ecosystem importance: soil dwelling organisms (Introduction)

by David Turell , Wednesday, October 25, 2023, 21:05 (393 days ago) @ David Turell

The inhabitants make our rich soils:

https://evolutionnews.org/2023/10/hidden-service-animals-earthworms-are-only-the-beginn...

"Without earthworms, scientists at Colorado State calculate, we would have 25 percent less food productivity from plants. How much food service do they provide for us? About 140 million metric tons is the estimate.

"Earthworms help establish healthy soils by supporting plant growth in multiple ways — building good soil structure, assisting in water capture and aiding in the beneficial churn of organic matter that makes nutrients more available to plants. Other research has also shown that earthworms can facilitate the production of plant-growth-promoting hormones and help plants protect themselves against common soil pathogens.

"These services are delivered by soft, squishy annelid worms that are easily crushed. The soil is their dark utopia. Moving about with radial and longitudinal muscles, they “worm” their way through each crevice, plowing the soil in a way that helps plant roots navigate to nutrients the worms have made available.

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[A picture of muscles] "They are impressions of radial worm muscles just 1 millimeter in diameter. The structure allows the muscles to “introvert” like a plunger as the worm stretches and squeezes. They are works of art.

"These particular muscles are not from earthworms (annelids) but from cycloneuralians, “a group of animals that includes roundworms, horsehair worms, mud dragons, and many other creatures.” This kind of structure is required for worms to navigate through the tight spaces in their environments. And they were detected in fossils from the early Cambrian!

"In this study, the researchers described three phosphatized and millimeter-sized specimens from the early Fortunian Kuanchuanpu Formation (ca. 535 Ma) of China. Among them, one specimen (NIGP179459) is better preserved, and consists of five successively larger rings that are interconnected with 19 radial and 36 longitudinal structures. The rings were compressed to certain degrees, implying that they were pliable when alive.

"Muscles imply nerves and coordination by a central nervous system. A diagram further down in the article shows the arrangement of seven kinds of radial and longitudinal muscles. The musculature in annelids (which also abruptly appeared in the Cambrian Explosion) is no less wondrous. (my bold)

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“This work supports the evolution of scalidophoran-like or priapulan-like introvert musculature in cycloneuralians at the beginning of the Cambrian Period.” (my bold)

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"Soil organisms mediate unique functions we rely on for food, fiber, and human and planetary health. Despite the significance of soil life, we lack a quantitative estimate of soil biodiversity, making it challenging to advocate for the importance of protecting, preserving, and restoring soil life. Here, we show that soil is likely home to 59% of life including everything from microbes to mammals, making it the singular most biodiverse habitat on Earth. Our enumeration can enable stakeholders to more quantitatively advocate for soils in the face of the biodiversity crisis. (my bold)

"This is twice previous estimates for soil biodiversity. Some 98.6 percent of annelids live underground; other species include fungi, plants, and isoptera (termites). The services they provide to the biosphere are incompletely understood. In a companion piece in PNAS, Richard Bardgett remarks about the new estimate:

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"...the estimate that 59% of all species inhabit soil, with several taxonomic groups being almost entirely soil-based, points to soil being the most speciose, but poorly explored, habitat on Earth. This staggering level of species richness in soil, combined with growing awareness of the functional importance of soil biodiversity for supporting ecosystem services, their resilience to environmental change, and of its sensitivity to multiple global change factors, provides a strong basis to advocate for explicit inclusion of soil biodiversity in international strategies for biodiversity conservation and the protection of threatened soil species.

"...it’s a sobering thought to realize that much of our livelihood depends on hidden service animals under our feet.

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"Free-living organisms and microbes that live their lives on and in the ocean’s top meter of seawater are thought to play vital roles in ocean ecosystems, nutrient cycles, oxygen production, the carbon pump, and other earth processes. Yet, surprisingly, relatively little is known about these vital marine communities — collectively known as neuston — their evolution, how they develop, how they affect their environment, and how their environment affects them."

Comment: dhw take note. God planned for our food supply back in the Cambrian. God knows what He is doing. dhw has no idea, except to criticize God's choice of action.