Natures wonders: lichens mine rock (Introduction)

by David Turell , Friday, November 06, 2015, 00:45 (3304 days ago) @ David Turell

As they break down rock, they become a very important part of the balance of nature:-http://blogs.scientificamerican.com/artful-amoeba/the-world-s-largest-mining-operation-is-run-by-fungi/?WT.mc_id=SA_DD_20151105-"But why would a fungus tunnel into a rock? There's no food there, and it no doubt takes a sizeable capital investment to assemble and secrete the acids necessary to eat raw rock.-"There is a precedent: lichens. The crusty creatures, a combination of fungi, algae, and attendant bacteria/archaea, are the first and last word in Earth-based rock colonization. Wherever naked stone is found, lichens will be there.-***-"The fungal half of lichens are the drilling specialists, excreting acids that break down rock and enable the fungus to get a hypha-hold in micro-trenches, cracks, and etch pits (small lens-shaped cavities formed by the action of water). The acids are derived from the food that the algae provide to the fungus.-***
"Scientists have long known that mycorrhizal fungi - those that live symbiotically in and on the roots of plants - trade minerals and water they absorb from the soil for food that plants manufacture from sunlight, carbon dioxide, and water.-***-"Taken together, these traits mean fungi can probe and penetrate crevices that roots and root hairs cannot. Thus by partnering with fungi, trees can make use of a much larger soil volume than roots alone could do, and can consequently absorb more water and nutrients than trees without fungal partners.-"Ectomycorrhizal fungi hold up their end of the deal by secreting acids that dissolve mineral particles from a distance. Via special digestive proteins called enzymes, they can also access organic forms of nitrogen and phosphorous in the soil (like amino acids, peptides, proteins, amino sugars, chitin, and nucleic acids) that plants wouldn't otherwise be able to exploit. But there is a lot of other competition in the soil for these nutrients -- from other fungi, from bacteria, and from protists.-***-"Fungal mining has many advantages. Some feldspars contain pockets of apatite, a major source of phosphorous in forests. By excavating these otherwise locked nutrient chambers, fungi are able to access a phosphorous source that would be unavailable to plant roots alone.-"Fungal tunnels and the acids used to make them also speed up mineral decay and increase mineral surface area available directly to plant roots. Futher, fungal mining cuts off competition from other soil microbes for nutrients by accessing minerals in seclusion directly at the source. And it provides trees access to minerals even in acidified soil (the product of decades of acid rain), which can make grabbing them straight from the soil more difficult chemically.-Comment: How did all these guys get together to develop this complex balance of nature which makes soil from rock and helps with nutrition in so many ways? Not chance. Remember all land on Earth started as rock. Soil came later. Looks like god planning to me.