nyc compost project: science 5--physical decomposers


nematodes	mite

Besides the many types of bacteria and fungi, a multitude of larger organisms add diversity to the compost pile. Many of them feed on dead bacteria and their by-products as well as each other. The following is just a sampling of some of the more common organisms in this diverse group of physical decomposers:

Nematodes, or roundworms, are the most abundant invertebrates in the soil. Typically less than one millimeter in length, they prey on bacteria, protozoa, fungal spores, and each other. Though there are pest forms of nematodes, most of those found in soil and compost are beneficial.

Fermentation mites, also called mold mites, are transparent-bodied creatures that feed primarily on yeast in fermenting masses or organic debris. Literally thousands of these individuals can develop into a seething mass over a fermenting surface. As a result, they often become pest species in fermenting industries, such as wineries and cheese factories. They are not pests in the compost pile.


springtail	sow bug

Springtails, or collembula, along with nematodes and mites, dominate in numbers among the soil invertebrates. They are a major factor in controlling fungi populations. They feed principally on fungi, but also on nematodes and small bits of organic detritus.

Wolf spiders are truly "wolves" of the soil and compost communities. They don't build webs, but run freely, hunting their prey. Depending on the size of the spider, their prey can include all sizes of arthropods— invertebrate animals with jointed legs and segmented bodies.

Centipedes are frequently found in soil and in compost communities. They prey on almost any type of soil invertebrate near their size or slightly larger.

Sow bugs feed on rotting woody materials and highly durable leaf tissues, such as the veins comprised of woody xylem tubes. Sow bugs that roll up like an armadillo are known as pill bugs or roly-polys.

redworm

Ground beetles have many representatives lurking through litter and soil spaces. Most of them feed on other organisms, but some feed on seeds and other vegetable matter.

Redworms play an important part in the break-down of organic materials and in forming finished compost. As worms process organic materials, they coat the material with a mucus film that binds small particles together into stable aggregates and helps to protect nutrients from being leached out by rain. These stable aggregates give soil a loose and well-draining structure.

compost science 1: organics in new york city’s residential waste stream
compost science 2: the decomposition process
compost science 3: how does compost happen?
compost science 4: chemical decomposers—microorganisms
compost science 5: physical decomposers—larger organisms

nyc compost project | how to compost | compost science | nyc compost resources
sitemap