ONEPOTO DOMAIN: WETLAND & SANCTUARY
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Plant Stratification Zoning Plan
PLANTING PLAN Zoning & Stratification
The two key objectives in determining plant species and positioning are the maximum filtration of stormwater flowing through the site, and the provision of a rich and varied habitat for native wildlife. Planting zones have been created based on typical patterns of wetland ecological niches. Diversity of habitat has been enhanced by varying the intersection of zones, while maintaining appropriate planting gradients and buffers for each ecological zone. The positioning of planting zones varies depending on the relative proximity to the average water level. Species more suited to an aqueous environment or highly saturated soils are planted lower in the water table, while those plants less tolerant of waterlogging are planted in drier positions.
1. Wetland Zone: Aquatic -1.5m to -1.1m below water level Vegetative zone largely submerged
A meadow area has been established to further the site’s habitat diversity, providing a seasonal nesting site and a food bank of insects for resident birdlife, as well as adding to informal recreation space.
2. Wetland Zone: Emergent -1.1m to -0.3m below water level Shallow pond slope with vegetation protruding 3. Wetland Zone: Saturated -0.3m to 0.0m below water level Soils are saturated almost year-round 4. Wetland Zone: Moist 0.0m to 0.3m above water level Flooded in winter and periods of high rainfall 5. Wetland Zone: Mesic 0.3m to 5.0m above water level Occasionally flooded, but generally dry 6. Existing Dry Forest 5.0m to 25.0m above water level Free-draining upland slopes
Onepoto Domain: Wetland & Sanctuary - Group_ONE
7. Open Grassland 0.3m to 0.8m above water level Mixed native/naturalised grassland meadow
Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
The Aquatic Zone of the wetland is central to the successful passing of water through the site. It is the course of minimum interference, and is the deepest zone of the wetland, its floor being between 1.1 and 1.5m below the water surface. During excess water influx, this area of minimum obstruction allows water to pass through the site without encouraging water to back up and leading to subsequent flooding elsewhere upstream or over the wetland banks. This permanent section of open water area is important also to the the take-off and landing of birds requiring a longer run, such as pukeko and ducks. Vegetation in this area is largely submerged. Some leaves are floating, but the majority of plant life is submerged apart from flowering parts. These plants contribute to water clarifty by reducing the movement of sediment through the site. The plants in the Aquatic Zone are not likely to survive in instances where unusual drought periods leave the wetland dry even for short periods.
1. Aquatic Zone
Due to the distinct flora of this habitat, it is a rich source of fish, insects, and other aquatic invertebrate as food for birds of the wetland.
2. Emergent Zone
Plants in this zone are planted as plugs, sourced in biodegradable pots that break down over time after planting as the plants establish.
3. Saturated Zone 4. Moist Zone
5. Mesic Zone 6. Existing Dry Forest
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Chara globularis Myrophyllum propinquum Nitella hookerii Nitella pseudoflabellata Potamogeton cheesemanii Potamogeton ochreatus Ruppia polycarpa
7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
The mix of plants contributing to the Emergent Zone are solely sedge- and rush-like species, of which their growth crown is submerged and the majority of leaves reach partially or entirely above water level. The zone’s floor varies between 0.3m and 1.1m below water level, often sloping as it meets its shallower perimeter. This area contains standing water at all times other than in exceptional dry periods. There is high contact between water and vegetation herein, and subsequently maximum biofiltration of the water because of the significant microbial interaction. The emerging stems and leaves form a bridge for insects and small birds to connect to the water. As such, the zone presents an important field for foraging of water insects by birds.
1. Aquatic Zone
2. Emergent Zone
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Baumea articulata Bolboschoenus fluviatilis Elaeocharis sphacelata Schoenoplectus tabernaemontani
3. Saturated Zone 4. Moist Zone 5. Mesic Zone 6. Existing Dry Forest 7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
The Saturated Zone presents the most abundant wildlife density due to its warmer and shallower waters, as well as the shade created by the larger plant species such as harakeke. Fish and insect breeding is prolific here, as with the nesting and foraging of wading birds. Water is generally 0.0m to 0.3m deep in this zone, often sitting as a gently sloping shelf. Soils are saturated year-round, though the margins may dry out during summer periods.
1. Aquatic Zone 2. Emergent Zone
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Apodasmia similis Baumea arthrophylla Baumea rubiginosa Bolboschoenus fluviatilis Carex secta Carex virgata Cyperus ustulatus Eleocharis acuta Isolepis prolifer Phormium tenax Schoenoplectus pungens
3. Saturated Zone 4. Moist Zone 5. Mesic Zone 6. Existing Dry Forest 7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
The Moist Zone sees the emergence of ferns and dicotyledenous plants, and subsequently a greater amount of shade. There is enough oxygen in the soil to support woody plant species here, and as such species such as cabbage tree and kahikatea establish freely. These branching plants also present opportunities for birds that prefer the shelter of higher nesting sites, such as the fantail. Often puggy underfoot, the soil will usually be flooded on a seasonal basis, as well as after heavy rains. Soils sit 0.0m to 0.3m above water level.
1. Aquatic Zone 2. Emergent Zone 3. Saturated Zone
4. Moist Zone
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Carex geminata Carex lessoniana Coprosma propinqua Coprosma tenuicaulis Cordyline australis Cortaderia fulvida Dacrycarpus dacrydioides Dicksonia squarrosa Cyperus ustulatus Gahnia xanthocarpa Juncus pallidus Juncus sarophorus Laurelia novae-zelandiae Leptospermum scoparium Phormium tenax Syzygium maire
5. Mesic Zone 6. Existing Dry Forest 7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
An outer “wall� to the wetland is created by the trees in the Mesic Zone. The enclosure assists in bringing a security to birdlife of the area, as well as shade, and perching and nesting sites. Softleaved broadleaf plants and their high rate of evapotranspiration create much absorption from the wetland. This area experiences flooding occasionally, but for only very short periods. It is generally dry, sitting 0.3m to 5.0m above water level. This zone is more typical of lowland Auckland forests, where moisture is in abundance and the site is sheltered from exposure.
1. Aquatic Zone 2. Emergent Zone 3. Saturated Zone 4. Moist Zone
5. Mesic Zone
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Alectryon excelsus Carex dipsacea Carex flagellifera Carpodetus serratus Coprosma robusta Cordyline autralis Dacrycarpus dacrydioides Hebe stricta v. stricta Kunzea ericoides Leptospermum scoparium Macropiper excelsum Melicytus ramiflorus Pittosporum tenuifolium Podocarpus totara Prumnopitys taxifolia Schefflera digitata Sophora chathamica Vitex lucens
6. Existing Dry Forest 7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
The Existing Forest is only “dry” in the sense that it is neither part of the wetland nor subject to flooding, particularly given its steeper slopes ranging from 5.0m to 25m above water level. It is freedraining, and forms a band of buffer between the wetland and the residential area surrounding Onepoto Domain. This buffer shelters the site from high winds, as well as reducing human impact on the natural processes of the wetland. This existing bank of mixed native and garden-escape species provides an area of elevated nesting for insects, amphibians and birdlife familiar with a forest habitat. While distinct from this wetland restoration proposal, the surrounding band of established vegetation is also important to the health of the wetland due to its harbouring of pest weed and animal species that will affect the wetland’s prosperity. Significant species such as Tradescantia, Wild Ginger and Monkey Apple are in abundance, displacing weaker native flora. The resurrection of this zone is an important longer-term step in the wetland’s management and success.
1. Aquatic Zone 2. Emergent Zone 3. Saturated Zone 4. Moist Zone 5. Mesic Zone
6. Existing Dry Forest 7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN Zoning Development
The area designated as Open Grassland creates a transition between the manicured sportsfields and the naturalised wilds of the developed wetland. The mix of native and naturalised grasses brings together recreation and biodiversity - a rare recreation meadow opportunity in an urban realm. Ground level runs from 0.3m to 0.8m above water level. This recreation area is buffered from the deeper wetland by the higher planting of the Moist Zone, minimising noise disturbance to the wetland’s birdlife. The array of wild grasses and weeds left to flower attract an abundance of insect life - an important food bank for resident birds. This area will be closed off seasonally for the period when birds proximal to the wetland areas are nesting.
1. Aquatic Zone 2. Emergent Zone
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Anemanthele lessoniana Apodasmia similis Microlaena stipoides Naturalised exotic spp.
3. Saturated Zone 4. Moist Zone 5. Mesic Zone 6. Existing Dry Forest
7. Open Grassland 0m Onepoto Domain: Wetland & Sanctuary - Group_ONE
25m
50m
100m
200m Reuben McPeak
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Urban Ecology 2014
PLANTING PLAN
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Biodiversity Enhancing Plants
Alectryon excelsus Titoki Carpodetus serratus Putaputaweta Coprosma propinqua Mingimingi Coprosma robusta Karamu Coprosma tenuicaulis
Hukihuki / Swamp Coprosma
Cordyline australis
Ti Kouka / Cabbage Tree
Dacrycarpus dacrydioides
Kahikatea
Hebe stricta v. stricta Koromiko Juncus pallidus Wiiwii Kunzea ericoides Kanuka Leptospermum scoparium
Manuka
Macropiper excelsum Kawakawa Melicytis ramiflorus
Mahoe / Whiteywood
Phormium tenax
Harakeke / NZ Flax
Pittosporum tenuifolium
Kohuhu
Podocarpus totara Totara Prumnopitys taxifolia Matai Schefflera digitata
Pate / Seven-finger
Sophora chathamica
Coastal Kowhai
Syzygium maire
Maire Tawake / Swamp Maire
Vitex lucens Puriri Fruit production Onepoto Domain: Wetland & Sanctuary - Group_ONE
Nectar production Reuben McPeak
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Urban Ecology 2014