Ecology: Decomposers

• A decomposer is any organism breaking down or consuming decaying material.
• They range in complexity from bacteria to fungi.
• They recycle dead organisms back into the Earth.
• Decomposers help produce foods like bread using yeast.

Factors affecting Decomposition

• Temperature, oxygen, and water levels affect decomposition rates.
• Warm temperatures with high oxygen and water accelerate decomposition.
• Cold temperatures with low oxygen and water slow or halt decomposition.
• Decomposition is more common in warm climates like Mexico and Hawaii compared to polar regions like Alaska.
• Decomposers are heterotrophs, obtaining energy from other organisms.

Decomposers vs. Scavengers and Detritivores

• Scavengers eat dead organisms on a larger scale, aiding decomposition, vultures are an example.
• Detritivores are decomposers that further break down dead matter, earthworms are an example.

Examples of Decomposers

• Decomposers are widespread across most habitats.

Bacteria

• Bacteria are single-celled organisms found in various environments, including inside other organisms.
• Soil bacteria in the topsoil chemically break down organic material.
• Bacillus subtilis and Pseudomonas fluorescens are common soil bacteria involved in decomposition.
• Billions of bacteria can exist in a single gram of soil.

Earthworms

• Earthworms are invertebrates that consume dead organic material.
• Earthworms break down the material into smaller pieces and enrich the soil through excreted waste.
• Earthworm waste contains nutrients like nitrogen and phosphorus.

Fungi

• Fungi produce spores and feed on organic material.
• They release enzymes to break down organic material chemically.
• Fungi release nitrogen and phosphorus into the soil.
• Common fungi include mushrooms, molds, and yeast.

Insects

• Insects such as saprophages break down organic material
• Saprophages consume dead organisms and release waste into the soil.
• Carrion beetles, blowflies, and dung beetles are examples of saprophages.

Decomposers by Environment

• Oceans: bacteria, fungi, tube worms, echinoderms, crustaceans, mollusks
• Freshwater: mildew, yeast, water mold, trumpet snail
• Deserts: dung beetle, fly, Saharan silver ant, millipede
• Grasslands: turkey tail mushroom, termite, acidobacteria
• Mountains and Forests: millipede, mushroom, beetle, pillbug, slug, snails, bolete mushroom, purple fairy fingers, mountain pine bark beetle

Decomposers in Food Chains

• Decomposers recycle dead organisms, returning nutrients to the Earth.
• Producers then use these nutrients to make their own energy from the sun.

Stages of Decomposition

• Fragmentation: physical breakdown of dead matter by organisms.
• Leaching: water-soluble nutrients release from dead matter into surrounding soil.
• Catabolism: bacteria and fungi chemically break down matter.
• Humification: production of humus, a nutrient-rich dark soil, through digestion by organisms.
• Mineralization: further decomposition of humus, releasing inorganic nutrients like nitrogen and phosphorus into the soil.

Importance of Understanding Decomposition

• Understanding decomposition aids in creating biodegradable materials.
• Biodegradable plastics break down into simple compounds usable by the environment in weeks to months.

Decomposers recycle dead organisms, breaking down decaying material. Temperature, oxygen, and water levels affect decomposition rates. Scavengers eat dead organisms and detritivores further break down dead matter.