We may be aware of the conservation problems facing kiwi, tuatara, hoiho (yellow-eyed penguin), kākāpo and black robin, but what do we know about the unique challenges faced by New Zealand fungi?

How big is the problem?

New Zealand maintains a list of species that are under threat or are at a high risk of becoming extinct. What many people are unaware of is that 13% of the threatened species on that list are fungi.

In 2002:

  • 50 species of fungi were named in the highest threat category – nationally critical – which means that they have a very high risk of becoming extinct in New Zealand
  • 16 species were listed as nationally endangered or nationally vulnerable.

A further 1,455 different species of fungi were unable to be classified due to a lack of information or data, so we don’t know if they are threatened or not. Many of these species could be threatened through habitat loss, or they may exist in populations that are very small or are declining fast. It is very important that scientists identify and monitor these species to find out whether they need protecting and conserving.

Why conserve fungi?

The idea of conserving a fungus, slime or mould might make you think “Yuk!” These organisms cause disease, threaten the crops that we grow for food and are just not very attractive. Why should they be conserved?

Fungi are an important part of any ecosystem as they help plants to absorb nutrients and recycle waste materials back into the food web. Many fungi are specialised and only feed on one type of plant. Often the loss of one species may affect a whole food web.

Fungi also support the growth of plants through symbiotic relationships. The beech forests of the South Island contain a number of species of Nothofagus (southern beech tree). Associated with the roots of these trees, and helping them to absorb minerals, are several species of the fungus Russula. There are 37 different species of Russula fungi in New Zealand – seven are identified as being nationally critical and are at very high risk of extinction.

If these fungi become extinct, the trees are at risk. Without this symbiotic relationship with fungi, the tree cannot absorb minerals and its health may be affected. In turn, this affects the huge numbers of species that use the tree as a house or a food source – one small symbiotic fungus can be very important.

What’s the dilemma?

Fungi pose a conservation dilemma about the merits of conserving a particular species. Many fungi are associated with disease, particularly plant diseases. If the host plant for the fungi is endangered, should the plant, the fungi, or both be conserved?

One New Zealand fungus that is critically endangered is the pathogenic (disease-causing) Puccinia embergeriae, which only feeds on the Chatham Islands sow thistle. The host plant is listed on the nationally endangered list and is earmarked for conservation. Should we be preserving the fungi that lives on this plant, even though it causes disease?

Nature of science

Scientists are a product of their culture and society. In New Zealand as a society, we value our uniqueness because we have an environment that is worth preserving. New Zealand scientists reflect these values.

 

    Published 30 April 2009