A new study has revealed that fungi, often seen as pests, play a crucial role policing biodiversity in rainforests. The Oxford University-led research found that fungi regulate diversity in rainforests by making dominant species victims of their own success. Fungi spread quickly between closely-packed plants of the same species, preventing them from dominating and enabling a wider range of species to flourish.
A new study has revealed that fungi, often seen as pests, play a crucial role policing biodiversity in rainforests. The Oxford University-led research found that fungi regulate diversity in rainforests by making dominant species victims of their own success. Fungi spread quickly between closely-packed plants of the same species, preventing them from dominating and enabling a wider range of species to flourish.
“In the plant world, close relatives make bad neighbours,” said Dr Owen Lewis of Oxford University's Department of Zoology, who led the study. “Seedlings growing near plants of the same species are more likely to die and we now know why. It has long been suspected that something in the soil is responsible, and we've now shown that fungi play a crucial role. It's astonishing to see microscopic fungi having such a profound effect on entire rainforests.”
“Fungi prevent any single species from dominating rainforests as they spread more easily between plants and seedlings of the same species. If lots of plants from one species grow in the same place, fungi quickly cut their population down to size, levelling the playing field to give rarer species a fighting chance. Plots sprayed with fungicide soon become dominated by a few species at the expense of many others, leading to a marked drop in diversity.”
The study, published in Nature, looked at seedling plots across 36 sampling stations in the Chiquibul Forest Reserve, Belize. It was carried out by scientists at Oxford University and Sheffield University and funded by the Natural Environment Research Council (NERC).
Researchers sprayed plots with water, insecticide or fungicide every week for 17 months. They found that the fungicide Amistar® dealt a significant blow to diversity, reducing the effective number of species by 16%. While the insecticide did change the composition of surviving species, it did not have an overall impact on diversity.
"We expected that removal of both fungi and insects would have an effect on the tree species," said Professor Rob Freckleton of Sheffield University, who co-led the study. "However what was unexpected was that removal of the fungi affected diversity, but eliminating insects didn't. Ours is the first study to unpick the effects of the different natural enemies."