If you have been keeping a compost pile, you have been maintaining an active ecosystem that is based on the breakdown of the organic materials that you are composting. With optimal conditions, your compost pile should have all the components of an active ecosystem. All healthy ecosystems consist of energy source, primary consumers and multiple levels of secondary or tertiary consumers that form a healthy food web.

The base of the compost ecosystem is your compost, and the primary consumers are the organisms that feed on the compost, decomposing it into soil. Primary consumers include bacteria, fungi, actinomysetes and nematodes. These are the microscopic decomposers. Decomposers that you might see are mites, earthworms, beetle larvae, millipedes, sowbugs, snails, slugs and whiteworms. It is important to maintain the right habitat for the decomposers to work your compost pile. Here, you need to ensure that the pile is kept sufficiently moist, but without standing water. Creating a higher temperature in your compost pile, 120-160 degrees Fahrenheit, will speed up the life cycles of the decomposers and the breakdown of your compost into soil.

The size and abundance of secondary consumers can be used to estimate the health of your compost pile. A healthy compost pile will have more secondary consumers because there is more prey from primary consumers for the secondary consumers to consume. Secondary and tertiary consumers include carabid beetles, rove beetles, earwigs, other beetles, ants, mites, spiders, pseudoscorpions, centipedes, springtails, soil flatworms, nematodes, protozoa and rotifera.

While a healthy compost pile ecosystem will help break down the compost into beautiful soil, compost can create a source habitat for garden pests or annoying insects that can ruin your barbeque. Place your compost pile away from garden, patio or picnic areas to prevent issues with flies, ants, sowbugs and snails. Fruit flies and houseflies can increase with too much fresh fruit or vegetable waste, so add these to the compost pile slowly over time or after a hard freeze. Placing the pile way from the garden will reduce the sowbugs and snails that can move from your compost to your vegetables. Scarab beetle larvae can invade lawns and vegetables, so look for large C-shaped beetle larvae in your pile.

For an opportunity to learn more about decomposer and pest insects, pollinator and beneficial insects, composting and more, check out our “Grow Your Own, Nevada!” program. 

Newton, J. and Andrews, A. 2016, The Ecosystem of Compost Piles, Reno Gazette-Journal

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