Search results
Results from the WOW.Com Content Network
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 ...
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 ...
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 ...
Histosols are organic soils lacking permafrost within 100 cm of the surface; they are characteristically formed on wet sites, e.g. bogs, some fens and some muskeg areas. 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.
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.
Substances may be excreted to the surface of the plant or into intercellular cavities or canals. Some of the many substances contained in the secretions are not further utilized by the plant (resins, rubber, tannins, and various crystals), while others take part in the functions of the plant (enzymes and hormones).
The detailed study of reproductive structures in plants led to the discovery of the alternation of generations, found in all plants and most algae, by the German botanist Wilhelm Hofmeister. This discovery is one of the most important made in all of plant morphology, since it provides a common basis for understanding the life cycle of all plants.
A sapric is a subtype of a histosol [1] where virtually all of the organic material has undergone sufficient decomposition to prevent the identification of plant parts and even fecal matter. [ 2 ] [ 3 ] Muck is a sapric soil that is naturally waterlogged or is artificially drained.