"Things flower and fruit at different times, so we need to make sure that the right food source is in the habitat throughout the year."
She said pioneer species provide protection from wind and sun for the more sensitive species, many of which grow into the more important food trees.
"So once the pioneers get big enough, we need to interplant with the other plants that will provide the rich tapestry required to make the habitat work permanently for the species we want to attract."
The group, which numbers around 12 and began in 2003, meets every Wednesday morning from nine till noon and is always looking for more people.
Supported by Greater Wellington Regional Council, the volunteers have potted and planted thousands of trees and the results are noticeable.
"Because we have only recently started enrichment planting, there are already a lot of areas containing pioneer species that are mature enough to interplant amongst, so we're growing the right trees as fast as we can and have quite a busy planting schedule in the winter."
Ms Burton Bell said mostly what we see when we look across the park is paddocks, which is a far cry from what it was before it was drained and farmed.
"The landscape would have included lots of shallow wetlands between dunes and the front dune by the beach would have been much lower.
"Now we look at a place that often looks dry and we think of plants that like dry, but actually this land would have been a mix of dense coastal forest, wetlands and peat swamps.
"We know this because Maori used it as their food basket and used to canoe through these swamps between Paekakariki and Foxton.
"I'd love to be able to provide people a glimpse of the richness of such an environment, even if on a small scale."
The Friends' AGM, which starts at 7.30pm in the Paraparaumu Library meeting room, will also hear from principal ranger Wayne Boness about GWRC plans and from environmental consultant Peter Handford about low-cost planting trials run by his company Groundtruth.
The meeting is open to members of the public interested in becoming involved in the Friends trust, which is the community's main voice in the management and care of the park.