Earthworms may lack the charm or excitement of more familiar animals, but their contribution to our world is significant. These ‘lowly creatures’ play a vital part within the natural soil ecosystem. They are also valued for their contribution to ecosystem services – ecosystem functions that are of direct benefit to humans through their action on soil processes.
Earthworm
Earthworms influence (and benefit) the soil ecosystem in a number of ways:
Recycling organic material: Earthworms, along with bacteria and fungi, decompose organic material. Most people know about earthworms and compost, but earthworms do the same in pasture soils, decomposing dung and plant litter and processing 2–20 tons of organic matter per hectare each year, and recycling leaf litter under orchards and in other forested areas.
Increasing nutrient availability: This happens in two ways: by incorporating organic materials into the soil and by unlocking the nutrients held within dead organisms and plant matter. Nutrients like phosphorus and nitrogen become more readily available to plants after digestion by earthworms and being excreted in earthworm casts.
Improving soil structure: Earthworm burrows alter the physical structure of the soil. They open up small spaces, known as pores, within the soil. When earthworms are introduced to soils devoid of them, their burrowing can lead to increases in water infiltration rates of up to 10 times the original amount.
Reduces carbon: Earthworms convert digestible carbon to a form that stays in the soil, trapping carbon dioxide in soil for an overall decrease in emissions1. Scientists in the US and China discovered that worms, though they release carbon dioxide from the soil into the air, actually capture (sequester) more CO2 than they release.
Providing food for predators: Earthworms, like all creatures, are part of food webs. Birds are well known predators, but native earthworms are also food for endangered and endemic land snails. This is another great use of technology on our planet. Bob Larson is a technologist and Marketing Director for 50 Plus!