THE DECOMPOSER FOOD WEB

As you probe deep into a forest litter layer, the leaves become increasingly moist and flimsy. Many have tiny holes in the blade and along the edges. These holes, made by minute insects and mites, allow fungi and bacteria to enter the interior of the leaf and represent the initial stages of decomposition.

For at the base of the litter-soil food chain are the bacteria and fungi. They get up to 80 to 90% of the energy available in the fallen debris. The 10 to 20% left is eaten by soil animals.

Many different animals inhabit the soil, ranging from moles to tiny insects. The soil-animal community depends on fallen debris from the forest canopy. Dried leaves and twigs, diseased stumps, decomposing logs, and animal remains make up the food base for protozoa, roundworms, earthworms, potworms, millipede, isopods, and many others. Some, like the diminutive mites and springtails occur in immense numbers.

There is a remarkable diversity of animal life that make up the decomposer food chain, including;

Slugs and snails feed on decomposing leaf litter and animal carcasses as well as living vegetation.

Earthworms prefer leaves with high nitrogen and sugar levels like maple, alder, ash, sycamore, and birch; less appetizing are the oaks and beech. See notebook.

Isopods also called wood lice or pillbugs; feed on decaying vegetation, carrion, and animal feces

Millipedes feed on dead leaves and decaying wood. When threatened, they curl up into tight ball.

Ants occupy several ecological roles. There are many species of ants in fields and forest; some are predators, some scavengers, some nectar-feeders. When ants take decomposing vegetation below ground into their burrows, they help recycle this material directly to the soil. Their burrowing activities also contribute to aeration of the soil.

Termites are among the only animals capable of eating and digesting wood. They feed on decaying trees, fallen logs, and unfortunately houses. Like ants, they are social insects, living in huge colonies. Termites have a unique association with certain single-celled protozoa that inhabit their guts. The protozoa, most of which have numerous long, whiplike flagella, actually digest the cellulose eaten by the termite.

Harvestman (Daddy Longlegs): Feed on decaying vegetation, as well as plant juices, and small insects. See notebook

Springtails are some of the most numerous and important animals in the decomposer food web. They have a unique abdominal structure which permits them to “spring” or jump suddenly. They are considered very primitive creatures. They ingest bacteria that enable them to digest plant material, in a relationship similar to termites.

Soil mites, like springtails, occur in soil in immense numbers. While they feed on some decomposing material, they eat mostly fungi, and can reduce fungal populations significantly.