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Aridisols (from the Latin aridus, for "dry", and solum) form in an arid or semi-arid climate. Aridisols dominate the deserts and xeric shrublands, which occupy about one-third of the Earth's land surface. Aridisols have a very low concentration of organic matter, reflecting the paucity of vegetative production on these dry soils. Water ...
Most Histosols occur in Canada, Scandinavia, the West Siberian Plain, Sumatra, Borneo and New Guinea. Smaller areas are found in other parts of Europe, the Russian Far East (chiefly in Khabarovsk Krai and Amur Oblast), Florida and other areas of permanent swampland. Fossil Histosols are known from the earliest extensive land vegetation in the ...
The Termitichnus ichnofacies, which included a large array of termite nests and pellets, is found in Oligocene Alfisols, Aridisols, and Oxisols. All the tetrapod bones and tracks from the paleosol sequences of Late Devonian and Mississippian of New York and Pennsylvania, U.S.A. are found in Aridisols and Alfisols. The Alfisols in the Texas High ...
However, the definitions are different. Some Histosols (WRB) belong to the Andisols (ST), and some Andosols (WRB) belong to the Inceptisols (ST). Andosols typically develop in parent materials containing high proportions of glass. If significant amounts of glasses are still present, they show vitric properties and receive the Vitric qualifier.
Some Histosols have been drained, especially to permit cultivation. In the US, Mollisols occur mostly on the Great Plains, and in some areas of the west. There is a considerable variety of Mollisols, including soils very closely resembling the Chernozem ("black earth") of eastern Europe (parts of Russia, Ukraine and neighboring regions), and ...
Genetic fragments such as pseudogenes, regions of DNA that are orthologous to a gene in a related organism, but are no longer active and appear to be undergoing a steady process of degeneration from cumulative mutations support common descent alongside the universal biochemical organization and molecular variance patterns found in all organisms ...
In DNA double helix, the two strands of DNA are held together by hydrogen bonds. The nucleotides on one strand base pairs with the nucleotide on the other strand. The secondary structure is responsible for the shape that the nucleic acid assumes. The bases in the DNA are classified as purines and pyrimidines. The purines are adenine and guanine ...
Many aridisols have well-developed Bt horizons showing clay movement from past periods of greater moisture. Entisol – recently formed soils that lack well-developed horizons. Commonly found on unconsolidated river and beach sediments of sand and clay or volcanic ash, some have an A horizon on top of bedrock. They are 18% of soils worldwide.