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The concept of the Permian (299 million to 252 mya) was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia.
“The Late Paleozoic period (Permian) was the time of colonisation of land by diverse groups of plants and animals with the formation of a continuous soil cover" (Slater, McLoughlin and Hilton, 2015)
Pangaea
Pangaea
One of the key features of the Permian was the existence of the supercontinent Pangaea, where most of the Earth's landmasses were joined together. This configuration influenced the distribution of climates and soils.
After around 30-40 million years of crashing about, all the continents were now connected in Pangea. Pangea’s existence was first proposed in 1912 by German meteorologist Alfred Wegener as a part of his theory of continental drift. Pangaia is Greek – ‘pan’ for ‘all’and ‘gaia’ for ‘the Earth’. There is debate over to exactly when – from 330 to 280 Mya. Only 50 million years difference.
Pangea lasted for at least 175m years, during which time there were massive soil developments – all over the world. Many soil creatures today are the similar the world over. There is a similar processes in soil across the world, including artic and antarctica, some of which were added after the creation of Pangea. It implies that the ‘existing mesofauna’ we know today – the springtails, symphylans, diplurans and proturan, and mites were all around then. Fossil evidence for Pangaea includes the presence of similar and identical species on continents that are now great distances apart.’ However, earthworms and oribatids have more limited and distinct distribution worldwide, indicating their later evolution, as we will see later.
Developing Soils
Developing Soils
The Permian Period was characterised by diverse environmental conditions, including different types of soils. The Earth experienced significant climatic and geological changes, leading to the development of various landscapes and soil types.
The Permian climate varied widely, from arid to more humid conditions. In some areas, there were vast deserts, while others experienced more tropical or temperate climates. These climatic variations contributed to the development of different types of soils.
The specific characteristics of Permian soils would have depended on factors such as climate, topography, and vegetation. In arid regions, you might find sandy soils or even evaporite deposits from ancient salt flats. In more humid or vegetated areas, you could find a mix of organic-rich soils, clays, and other sedimentary deposits.
The Permian saw the evolution of various plant and animal species. The types of vegetation present in an area would have influenced the organic content and composition of the soil. Different types of plants contribute different organic materials to the soil, affecting its fertility and structure. Permian soils were also subject to various sedimentary processes. Rivers, lakes, and marine environments played a role in the deposition of sediments, leading to the formation of different types of sedimentary rocks and soils. But perhaps the most long lasting and crucial development was of White Rot Fungi which were able to break down the lignin in trees, thereby enabling better circulation of carbon and energy. I call this de-lignification the Second Wave of Decomposition
As a result, the types of soils and environments present during the Permian varied as evidenced from Palaeosols across the regions.
Deserts
Deserts
The period saw a massive desert covering the interior of Pangaea. Deserts seem to have been widespread on Pangaea. The warm zone spread in the northern hemisphere, where extensive dry desert appeared. The rocks formed at that time were stained red by iron oxides, the result of intense heating by the sun of a surface devoid of vegetation cover. A number of older types of plants and animals died out or became marginal elements. But others came in and were able to survive the drier conditions.
The interiors of the large continental landmass experienced climates with extreme variations of heat and cold - continental climate - and monsoon conditions with highly seasonal rainfall patterns.
Lignin Fuel
Lignin Fuel
This is the period of the first great carbon cycle. The soil biomass in this period increased dramatically, driven by lignin fuel. Plants were broken down mainly by aerobic fungi and bacteria, providing more nutrients for plants to grow bigger and stronger, and release more oxygen. The tall plants’ roots grew aggressively sideways, with associated mycorrhiza fungi to collect more water and nutrients, and produce vast amounts of glomalin which provided food for springtails to eat and poo out as GRSPs ideal for building aggregates using mineral from newly weathered up rocks. Their tap roots grew down, contributed to breaking up rock, prising new spaces for soil creatures, and providing support and resilience in dryer climes. These spaces provided a new environment for oribatids consuming degraded lignin making more poo to glue the soil particles together and build new deeper soil structures. The structured soil became more resilient to cold and warm, hot and dry. And the creatures ran round in the pores distributing the food, fungi, bacteria and minerals – from volcanic and weathered rock, so that the soil was more extensive and rich..
Lignin pellets
Carbon Cycle
Carbon Cycle
The ratio between the stable isotopes of carbon (12C/13C) indicate significant changes in the carbon cycle took place starting about ½ to 1 million years before the end of the Permian Period. This suggests a disrupted biological cycle. This may be due to large amounts of 12C trapped in Permian sediments, or to very low levels of dissolved oxygen
Quicker cycle
Quicker cycle
"As dominance shifted from lycopsids and pteridophytes in the Paleozoic, to gymnosperms in the Mesozoic, to angiosperms in the Tertiary, plant architecture became more sparing in its use of lignin. Lignin-degrading organisms were rare or absent in the Paleozoic, but diverse and abundant in the Tertiary. Thus the terrigenous organic-carbon cycle has quickened over time, the fraction of terrestrial primary production preserved in coals and kerogens has declined, and terrestrial production has been able to increase over time without concomitant rises in atmospheric O2. " (Robinson 1990)
There are hypotheses that the warming and drying in this period shifted the amount of carbon being fixed in the soil to being recycled into the atmosphere. Throughout the evolution of soils, there has been a balance of what happens to the carbon captured by plants. Depending on whether the particular decomposition process, some is emitted as carbon dioxide or methane, and some is captured in compounds in communities in the soil. The latter is now called 'carbon capture or 'sequestration' and is increasingly the focus of attention these days as a way of dealing with global warming, as we will see later.
By about 250 mya there were approximately 40 different families of land-dwelling vertebrates inhabiting the globe, relying on soil for survival.
But then something monumentally life-destroying happens.
The greatest extinction, called the End Permian Extinction occurs.
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