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Soil life, soil biota, soil fauna, or edaphon is a collective term that encompasses all organisms that spend a significant portion of their life cycle within a soil profile, or at the soil-litter interface. These organisms include earthworms, nematodes, protozoa, fungi, bacteria, different arthropods, as well as some reptiles (such as snakes ...
Soil mesofauna do not have the ability to reshape the soil and, therefore, are forced to use the existing pore space in soil, cavities, or channels for locomotion. Soil Macrofauna, earthworms, termites, ants, and some insect larvae, can make the pore spaces and hence can change the soil porosity, [5] one aspect of soil morphology. Mesofauna ...
Bacteria and Archaea, the smallest organisms in soil apart from viruses, are prokaryotic. They are the most abundant microorganisms in the soil, and serve many important purposes, including nitrogen fixation. [9] Some bacteria can colonize minerals in the soil and help influence weathering and the breaking down of these minerals.
A diazotroph is a microorganism that is able to grow without external sources of fixed nitrogen. Examples of organisms that do this are rhizobia and Frankia and Azospirillum. All diazotrophs contain iron-molybdenum or iron-vanadium nitrogenase systems. Two of the most studied systems are those of Klebsiella pneumoniae and Azotobacter vinelandii ...
Microorganisms like those that make up biological soil crust are good at responding quickly to changes in the environment even after a period of dormancy such as precipitation. Desiccation can lead to oxidation and the destruction of nutrients, amino acids, and cell membranes in the microorganisms that make up biological soil crust. [16]
Soil erosion occurs naturally, but human activities can greatly increase its severity. [28] Soil that is healthy is fertile and productive. [29] But soil erosion leads to a loss of topsoil, organic matter, and nutrients; it breaks down soil structure and decreases water storage capacity, reducing fertility and water availability to plant roots.
As these organisms eat, grow, and move through the soil, they make it possible to have clean water, clean air, healthy plants, and moderated water flow. There are many ways that the soil food web is an integral part of landscape processes.
Soil is the most speciose (species-rich) ecosystem on Earth, but the vast majority of organisms in soil are microbes, a great many of which have not been described. [ 71 ] [ 72 ] There may be a population limit of around one billion cells per gram of soil, but estimates of the number of species vary widely from 50,000 per gram to over a million ...