthotheca echioides
Hypochaeris radicata
Osteospermum fruticosum
Senecio skirrhodon
Sonchus oleraceus
gazania
oxtongue
catsear
rain daisy, dimorphotheca
gravel groundsel
puha, sow thistle
Dicot. herbs (other than composites)
Alternanthera philoxeroides
Anagallis arvensis
Cerastium fontanum subsp. vulgare
Euphorbia helioscopia
Geranium robertianum
Lotus pedunculatus
Lotus suaveolens
Myosotis sylvatica
Orobanche minor
Oxalis incarnata
Plantago lanceolata
Plantago major
Rumex conglomeratus
Sagina procumbens
Tropaeolum majus
Veronica persica
Vicia sativa
© 2012
alligator weed
scarlet pimpernel
mouse-ear chickweed
sun spurge
herb Robert
lotus
hairy birdsfoot trefoil
garden forget-me-not
broomrape
lilac oxalis
narrow-leaved plantain
broad-leaved plantain
clustered dock
pearlwort
garden nasturtium
scrambling speedwell
vetch
44
Contract Report No. 3014
APPENDIX 5
RECOMMENDED HERBICIDE TREATMENTS
Pest Plant
Control Method(s)
Chemical(s)
Application Rate
Timing
Remarks
Agapanthus
(Agapanthus praecox)
Dig out and dispose off site
-
-
Year round
Only if this can be done without
posing a weed hygiene risk
Knapsack - foliar spray
Knapsack - foliar spray
Knapsack - foliar spray
(terrestrial sites only)
Knapsack - foliar spray
(aquatic sites)
Hand pull seedlings/small
plants
Cut and treat stump
Knapsack - foliar spray
Triclopyr
Metsulfuron
Metsulfuron
60ml/10 litres water
2.5g/10 litres water
5g/10 litres water plus 10ml
surfactant
200ml/10 litres water
Year round
Year round
October-March
Alligator weed
(Alternanthera
philoxeroides)
Boneseed
(Chrysanthemoides
monilifera)
Glyphosate
October-March
Year round
Metsulfuron
Glyphosate
1g/1 litre water
100ml/10 litres water plus
20ml surfactant
Year round
October-March best
results
Buffalo grass
(Stenotaphrum
secundatum)
Knapsack - foliar spray
Glyphosate
150ml/10 litres water
Knapsack - foliar spray
Haloxyfop
60ml/10 litres water plus 50ml Year round
crop oil
Cape ivy
(Senecio angulatus)
Climbing asparagus
(Asparagus scandens)
Climbing dock
(Rumex sagittatus)
Fruit salad plant
(Monstera deliciosa)
Cut and treat stump
Knapsack - foliar spray
Knapsack - foliar spray
Triclopyr
Metsulfuron
Glyphosate
60ml/1 litre water
5g/10 litres water
100ml/10 litres water
October-March
October-March
October-March
Knapsack - foliar spray
Metsulfuron
5g/10 litres water
November-February
Garden nasturtium
(Tropaeolum majus)
Gazania
(Gazania linearis)
Year round
Hand pull seedlings/small
plants
Cut and treat stump
Knapsack - foliar spray
Triclopyr
Metsulfuron
60ml/1 litre water
5g/10 litres water
October-March
November-March
Dig out
Knapsack - foliar spray
Clopyralid
40ml/10 litres plus 20ml
surfactant
Year round
October-March best
results
© 2012
Take extreme care around
waterways.
Use glyphosate formulation
approved for use over water.
Thoroughly cover all foliage.
Thoroughly cover all foliage. Can
be used around revegetation
plantings of non-grass species
without any overspray damage.
Year round
45
Contract Report No. 3014
Pull vines away from non-target
vegetation before spraying.
Pest Plant
Control Method(s)
Chemical(s)
Application Rate
Timing
German ivy
(Delairea odorata)
Gladiolus
(Gladiolus undulatus)
Knapsack - foliar spray
Metsulfuron
5g/10 litres water
October-March
Knapsack - foliar spray
Glyphosate
October
Knapsack - foliar spray
Metsulfuron
Knapsack - foliar spray
Metsulfuron
Cut and treat stumps
Knapsack - foliar spray
Triclopyr
Glyphosate
100ml/10 litres water plus
20ml surfactant
5g/10 litres water plus 10ml
surfactant
5g/10 litres water plus 10ml
Pulse
60ml/1 litre water
100ml/10 litres water
Knapsack - foliar spray
Haloxyfop
60ml/10 litres water
Year round
Kikuyu grass
(Cenchrus clandestinus)
Knapsack - foliar spray
Knapsack - foliar spray
Glyphosate
Haloxyfop
100ml/10 litres water
60ml/10 litres water
Year round
Year round
Lupin
(Lupinus arboreus)
Marram grass
(Ammophila arenaria)
Cut and treat stumps
Metsulfuron
5g/1 litre water, plus 2 ml
surfactant
Year round
Gorse
(Ulex europaeus)
Indian doab
(Cynodon dactylon)
Montbretia
(Crocosmia
×crocosmiiflora)
Radiata pine
(Pinus radiata)
Tasmanian ngaio
(Myoporum insulare)
Dig out small infestations and
dispose of rhizomes
Knapsack - foliar spray
Glyphosate
Knapsack - foliar spray
Haloxyfop
Knapsack - foliar spray
Metsulfuron
October
November-March
October-March
Year round
Year round
Thoroughly cover all foliage.
Year round
5g/10 litres water + 20ml
surfactant
October-February
Thoroughly cover all foliage. Can
be used around revegetation
plantings of non-grass species
without any overspray damage.
Follow-up control will be necessary.
Hand pull seedlings/small
plants
Cut and treat stumps
Drill and inject, frill and spray
Year round
46
Thoroughly cover all foliage. Can
be used around revegetation
plantings of non-grass species
without any overspray damage.
Thoroughly cover all foliage.
Thoroughly cover all foliage. Can
be used around revegetation
plantings of non-grass species
without any overspray damage.
125ml/10 litres water plus
20ml surfactant
150ml/10 litres water plus
100ml crop oil
Year round
© 2012
Thoroughly cover all foliage
Year round
Ring bark or fell larger trees
Triclopyr
Metsulfuron
Remarks
60ml/1 litre water
5g/1 litre water, plus 2 ml
surfactant
Contract Report No. 3014
October-April
October-April
Pest Plant
Control Method(s)
Chemical(s)
Application Rate
Timing
Tree aloe
(Aloe arboreus)
Umbrella sedge
(Cyperus ustulatus)
Veldt grass
(Ehrharta erecta)
Vetch
(Vicia sativa)
Knapsack - foliar spray
Metsulfuron
October-March
Knapsack - foliar spray
Metsulfuron
5g/10 litre water plus 20ml
surfactant
5g/10 litres water
Knapsack - foliar spray
Glyphosate
100ml/10 litres water
October-March
Knapsack - foliar spray
Glyphosate
100ml/10 litres water
October-March
© 2012
47
Contract Report No. 3014
November-March
Remarks
AUCKLAND OFFICE: 97A MT EDEN ROAD, MT EDEN, AUCKLAND 1023
P.O. BOX 46 299, HERNE BAY, AUCKLAND 1001, Ph 09-377-4886; Fax 09-377-4889