Restoring a gully on your property will bring rich rewards, says Leo Koppens. Venetia Sherson talks to him about his passion …
By his own admission, Leo Koppens is an environmental terrorist. His enemies are willows, wandering dew and blackberry; his weapons, weed killer, slashers and chainsaws, plus a sturdy pair of boots. If he wins the battle, the gully networks in Tamahere and Matangi, south of Hamilton, will again become forests of mighty kahikatea, totara and kauri, filled with the songs of tui and bellbirds.
He won’t see it happen, of course.
“We are laying the foundation for what will happen. It won’t be in my time, but it will be in my grandchildren’s time and beyond,” he says.
Koppens has been restoring gullies for 35 years. His story began on his own property at Tamahere, where his family have lived and worked since 1970. A 1.5ha gully on his land was unproductive, grazed by sheep but steep and deeply rutted. Koppens – encouraged by a gardener friend – saw the opportunity to restore the steep-sided landscape to how it would have been.
He said there was no “grand plan” initially. “I put kahikatea at the bottom where it was wetter and planted kauri and southern beech.”
It was impossible to get machines down the slopes so all the clearance was done by hand. “There was a lot of hawthorn and massive poplars lying down there. When we cleared it, the blackberry moved in.”
The clearing and planting took years and was completed at weekends and after work. By 1975 it was well underway. Today the kahikatea have reached a size where Koppens can just circle the trunks with his arms.
Native birds have shown their gratitude by taking up residence and tui are now breeding in the gully. Koppens is hoping wood pigeon (kereru), shining cuckoo (pipiwharauroa), bellbirds (korimako) and even kaka will follow. At night, the morepork are prolific. “We just need critical mass; more plantings to encourage them to come.”
Koppens would love more people to develop gullies on their land. He says many property owners are daunted by the prospect of clearing and replanting a gully. “But it’s a simple thing to strip the land of all undesirables. In five years time you could be fully planted.”
As a real estate agent, he says there are also good commercial reasons to develop gullies on private properties.
“There is enormous added value for a property that has a restored gully with a path running through it. A gully full of blackberry is like a swimming pool full of frogs. Much better to develop it to its best potential.”
Koppens’ motive is not commercial, however:it is environmental. He says much of the gully network is being overrun by willows and weeds such as wandering dew, which clog waterways. “To do nothing is not an option.”
An example is the 10ha Mangaone gully, which flows for 3km parallel to SH1 in Tamahere. The gully is thought to be one of the few places where an all-but-vanished ecosystem could be restored, including stands of ancient kahikatea swamp.
But sediment that should be going out to sea is trapped by willows, drowning the natives.
Koppens says 50 private properties border the gully. “If each [owner] did their own little bit, it would be a wonderful result. The majority of these properties have around 100sq m of gully, which is not a big area.” The impact on birdlife would also be substantial.
A management plan for Mangaone gully, involving the council and property owners is scheduled for 2013. But it could take 20 years to come to fruition.
Koppens is now working on a project at the Tamahere Reserve, what he describes as a “daunting weed-invested” area of some 5ha of pine-cum-wetlands. “I had to crash my way in. The privet was bad, plus blackberry and honeysuckle. There was a huge infestation of wandering dew but, fortunately, well away from the waterway.”
He and one or two other volunteers are chipping away, clearing willow and weeds and replacing them with natives. Every piece of timber has to be carried some 200-300m by hand to higher ground. There are five different tree ferns and pate (schefflera)forming a dominant canopy. About 450 plants have been planted and other plants moved to more suitable locations. He thinks the kahikatea will withstand the wetness underfoot. “Some of the kahikatea there are around 400 years old.”
Within five years, he says, it will be a wonderful walk alongside the stream. The banks will be planted with totara, titoki, matai, pukeatea and karaka.
Koppens knows the pleasure people gain from gully experiences by the responses of his grandchildren to the gully on his and his partner Philippa Stevenson’s property.
“They love the gully – and the taniwha that live there. It is a magical place.”
He says he will continue to work on restoring gullies for as long as he is physically able.
“One volunteer is in his mid-70s, so I reckon I’ve got at least another 10 years.”
Click here for resources and information about gully restoration.