He resolved to complete it, but first he needed several thousand seedlings. He set about restoring an abandoned plant nursery behind DoC's Kerikeri headquarters, learnt how to propagate plants, and gathered a team of volunteers.
Once replanting of Motupapa (Cocked Hat Island) was complete he started on Motukawanui in the Cavalli Islands; now his main focus is the Bay of Islands, where replanting of Waewaetorea Island was completed in 2012 and the volunteers are hard at work this winter on Urupukapuka and Moturua islands.
As well as growing the seedlings, Mr Brown organises regular planting days in which up to 100 volunteers head out to the islands to lend a hand.
The Shadehouse produces about 25,000 shrubs and trees a year for 35 different restoration projects from Leigh to Cape Reinga. The number grown to date is just under 250,000.
Mr Brown is also deputy chairman of Guardians of the Bay of Islands, a group which, along with DoC and Rawhiti iwi, is restoring the islands sprinkled between Russell and Cape Brett. Called Project Island Song, the ambitious community-driven project aims to bring back the islands' original plants, birds and insects.
DoC rid the islands of rats in 2009 and the Shadehouse team have planted tens of thousands of trees, paving the way for last year's re-introduction of the toutouwai (North Island robin) and the return just last month of the tieke (saddleback).
If that was not enough Mr Brown also chairs the community planning group Vision Kerikeri. That group's projects include creating a public walkway to a spectacular but currently inaccessible waterfall a short distance from the town centre, and creating a wildlife corridor further up the same stream.
Mr Brown said it was his firm belief that people should not sit back and wait for an under-resourced DoC or councils to act when something needed doing.
He also believed the best thing councils and government agencies could do was to support initiatives that came from the community.
"The best outcomes are achieved when the community organises itself - and if you're willing to help yourselves, you will get support," he said.
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