Horizons Regional Council staff were joined by a range of parties at an infill planting day for Betty Tripe Reserve in the Rangitīkei District at the end of last month.
Horizons biodiversity adviser Neil Gallagher says the 4ha reserve is a site of biodiversity significance as it includes numerous mature native trees.
However, there were holes that needed to be filled, he said.
"With help from the landowners, Rangitīkei District Council staff, Forest & Bird volunteers, iwi and interested locals we got 4000 natives planted to fill a significant gap in the bush," Gallagher said.
"This infill planting is a way to restore the forest by regenerating native species, increasing the amount of habitat that provides food supplies for native birds and insects, and reducing space for pest plants to establish.