Saturday, November 14, 2015

David R. Montgomery and Anne Biklé's "The Hidden Half of Nature"

David R. Montgomery is a MacArthur Fellow and professor of geomorphology at the University of Washington. He is an internationally recognized geologist who studies how erosion shapes topography and the effects of geological processes on ecological systems and human societies. Author of three award-winning popular-science books, he has been featured on NPR, BBC, PBS, CNN, MSNBC, Al Jazeera America, and Fox News programs, as well as in documentary films. When not writing or doing geology he plays guitar and piano in the band Big Dirt.

Anne Biklé is a biologist with wide-ranging interests that have led her into watershed restoration, environmental planning, and public health. An invited speaker at universities and national conferences on connections between public health and the built and natural environments, she has also worked extensively with community groups and non-profit organizations on environmental stewardship and urban livability projects. She spends her free time out in the garden with her hands on plants and dirt.

They applied the “Page 99 Test” to their new book, The Hidden Half of Nature: The Microbial Roots of Life and Health, and reported the following:
The page 99 test seems to work for The Hidden Half of Nature. An illustration with the title “Halo in the Soil” covers about half the page. This is a central theme of the book—that symbiotic relationships involving microbial life drive and sustain more complex life.

We subtitled the section leading up to the illustration, “The Power of Food” for good reason. Food underlies symbiotic relationships between a plant (and a person’s) indigenous microbiota—their microbiome. Plants use the near-insatiable appetite of microbes to their advantage. Through photosynthesis stuck-in-place plants make their own food, carbohydrates. A lot of them. Plants pump some of this food, along with other substances into the soil through their roots. These botanical concoctions are called exudates. When they flow herds of beneficial bacteria and fungi come running, as we write in text accompanying the illustration:
When soil scientists discovered that plants release nutrient-rich exudates into the soil, they were astounded. One review found that root exudates can account for 30 to 40 percent of a plant’s photosynthetic production of carbohydrates! That’s like a farmer setting a third of his harvest at the edge of his field for passersby to take for themselves. Why would plants give away such a bounty?
A plant’s root microbiome gives something in return to the whole plant—molecules and compounds that function as the bedrock of the botanical world’s health strategy. The microbiota that rush to lap up exudates at the surface of a plant’s roots use them to fuel their own manufacturing efforts. They make and release a range of metabolites for plants, among them growth hormones and precursor molecules. The latter become defensive compounds that plants use to thwart pathogens and herbivores.

Interestingly, the same type of master plan is at work in our bodies although the players are different. Deep down in the least-loved part of our digestive tract, the cells lining our root-like colon carry on incessant chemical exchanges with the human gut microbiome. Our well-being, it turns out, is intimately linked to the metabolites that our microbiome serves up. And as in the botanical world, our microbial allies rely, in part, on the exudates our colon cells produce. The human colon and the root of a plant are akin to biological bazaars in which the goods and wares exchanged between microbiome and host function as the backbone of a built-in health plan for people and plants.

This is astounding. Our microbial allies are as important in preventing disease as their pathogenic cousins are in causing it. The implications are enormous. We need to begin changing the agricultural and medical practices that have long been dismantling nature’s built-in health plan. For no less than our own health and that of our crops is at stake.
Visit The Hidden Half of Nature website.

--Marshal Zeringue