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Oxygen 30%
Oxygen 30%
Atmospheric oxygen content was a very rich, 30% cent in the early Permian period, compared with around 20% today. So where did it come from – and was it connected with bacteria?
Tree remnants were now being broken down more aerobically thus providing a lot of more nutritious breakdown products, to help grow the tall plants more. These would have been taking in more carbon dioxide (and water) to produce growth compounds - and oxygen.
Perhaps more porous the soil structures enabled better oxygen exchange near the surface, so an increase in oxygen there may have produced greater lignin decomposition, resulting in a further increase in humus recycling nutrients, that led to better plant photosynthesis, which in turn produce more oxygen? It is the cycle we are familiar with today, but then it would have been setting off.
2nd Wave of Decomposition
2nd Wave of Decomposition
This - second wave of decomposition - was a major step in soil evolution that has made a more complete carbon and energy cycles. Saprophytic fungi and aerobic bacteria had been decomposing for a hundred million years and in the process helping mineralisation.
Basically, the decomposition process during this Permian period developed one of the main components of decomposition - de-lignification. De-lignification became more widespread, probably evolving from saprophytic fungi to become white rot fungi (WRF) probably encouraged by the more aerobic conditions of where trees fell, and so enabled the breakdown of woody materials more thoroughly. See 'Wood Rot' for how.
In the one world of Pangea, trees did start to grow further away from the swamps, into the dry hinterland. Conifers can withstand both cold and dry conditions. You can see today where conifers are capable of growing – at the extremes of conditions up mountains on thin soil. They have strong roots growing sideways and grow very tall. You can see their strength when they grow under tarmac often lifting it up, When the trees fall, they then fell more on to dry land.
The aerobic bacterial and fungal processes could come into their own. Streptomyces and Rhodoccocus of Actinobacteria and Proteobacteria are typical aerobic bacteria for lignin degradation. Streptomycesviridosporus T7A decompose lignin by extracellular enzymes secreted by filamentous form.
Energy
Energy
This more complete decomposition released more energy
Now, more of that plant energy previously trapped as coal, was going into the soil metabolism. While coal was still being formed, there were also a lot of dry areas for soil evolution. As the trees lived in drier conditions, when they fell to ground there was more air, enabling the white rot fungi to thrive on the lignin, thereby releasing energy. All the creatures, chemicals, electrons need energy to live and move, and they would now have a greater supply. For more see Energy
How much?
A quadrillion kwH every million years
How much?
A quadrillion kwH every million years
The world ever after was charged with so much more energy. It could make massive trees and forests, and great big creatures, along with millions of flying insects. The energy for that has come from the sun, trapped by plants and passed on by soil. That 10 trillion tonnes of coal from 10,000 trillion tonnes of ‘organic sediment’ left over from the previous 25m years is an awful lot of organic matter that did NOT decay.
In terms of energy, my quick calculation (Each million years: 10 trillion tons X 2,500kwH - electricity produced from ton of coal - divided by 25 - million years of Carboniferous) and if the trees were as numerous as in the previous period, there would be about a quadrillion kwH of electricity to drive soil metabolism every million years. Coal production carried on, reaching a peak another 150 million later, but overall, there was much less coal production than previously.
Metabolic Energy
This energy could build new stronger bigger, more complex structures
Metabolic Energy
This energy could build new stronger bigger, more complex structures
Instead, lignin broke down and went into sediment, shale and soil and energy was released. This energy could build new stronger bigger, more complex structures, run many more creatures in the soil. Remember that energy needs to flow in to the system to keep it stable, but an increase in energy flow will have a recurring impact – it won’t be the same. As new bigger more plants grow, and animals on them, all get recycled in the soil now, surely that will lead to more plants and animals. But has anybody worked out the additive factor to arrive at the figure of how much energy is held in soil, plants, and animals?
Till this period, there was superficial layers, waste, shale and ash with much plant debris at the bottom of seas. Now there is a more complete life cycle of energy and mineral coming down from the plants, who get fed in exchange, which goes into the soil as proteins and saccharides. These helps build and provide energy to drive the soil food web. The creatures hold on to the carbon components, and generate oxygen while running round the underground architecture of the soil cities.
This provides the metabolic energy that has helped drive plant and animal growth. It would be another 100 million years to improve on this. Much of that movement on land, derives from energy in soil. Plants would not grow and animals could not feed without all that energy coming up from the soil, as the key in that energy cycle, started by the sun.
New Energy
search for fossil fuel alternatives
New Energy
search for fossil fuel alternatives
There are more studies of these de-lignifying bacteria these days, as their role in altering lignin in many commercial products could be beneficial (Lee et al., 2019). In the search for fossil fuel alternatives, much effort has been devoted to the discovery and development of microorganisms that can efficiently convert plant biomass into biofuels and commodity chemicals (Davis et al., 2013)
The biggest mass extinction in Earth history, around 250mya, was preceded by higher extinction rates before the main event and was followed by a delayed recovery that lasted for millions of years. It may be that a sharp decline in atmospheric oxygen levels was likely a major reason for both the elevated extinction rates and the very slow recovery. If so, we have to wander what happened to that oxygen cycle and its effect on soil.
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