DrFever
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The soil ecosystem is tremendously varied - more-so than many above-ground plant and animal food webs. Each species has slightly different requirements. Aerobic microbes require oxygen. Anaerobes require the absence of oxygen. Some prefer either a high or a low pH, or high or low moisture. Many organisms can digest simple sugars, while only a few species have the enzymes to digest lignin, a major component of woody tissue.
At the microscopic level, soil conditions can change drastically from one point to the next, so a variety of organisms may be present in a single soil sample. Aerobes may live near anaerobes. Organisms requiring high pH may live near those preferring low pH.
Microbes differ greatly in how they get their energy. Most soil organisms are heterotrophs that get their energy and carbon from breaking down organic compounds. In contrast, the autotrophs use inorganic carbon (carbon dioxide). There are two groups of autotrophs. Phototrophs, such as plants and a few soil organisms, get their energy from light. Chemotrophs are a small, but important, group of soil bacteria that get their energy from oxidizing inorganic compounds including ammonium, nitrite, and sulfur compounds.
Macro-organisms, such as mites, beetles, and earthworms, are also tremendously varied in what they eat, their life cycle, and what agricultural conditions they will or will not tolerate. Each plays a different role in eating and breaking down plant residue and their fellow soil organisms.
At the microscopic level, soil conditions can change drastically from one point to the next, so a variety of organisms may be present in a single soil sample. Aerobes may live near anaerobes. Organisms requiring high pH may live near those preferring low pH.
Microbes differ greatly in how they get their energy. Most soil organisms are heterotrophs that get their energy and carbon from breaking down organic compounds. In contrast, the autotrophs use inorganic carbon (carbon dioxide). There are two groups of autotrophs. Phototrophs, such as plants and a few soil organisms, get their energy from light. Chemotrophs are a small, but important, group of soil bacteria that get their energy from oxidizing inorganic compounds including ammonium, nitrite, and sulfur compounds.
Macro-organisms, such as mites, beetles, and earthworms, are also tremendously varied in what they eat, their life cycle, and what agricultural conditions they will or will not tolerate. Each plays a different role in eating and breaking down plant residue and their fellow soil organisms.