What is the largest living organism in the world?
A blue whale?
No, it is not an elephant, or a blue whale. It is, Armillaria mellea, a species of Honey Fungus.
Could it be true that this small fungus could be the largest living creature in the world?
Yes, it is true.
Researchers in the US found the fantastic fungal colony shown above in the Malheur National Forest in the Blue Mountains of eastern Oregon. It is growing through the earth and roots of trees, covering 890 hectares (2,200 acres) of land – an area equivalent to about 1,220 football pitches (2003). From 2003 to 2007, the fungus has spread across an area equal to 1,600 football fields. But experts predicted the massive fungus could lose a significant portion of its mass if it falls victim to a major nature fire.
Honey fungus is a very destructive forest pathogen. It is known as a ‘white root’ fungus, and will attack the roots of a wide range of trees, shrubs, and woody climbers. Are they worth to be considered in conservation?
Definitely yes. As a part of biodiversity, they have a right to live in their own way.
Honey fungi are lucky because they grow big enough to catch people’s attention. Compared to honey fungus, most other fungi are not so lucky. Fungi are perhaps the most unappreciated, undervalued and unexplained organisms on earth.
It is estimated that about 1.5 million fungal species exist, which is 5 times the number of plants species. Scientist believe that only 5% of all fungi have so far been discovered. For most of species, little is known about their biology. In contrast to the honey fungus, the majority of fungi are microscopic,and they do not usually produce structures that are visible to the naked eye.
The inconspicuous nature of most fungi means that they have not attracted much attention, and as a result, little is known about their biology. Similarly, their role in nature conservation has also been overlooked.
To date, fungi are not included in any international biodiversity agreements. The IUCU global Red-list comprises about 45,000 species; however, there are only three fungalspecies listed. Does this mean that fungi are not important and donot need any protection?
No. Fungi are fundamental to healthy ecosystems, and essential to the sustainability of biodiversity. They are needed to support the functioning of major ecosystems. For example, they are useful in litter decomposition, nutrient cycling and energy flows in ecosystems. Moreover, the transition of nutrients from soil into plants also relies on the help of fungi, mainly mycorrhizal fungi. Nearly 97% of plants have symbiosis with mycorrhizal fungi. Can you image the situation without them?
While most of our attention has been directed toward the role of animals and plants in biodiversity conservation, we may have missed some other important agents influencing ecosystem biodiversity.
We should not ignore fungus just because most times we cannot see them. When considering ecosystem biodiversity, we should take into account the roles of all organisms so that any action we take to conserve biodiversity will be effective.
Dahlberg, A., Genney, D.R. & Heilmann-Clausen, J. 2010, “Developing a comprehensive strategy for fungal conservation in Europe: current status and future needs”, Fungal Ecology, vol. 3, no. 2, pp. 50-64.
Dreisbach, T.A., Schmitt, C.L., Ferguson, B.A., Filip, G.M. & Parks, C.G. 2003, “Coarse-scale population structure of pathogenic Armillaria species in a mixed-conifer forest in the Blue Mountains of northeast Oregon”, Canadian Journal of Forest Research, vol. 33, no. 4, pp. 612-623.
Mueller, G.M. & Schmit, J.P. 2007, “Fungal biodiversity: what do we know? What can we predict?”, Biodiversity and Conservation, vol. 16, no. 1, pp. 1-5.