Hawke's Bay's Pekapeka wetlands. A data-packed interactive map has been launched to support ecological restoration efforts across New Zealand. Photo / Warren Buckland
Kiwis can now explore what their local biodiversity might have looked like in a land unspoiled by humans, with an interactive tool to help New Zealand rebuild its lost flora and fauna.
Launched today, the richly layered “Eco-index” map was developed to support efforts toward restoring natural ecosystem cover to a minimum 15 per cent in every catchment in the country – and within a century.
Stocktakes have shown how less than half of our land area remains covered with native vegetation, while, of nearly 11,000 species, around a third are ranked as either threatened or at risk.
When it came to saving what native ecosystems we still had, studies have suggested that safeguarding at least 15 per cent of their natural range was critical: Below that level, the number of species they could support fell away dramatically.
“So, we made it into a long-term goal,” the Eco-index project’s co-lead, Dr Kiri Joy Wallace, said of the target.
“In some areas, this requires reconstruction of native ecosystems through ecological restoration efforts like fencing, planting and pest control.”
In areas where that 15 per cent still existed, protection was key.
The index, initiated through the collaborative Biological Heritage National Science Challenge, showed that, in many places, native biodiversity had dwindled to well below levels ecosystems depended on to function.
Wallace described an Aotearoa once cloaked with forests, herb fields and wetlands – all home to diverse and flourishing communities of plants, animals, invertebrates, and fungi.
“Human-driven replacement of these ecosystems with non-native or mixed-origin land uses means that native ecosystems now exist in a patchwork of fragments that are much smaller than their expected natural range, especially in lowland areas.”
Large tracts of native ecosystems supported more native species than small, fragmented patches could.
For those species at the edge of extinction, restoring their local habitats wasn’t as simple as planting more general greenery.
A coastal area could be planted in harakeke, for instance, but it was more appropriate to restore the rare coastal grassland that once thrived in that location and didn’t grow in many other places.
“If we want to reverse the decline of native biodiversity in this country, ecological science suggests that restoration of ecosystems in every catchment is an important step,” Wallace said.
“This is because there are many ecosystems that naturally occur in only a few catchments; think about the difference between alpine herb fields in the Southern Alps, wetland forest in Taranaki and dunelands in Northland.
“It is important to address the natural variety of nature across the motu as these different ecosystems are home to a wonderful array of native species.”
Eco-index co-lead Dr John Reid described the data-informed, catchment-by-catchment restoration targets accompanying the maps as the most “comprehensive and ecologically meaningful” to date.
“Land managers, decision-makers, community environmentalists, and policy-makers have overwhelmingly good intentions, but they still have lots of questions that we hope our new map will begin to answer.”
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.