Ever get bothered by conflicting statements or ideas? I do on occasion, and this is one of them. Here are two article titles I just saw on Phys.org, an ordinarily wonderful source of science news. Actually, the two titles make sense on their own, but juxtaposed on the same page, they appear contradictory. The first title is “Degraded Soils Mean Tropical Forests May [might?] Never Fully Recover from Logging.”* The second is “Hard as a Rock? Maybe not, Say Bacteria That Help Form Soil.”** Huh? Remember that first title: “May [properly “might,” no permission required] Never Fully Recover.” Now, if you aren’t a farmer, gardener, or agronomist, you might question the relevance of either article to your life. So, here’s a bit of a background before I make a rather obvious point.
Soils can be very complex and layered aggregations of bits of mineral matter, decaying organic matter, water, gases, and living organisms. They were not contemporaneous with the earliest Earth. They formed over time. And then they were destroyed, and formed again, and were destroyed again, and then formed again…. You get the picture. Since the Great Bombardment of Bolides ended about 3.8 billion years ago, Earth’s surface has undergone a cycle of soil formation and destruction (or burial and lithification).
Here’s a sentence from the second article. “Research published this week by University of Wisconsin-Madison scientists shows how bacteria can degrade solid bedrock, jump-starting a long process of alteration that creates the mineral portion of soil.”* So, it seems that as long as Earth has rock at its surface and bacteria, soils will, in fact, recover. And shortly after life took hold on this planet—maybe contemporaneously with that cessation of major meteorite bombardment—this planet has belonged to bacteria. They’ve been discovered as deep in the crust as the gabbroic layer below the seafloor of the Atlantic Massif.*** They live in the depths of the Mariana Trench, as well.**** And they live all over and throughout your body. Earth is the Bacteria Planet, and you, like its water and rock, are a mere repository, a condo for microbes.
Soil recovery is a slow process, however, too slow for a particular farmer or forest to await its completion. That means with respect to humans currently alive, depleted tropical rainforest soils will not naturally recover, so the premise of the first title above is, practically considered, correct. But the processes that form and destroy soils are, in fact, ongoing. Mechanical and chemical weathering, coupled with biochemical weathering by lichens and in conjunction with bacteria and burrowing organisms like mammals, insects, and worms continuously work to keep segments of Earth’s surface covered by that thin veneer of ever-renewing soil.
If you don’t eat, you might ask, “Who cares?” but you probably do eat. We’d be hard pressed to grow food—though it is hydroponically possible on a small scale—without soils. With more than seven billion people currently alive, soils are indispensable for humanity’s survival. Our lives depend on soils—and on bacteria. And that brings me to this: That which we take for granted or ignore can play a role in our very survival. We are all supported by processes, materials, and even people in ways we might not recognize.
Look around.
*https://phys.org/news/2019-12-degraded-soils-tropical-forests-fully.html
** https://phys.org/news/2019-12-hard-bacteria-soil.html Accessed December 16, 2019. Original article: Stephanie A. Napieralski et al., Microbial chemolithotrophy mediates oxidative weathering of granitic bedrock, PNAS (2019) www.pnas.org/cgi/doi/10.1073/pnas.1909970117
***Mason, Olivia U. (2010). First investigation of the microbiology of the deepest layer of ocean crust. PLOS/ONE. 5 Nov 2010. Online at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0015399 Accessed December 18, 2019.
**** https://www.newser.com/story/203185/earths-deepest-spot-is-alive-with-unexpected-bacteria.html
Soils can be very complex and layered aggregations of bits of mineral matter, decaying organic matter, water, gases, and living organisms. They were not contemporaneous with the earliest Earth. They formed over time. And then they were destroyed, and formed again, and were destroyed again, and then formed again…. You get the picture. Since the Great Bombardment of Bolides ended about 3.8 billion years ago, Earth’s surface has undergone a cycle of soil formation and destruction (or burial and lithification).
Here’s a sentence from the second article. “Research published this week by University of Wisconsin-Madison scientists shows how bacteria can degrade solid bedrock, jump-starting a long process of alteration that creates the mineral portion of soil.”* So, it seems that as long as Earth has rock at its surface and bacteria, soils will, in fact, recover. And shortly after life took hold on this planet—maybe contemporaneously with that cessation of major meteorite bombardment—this planet has belonged to bacteria. They’ve been discovered as deep in the crust as the gabbroic layer below the seafloor of the Atlantic Massif.*** They live in the depths of the Mariana Trench, as well.**** And they live all over and throughout your body. Earth is the Bacteria Planet, and you, like its water and rock, are a mere repository, a condo for microbes.
Soil recovery is a slow process, however, too slow for a particular farmer or forest to await its completion. That means with respect to humans currently alive, depleted tropical rainforest soils will not naturally recover, so the premise of the first title above is, practically considered, correct. But the processes that form and destroy soils are, in fact, ongoing. Mechanical and chemical weathering, coupled with biochemical weathering by lichens and in conjunction with bacteria and burrowing organisms like mammals, insects, and worms continuously work to keep segments of Earth’s surface covered by that thin veneer of ever-renewing soil.
If you don’t eat, you might ask, “Who cares?” but you probably do eat. We’d be hard pressed to grow food—though it is hydroponically possible on a small scale—without soils. With more than seven billion people currently alive, soils are indispensable for humanity’s survival. Our lives depend on soils—and on bacteria. And that brings me to this: That which we take for granted or ignore can play a role in our very survival. We are all supported by processes, materials, and even people in ways we might not recognize.
Look around.
*https://phys.org/news/2019-12-degraded-soils-tropical-forests-fully.html
** https://phys.org/news/2019-12-hard-bacteria-soil.html Accessed December 16, 2019. Original article: Stephanie A. Napieralski et al., Microbial chemolithotrophy mediates oxidative weathering of granitic bedrock, PNAS (2019) www.pnas.org/cgi/doi/10.1073/pnas.1909970117
***Mason, Olivia U. (2010). First investigation of the microbiology of the deepest layer of ocean crust. PLOS/ONE. 5 Nov 2010. Online at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0015399 Accessed December 18, 2019.
**** https://www.newser.com/story/203185/earths-deepest-spot-is-alive-with-unexpected-bacteria.html
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