Just like humans, trees have a microbiome
The bacteria in and on our bodies – our microbiome – influences nutrition, obesity and our vulnerability to disease. A microbiome is simply the community of microbes that lives on and in an organism. Every person's body is home to a complex microbiome weighing about as much as a human head, and it's one of the hottest scientific topics around right now. So hot that President Obama has launched a so-called scientific ‘moon shot' initiative to figure out exactly how human microbiomes affect health and happiness.
Plants have microbiomes, too
Is a plant's microbiome just as important to the organism's health and well-being? After all, plants don't move and may need to rely on partnerships with communities of microbes to help them get nutrients. The early signs are promising. In May a team at the University of Washington, USA, revealed how poplar trees found in a rocky, inhospitable place contain a microbiome which helps provide the nutrients they need to grow. It looks as though microbiomes play a vital part in much more than just human health.
The findings could have profound effects on agriculture and bioenergy crops, improving productivity. On the other hand, just like humans, the microbial communities individual trees contain are incredibly diverse, varying beyond recognition in plants growing next to one another in much the same way as your own personal microbiome will differ from that of your colleagues, family and neighbours.
You don't need root nodules to fix nitrogen
This dramatic variation makes it difficult to draw sensible conclusions and quantify the microbes' activity, but it's clear that nitrogen fixation – a natural process which sustains every form of life – happens thanks to the help of nitrogen-fixing bacteria.
Scientists already know that nitrogen fixation happens in bacteria-rich nodules on the roots of plants like soybeans, clover and alfalfa. But the belief that only plants with root nodules can benefit from this kind of symbiosis no longer holds. The new research delivers the first direct evidence that nitrogen fixation happens in tree branches without root nodules.
Boosting plant productivity naturally
The news has significant implications for crop plants. The same microbes the team has isolated from the wild poplars and willows they studied have been found to help corn, tomatoes and peppers thrive with less fertiliser, as well as trees. Knowing which microbes help wild plants thrive even though they're growing on nothing more than rocks and sand means forestry will depend less on chemical fertilisers, providing a natural way to boost plant productivity without having to use fossil fuels to synthesise fertilisers.
Article by The Rainforest Foundation.