A world dying beneath our feet

By SIMON COLLINS science reporter

If we are really concerned about preserving endangered species, Peter Buchanan says, we should look beneath our feet.

Spread underground, often stretching many metres from the trees associated with them, are the tentacles of hundreds of species of New Zealand fungi which are noticed only when they sprout an occasional mushroom or toadstool.

A new Department of Conservation report on New Zealand's threatened species lists 50 fungi among 360 mostly better-known creatures, such as the North Island Hector's (now Maui's) dolphin and the kakapo, that are "nationally critical" - critically in danger of dying out.

Dr Buchanan, a Landcare scientist at the Mt Albert Research Centre, says many other fungi failed to make the list only because no one has yet recorded them.

"It's in the tiny things that most of the country's diversity is," he said.

"Birds are wonderful - I keep birds, I love birds. But if you're into things that are at the fundamental root of lots of nature, then the microscopic things - fungi and insects - are where it's at."

Just one day after his wife, Roseanne, gave birth to their son, Fraser, last month, Dr Buchanan broke into his leave to keep his appointment with the Herald to outline why fungi matter.

"About 95 per cent of plants need fungi to actually get the nutrients from the soil," he said.

"The fungi derive nutrients from the plant through photosynthesis, but they have their threads out into the soil and the nutrients they extract are used by both the fungus and the plant."

Each mushroom or toadstool that sprouts to scatter its spores when the weather is right is just the visible tip of a vast network of underground feeding tubes.

"They are huge in biomass, but we don't see them until they produce this particular fruiting structure."

The Conservation Department list shows that an extraordinary number of New Zealand's native living things are threatened in one form or another.

These include 145 out of 202 bird species, 19 out of 45 freshwater fish and all four frogs.

Many New Zealand species such as the frogs, the tuatara lizard and the common wolf spider are "living fossils" which have survived in these isolated islands for millions of years after their nearest relatives elsewhere died out.

Native fungi have become increasingly endangered as the bush that once sheltered them has been destroyed by humans and our associated pests such as rats, stoats and possums.

Our largest known threatened fungus, a woody species of Ganoderma known as "Awaroa" after a scenic reserve on the edge of Mt Pirongia west of Te Awamutu, has been found only in that area, hosted by the pukatea tree.

Landcare holds the only three known samples, the most recent from 1972, and in repeated searches of the area Dr Buchanan has been unable to find any others still living.

"It may be extinct," he said, "but I have trouble accepting that a fungus is going to go extinct within our lifetime, because fungi produce masses of spores.

"You have to have two spores that are compatible before you get a new fruit body formed. Nevertheless, I just have trouble accepting it has gone extinct because it would be tragic to lose it entirely."

University of Auckland student Rebekah Fuller, of the northern iwi Te Rarawa, is working partly under Dr Buchanan's supervision to record traditional Maori uses of native fungi.

"In Tuhoe they have one species they collect all the time, they know a lot about it and they really love it - a mushroom in decaying wood which they call harore, the same word for all mushrooms," she said.

Other uses have been lost: a vegetable caterpillar that was once mixed with black miro berry juice for ta moko (tattoos), and various fungi that were once eaten.

Many fungi are now being used around the world to make antibiotics, anti-cancer drugs and other medicines.

Dr Buchanan hopes places such as Pirongia which shelter endangered fungi may be fenced off from pests, along the lines of Wellington's Karori sanctuary and a $12 million Waikato project to build a pest-proof 45km fence around Maungatautari mountain.

On the web

biodiversity

Landcare Research

Endangered species

76 bryophytes (mosses, liverworts)

76 vascular plants (flowering plants, ferns, trees, etc)

72 terrestrial invertebrates (insects, spiders, moths, beetles, snails, etc)

50 fungi

13 birds

12 marine invertebrates (octopus, mussels, worms, etc)

4 freshwater invertebrates (water snails, etc)

3 marine mammals

3 reptiles

2 frogs

1 freshwater fish

(plus 48 subspecies)

Source: Department of Conservation