KEY POINTS:
When Phil Brown returned to New Zealand after living in Japan he found the country so green that it "hurt my eyes".
But the damage was obviously not too serious, as the Department of Conservation manager's hawk-like vision spots the tiniest orchids and carnivorous plants in protected bush
which borders the Okura and Weiti Rivers north of Auckland.
Mr Brown, programme manager biodiversity in DoC's Auckland conservancy, is taking the Herald for a bushwalk in the Okura estuary scenic reserve to highlight Conservation Week, which started yesterday.
The Auckland region contains many DoC walkways, taking hikers anywhere from waterfalls to the top of mountains such as Mt Tamahunga at Matakana. In the Okura walkway visitors meander through regenerated kauri forest and, while not always obvious, they pass old Maori occupation sites, including middens, a pa site and food cultivation terraces.
The walkway is also part of Te Araroa (the long pathway), which will eventually run the length of the country. The 8km track starts from either Haighs Access Rd, the southern end, or Stillwater, which has more parking, and takes about three hours to walk one way.
Alternatively you can just walk as far as Dacre Cottage at the northern end of Karepiro Bay, and return to your starting point.
From Haighs Rd walkers quickly come upon a wooden footbridge which takes them across an estuary to a bank of kowhai trees and into a lush grove of nikau palms.
Startlingly thick ropes of native passion fruit vine hang over the path, lending a tropical jungle feel to the bush, which also hosts grand puriri and taraire trees.
"This is prime northern New Zealand coastal lowland forest. It is pretty uncommon now with coastal development," says Mr Brown.
He points out the puriri moth holes in the trees where caterpillars live behind a thin membrane which will eventually be nibbled through by the moths. As we climb up towards the top of a ridge a lovely scent hangs in the air, probably that of the hangehange or toropapa plants.
Mr Brown points out the regenerating kauri trees which are slowly pushing through the canopy.
Sadly he also notes some evidence of the kauri fungus which is spreading through Auckland's kauri forests.
Walkers are encouraged not to touch the kauri trunks for risk of spreading the disease.
Along the ridge tall kanuka trees creak in the wind, and in themselves are evidence of historic burn-offs. The kanuka eventually fall over and make way for the next stage of forest. Tanekaha and mapou trees also flourish along the ridgeline.
Coming down the ridge Mr Brown points out how a totara is showing evidence of some possum activity, its fibrous trunks clawed from where the pests have scaled the tree.
"We call them possum highways."
He also spots tiny orchids on the side of the path, the plants liking the light allowed by the side cuttings.
Flowering at present is the hooded green orchid, which "swallows" then releases nectar-feeding insects as a pollination device. He also sees tiny sundews, carnivorous plants with sticky hairs which trap and digest midges.
Next we discover a large collapsed puriri tree, its branches growing vertically out of the decomposing trunk to eventually form new trees.
"Puriri are possibly immortal," says Mr Brown, sounding impressed.
Bringing more life to the bush are tui and kereru, or wood pigeons, which whoosh past above. Grey warblers, fantails and kingfishers can also be found. Down on the coast, along part of the Long Bay marine reserve, you might see stilts, oystercatchers and dotterels.
Karepiro Bay features the restored brick Dacre cottage, built in the 1850s by Henry Dacre, the son of the retired sea captain Ranulf Dacre, who bought the Weiti block in 1848.
If carrying on to Stillwater follow the coastline at low tide which exposes the vast mudflats and interesting wave-cut platforms.
Or there is the overland track climbing steeply above with good views of the Whangaparaoa peninsula and the Hauraki Gulf, before dropping back to the Weiti River estuary.
From there the track follows the river, crossing private land to the Stillwater carpark.
* More information about Conservation Week can be found here
* Track information can be found here
