As much is going on below ground as above. Imagine taking a
Most of the creatures are small - just beyond our eye sight. They are like specs. They have to move round either by burrowing or using pores and some other creatures tunnels. In terms of total weight or biomass, worms equal all the 'mesofauna together; it just there are lots more of the latter smaller creatures....
On the Surface ..
Active non-burrowing worms consume decaying plant residues on the soil surface, They are like the ones in wormeries – specifically red manure earthworms, belonging to a group called epigeic.
Sinodenron cylindricum roam over the soil surface looking for quite large prey - slugs & snails, cricket nymphs, insect larvae and isopods like woodlice, and even centipedes). Having lots of ground beetles around is a good indicator of healthy soil. They need lots of other creatures to live. From Royal Entomological Society "As the name suggests, many ground beetles spend their time on the ground and few can fly. The fusion of their wing cases (elytra) acts as protecting armour. Both larvae and adults are carnivorous and often specialise in eating slugs and snails, as well as eating a range of carrion. Depending on the ground beetle species, they will also attack aphids and other pest insects. Many ground beetles eat by vomiting on their prey and waiting for their digestive enzymes to make their food more fluid and easier to eat. By encouraging them into your garden you can start on the road to a natural method of pest control. Many ground beetles are nocturnal and need some form of shade during the day. Provide them with shelter such as a log pile, leaf litter or just some large stones...
See 'Beetles' for more
shred plants whereas centipedes are carnivores, crawling through worm holes looking for smaller creatures like ants
Ants in turn feed on oribatid mites(see grazing - more about these mites below)...
Just below the surface ..
3 groups..Is the body long with distinct segments? (if 'yes' go to 2). If 'No'..
Dicrytomidae and Arrhopalitidae. These round bodied (dynamically good for holding water) springtails are often near the surface and some live on the surface in vegetation, like grass.
Soil invertebrates influence microbial populations, and hence indirectly affect total metabolism, by 1. Regulating fungal growth (Warnock et al., 1982; Ulber, 1983; Gochenaur, 1987),
2. Disseminating fungal and bacterial propagules into new substrates (Visser et al., 1981) or
3. Reactivating senescent microbial colonies (Hanlon, 1981).
Folsomia (F.candida) are currently used in laboratory tests for the early detection of soil pollution. Acute and chronic toxicity tests have been performed by researchers, mostly using the parthenogenetic isotomid Folsomia candida.[look at source]
ISO Standard for evaluating toxicity to F.candida in lab conditions, as way to determine soil quality
Plant material, mainly from moss, bracken, pine needles and bark is consumed by enchytraeid and lumbricid worms, sciarid larvae (young fungus gnats) and phthiracarid mites (primitive oribatids). Fungal material (+ or - plant material) is ingested by all groups, like camisiid and oppiid mites, some species of Collembola, sciarid and chironomid larvae
Isotomid springtails and chironomid larvae (adult flies for fishing)consume faecal material like this from oribatids... Oribatid faecal pellets inside pine needle
More on soil animals diets
The endogeic earthworms, like L. rubella, pull leaves down into burrows. In soil fauna terms they are like massive earth moving equipment. Earthworm eating plant stem Worms working a field, then themselves
The ones that live deep down belong to the group Anecic, the most famous of which is the earthworm Lumbricus terrestris
Insect larvae. They are mainly white coloured with many segments and usually a dark head. Like this vine weevil larvae (white brown head), with pupae nearby kicking legs and hatching into adult insect.
When leaves fall..
with virtually no distinguishing features. So much so they weren't discovered till the 20th century. they feed on organic matter released by decay. They are considered the earliest 6-legged creatures to evolve.
Mites (Key for Mites)
Worms mangle organic matter but it is the myriad of mites that break down organic matter into v small parcels for fungi and bacteria to act on. The 'mesofauna' break down the leaves – springtails prising apart leaves. But mainly oribatids
Another group of mites – Mesostigmata.have a long proboscis to
None of the main soil creatures are 'bugs' in the proper sense of the word - ie belonging to the Order Hemiptera of Insects (like aphids and cicadas). In fact very few insects spend their whole lives underground. This is possibly because insects evolved after mites and springtails, by which time time the soil was pretty well colonised. The key element of classification among insects is their wings. So Hemiptera refers to 'half' (Hemi) wings (Ptera). However wings are no use underground. So did they evolve from other soil arthropods and take flight? Springtails would be most likely ancestors. (New light on oldest insect)
The third main group of soil mesofauna, alongside springtails and mites, are nematode worms. Pretty boring looking - basically just a sheath covering the guts
Protozoa and smallest of all and most numerous.
Bacteria are tiny, one-celled organisms about (1 µm). A teaspoon of decent soil 100 million - 1 billion bacteria. That is as much mass as two cows per acre. – a tonne.
Nitrogen fixing bacteria also live closely with roots. The bacteria invade root hairs and multiply making the nodules (below), where the bacteria convert free nitrogen into nitrates which is like a natural fertiliser for the plant.