Discovering a whole new universe in the soil
The intricacies of soil biodiversity may offer scientists insights into how species — animals and plants — can survive global warming.
Fri, Jun 14, 2013 at 05:45 PM
Microscopic organisms that thrive in soil. (Photo: D. Bignell)
When Dr. Diana Wall flew to the Antarctic to study soil life, she wasn't sure what to expect.
“The literature had said that there was life near the streams. It had even described three species of nematodes. But it was thought that there was nothing in the vast expanse of desert soils away from the melt streams,” she said.
Yet as Wall and her team began testing their soil samples, they discovered hardy species of nematodes surviving in about 60 percent of the arid, desert soils, well away from any bodies of water. (The 40 percent of soils that did not contain life were simply too saline to support it.)
Wall’s work has had profound implications, not just for soil science in Antarctica, but for our understanding of the nature of soil itself.
All soils are not the same
Soil has long been thought of as somewhat of an equalizer.
Above ground, we see a broad diversity of plants and animals, varying greatly from climate to climate and region to region. But below ground, soils were very much alike — or so it was believed.
Sure, some were acidic and some were alkaline. Some contained more organic matter, some less. But by and large the organisms and materials that made up the soil, or “dirt” as it is too often called, were considered relatively uniform.
Thanks to pioneers like Wall, however, we now know that nothing could be further from the truth. As a recent article by Jim Robbins in the New York Times explains, soil may actually be one of the great overlooked bastions of biodiversity:
“Scientists using new analytical techniques over the last decade have found that the world’s ocean of soil is one of our largest reservoirs of biodiversity. It contains almost one-third of all living organisms, according to the European Union’s Joint Research Center, but only about 1 percent of its micro-organisms have been identified, and the relationships among those myriad life-forms is poorly understood.”
This bastion is now increasingly at risk.
The new understanding of the complexity of soil, says Wall, is driving a shift of both the scientific and cultural paradigm:
“For many hundreds of years, we’ve simply thought of soil as providing us food. That’s been our cultural tie. Because of the research over the last 20 years, and the new technologies we’ve developed, we’ve learned that the processes going on underground are deeply complex. Just as we have ecosystems above ground, so too we see ecosystems below ground, each with their own unique conditions and mix of species. Whether you’re in Central Park or the Antarctic desert, its almost like we have lots of miniature cities beneath our feet. The science shows that this is very far from being just 'dirt'.”
The shift in how we view the soil is already translating into changes in how we manage it. From the rise of SRI methods of rice growing among small farmers to no-till farming on the giant fields of the Midwest, farmers are realizing increased yields and lower inputs of chemicals and fertilizers by learning to manage and steward the soils they are responsible for.
Diana Wall gathers soil samples in Antarctica. (Photo: Wall Labs)
Losing what we have not yet discovered
With so few soil micro-organisms identified or properly studied, it’s anyone’s guess how many species have already been lost. Pressures from climate change, desertification, intensive agricultural practices and urbanization mean the habitat of soil dwelling-creatures is changing and/or being lost at an astounding rate.
Wall is now spearheading the Global Soil Biodiversity Initiative – an effort to both map soil diversity across the world (including an intensive study of soils in Central Park) and develop robust evidence-based policy to protect and restore it.
That protection will become increasingly important, says Wall, as the unpredictable process of climate change unfolds all around us. In fact, advances in soil science are causing a radical rethink of how and if above ground plants and animals will be able to adapt to a shifting climate too:
“Plants have a “home field advantage” when they grow where they have always grown, with the soils and soil organisms they are used to. There’s been plenty of discussion about what plants and animals will survive in what climate, and where. But we’re not just talking about whether this palm tree, or this wheat cultivar, will survive in a new climate anymore. We have to also look at whether the soil organisms it has co-evolved with will be there too.”
Honored for her work
Wall’s work has been honored with the Tyler Prize for Environmental Achievement, a prestigious award given by the Tyler Prize Executive Committee and administered by the University of Southern California that brings with it a $200,000 cash prize, a gold medallion and, most importantly, a huge boost in awareness of this important work. (Previous laureates include Jane Goodall, E.O. Wilson and Jared Diamond.)
“I still think about it and I have to pinch myself. To think that I would be that widely recognized for my Antarctica work, and all this biodiversity work, is astounding. I thought I was this lone voice with a few colleagues to talk to. But it’s kind of like a pat on the back, and a push to keep doing more. Now they’ve given me this opportunity, I have to step up and keep raising awareness of all these soil issues we face. Of course, with the funding environment being what it is, it also gives me a nice safety net to know that I can keep things moving if I have to.”
With the threat of climate change unlikely to disappear any time soon, many of us will be hoping that Wall and her colleagues do indeed keep expanding our understanding of soil life and what we can do to nurture it.
We’ve lost too much already. It’s time to protect the soils we rely on for survival.
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