Why do it? Biodiversity in Gisborne

There is a very great environmental need for such a project in the Tai Rawhiti region. In a recent study of 179 countries, New Zealand had the highest proportion of native species at risk.  As Sir Paul Callaghan has pointed out, our forests are falling silent and many indigenous species are dying, and the East Coast is at the far end of the scale.

In many parts of the Gisborne district, pastoral farming, horticulture and forestry have led to an almost complete loss of indigenous vegetation. There is little riparian bush left near the coast, with the Longbush Ecosanctuary a rare exception.

Local populations of indigenous birds have sharply declined. As the Gisborne District Plan remarks, ‘Surviving bird species are generally shore birds or birds of wetland-estuary-scrub margin habitat, although some more adaptable species like tui are still relatively abundant. Weka habitat is particularly scarce and following Cyclone Bola, weka survival has not been certain.’

Of those remnants of lowland bush in the district that are protected from livestock, almost none are subject to the intensive pest and weed control that allows the full range of indigenous species of plants and animals to thrive. The District Plan also describes erosion in the Gisborne District as being among the worst in the world. The Longbush Ecosanctuary is classified as 7e4, a land type highly prone to erosion.

Fortunately there are a number of ecological restoration projects in Gisborne, including Young Nick’s Head, Tuaheni Point, Kaiti Hill and Te Wherowhero Lagoon.

Stage one - Longbush Reserve

In 2001 the project begain when Longbush Reserve, the riverside bush, was fenced and placed under a QEII covenant.

The following year, Steve Sawyer of Ecoworks began an intensive programme of weed control and trapping opossums, rats, stoats, weasels and wild cats.

The owners worked with Andy Carrie from the Conservation Corps at Tai Rawhiti Polytechnic to plant the clearings.

The restoration of the bush along the Waimata River is now complete (although ongoing maintenance is essential). The results to date have been dramatic.

The forest floor has been colonised by kawakawa and other plants, and rare plants including black and hooded green orchids are re-emerging (See list of plants at Longbush, attached).

The numbers of indigenous birds including kereru, tui, bell-bird, fantail, kingfisher and ruru (native owls) have markedly increased, with sightings of rare species including whiteheads, weka and the New Zealand falcon.

Grey geckos, long-tailed bats and black-headed tree weta live in the bush, and weta from the Longbush Ecosanctuary have been used as a source population for a tuatara and petrel re-introduction project at Young Nick’s Head in Gisborne.

The Longbush Ecosanctuary is now the only area in the Turanga Ecological District with such high remaining levels of biodiversity. Almost every other remnant forest area has high pest densities and abundant exotic weeds.

Stage two - the wildlife corridors

The second stage in the restoration of the Longbush Ecosanctuary was to create wildlife corridors between the Reserve and regenerating bush in the valleys, which are themselves adjacent to large QEII covenanted areas on several other properties across the western ridge.

This began in 2000 with a planting by members of the Thorpe family, followed by plantings by the Conservation Corps at Tai Rawhiti Polytechnic from 2001-6. In 2006 the Biodiversity Fund awarded a grant to support this stage in the programme, followed by a three year grant over 2007-9.

Since 2000, wildlife corridors have been created along the three streams which run down the valleys from the high western ridges, across the flats and down to the Waimata River. The most southerly of these corridors has been achieved by natural regeneration, while those along the middle and most northerly streams are created by fencing and planting.

Groves of berry-bearing trees (titoki, karaka, puriri and taraire) and the Rene Orchiston collection of 60 varieties of harakeke (New Zealand flax) have been planted along the foothills to provide seasonal food supplies for native birds. A group of local weavers led by Meikle McNab of Ngati Porou care for the Orchiston collection, which is regarded as a national taonga or treasure.

Stage three - The Longbush Ecosanctuary

In 2010 the third stage of the restoration of the Longbush Ecosanctuary got underway. The sheep that grazed the hills were removed, and a programme of intensive pest and weed control, planting in the foothills and natural regeneration in the valleys has begun.

This is by far the most ambitious phase of the project to date, aiming to restore 100 hectares of hill country (marked in yellow below) as a haven for locally extinct indigenous species of birds, plants and animals, including brown kiwi, weka, robin, tomtit, kakariki, kaka, rifleman, East Coast kaka beak and broom, forest and green gecko.

This will be the largest fully protected area in the Tai Rawhiti region (from Opotiki to Wairoa, including the hinterland) with the sustained predator and weed control that allows these species to survive and flourish.

During 2011, a small predator-free enclosure was built in the hills, and five titi chicks were successfully translocated and reared, and flew off to the Pacific [see attached report]. During 2012, ten chicks were reared at Longbush, and flew off on their migration.

These are the first steps towards establishing an inland titi [grey-faced petrel] colony at Longbush - a world first. Although titi and other seabirds were a traditional source of guano to feed the native plants and trees, inland colonies of titi (once numerous) are now rare in New Zealand.

A predator-free fence in the Waikereru hills for kiwi, kakariki, kaka and rifleman is also planned, with a kiwi creche behind the Welcome Shelter – the Longbush Kiwi Haven.

View from the ridgeline