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Soil ORGANISMS

Soil ORGANISMS. Global Soil Biodiversity Initiative. website. More useful way to classify soil organisms for our purposes:. MICROFAUNA : < 0.1 mm (WIDTH) Bacteria, fungi, nematodes MESOFAUNA : 0.1 – 2 mm Springtails, pseudoscorpions, dipluran MACROFAUNA : 2 – 20 mm

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Soil ORGANISMS

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  1. Soil ORGANISMS

  2. Global Soil Biodiversity Initiative • website

  3. More useful way to classify soil organisms for our purposes: • MICROFAUNA : < 0.1 mm (WIDTH) • Bacteria, fungi, nematodes • MESOFAUNA : 0.1 – 2 mm • Springtails, pseudoscorpions, dipluran • MACROFAUNA : 2 – 20 mm • Ants, some mites, earthworms, beetles • MEGAFAUNA : > 20 mm • Moles, reptiles, badgers

  4. Mesofauna and Macrofauna

  5. arthropods • ¾ of all living organisms • Exoskeleton, jointed legs, segmented body • Insects • Crustaceans • Arachnids • Myriapoda

  6. Shredders • Microbial taxis

  7. Mites arachnids

  8. Mite Facts • 4 pairs legs • Blind; use physical and chemical sensing to navigate • 40,000 described species • Variety of food preferences (microbes, plants, some carnivorous)

  9. Extracted from one ft2 of top two inches of forest litter and soil

  10. Very persistent • Withstand 100x as much radiation as humans • Persist in an area after it becomes industrialized • Therefore can be used to determine prior vegetation type • Fossilized mite assemblages are used to reconstruct past environments

  11. Springtails (Collembola) • Arthropods • Invertebrates with external skeleton • 6 legs • Spring or hop • Furca • Eat fungal hyphae, spores and detritus • Some predatory on mites • 40,000 / m3 topsoil

  12. Can withstand freezing conditions • Have been featured on a postage stamp!

  13. Proturans • Hexapods • No antennae, no eyes • Pale or yellowish, pointed at both ends • Found in leaf litter, humus, moss, decaying wood • 700 described species

  14. Raise their back end when disturbed (like scorpions) • Eat fungal hyphae, are eaten by mites, spiders pseudoscorpions

  15. Diplurans • White or colorless hexapods • Some are dark • Elongated body • Head has pair of strings with beaded segments • Confused with earwigs but have no eyes or wings • Can regenerate lost body parts

  16. Diplurans vs. Earwigs • Some have pincers • Diplurans are not insects • Earwigs have pincers • Earwigs are insects

  17. Live in leaf litter, wood, under rocks and logs • Eat decomposing plant and animal matter; some eat nematodes and small arthropods

  18. Pseudoscorpions • Arachnids • Fused head and thorax; 11-12 segments in abdomen • Smaller head appendages are for feeding; larger ones for defense • Molt; can live 3-4 yrs

  19. Live under bark, stones, in leaf litter, caves • Have appeared on a postage stamp!

  20. Carnivorous: eat larvae, ants, mites, flies

  21. Beetles Arthropods; order Coleoptera 370,000 described species (40% of all known insect species; 30% of all known animal species) Some omnivores, some eat plants, fungi, some are carnivores Larvae (grubs)

  22. Hardened forewings cover body of beetles • Most soil beetles are brown or black • Some soil beetles are wingless

  23. Rove beetle Largest beetle family in North America Very fast and agile, are biting Carnivorous; consume more than own weight in a day Act as good “pesticides” by eating harmful root maggot flies

  24. Rove beetles

  25. Featherwing beetles • Smallest known beetles • Wings are long and are feather-shaped • Abundant on forest floor

  26. Short-winged mold beetles • Eat mold, also springtails, mites, symphylans • Have beady antennae to use in the confining passages of soil • Have short wing covers that do not restrict movement

  27. Other Macrofauna (5%) and Mesofauna(3%) CHORDATES (vertebrates) mammals, amphibians, reptiles PLATYHELMINTHES (flatworms) ASCHELMINTHES (roundworms, nematodes) MOLLUSKS (snails, slugs) ARTHROPODS : (insects, crustaceans, arachnids, myriapoda)

  28. vertebrates • Squirrels, mice, groundhogs, rabbits, chipmunks, voles, moles, prairie dogs, gophers, snakes, lizards, etc. • Contribute dung and carcasses • Taxicabs for microbes

  29. nematodes

  30. NEMATODES

  31. NEMATODES Bacteria feeder Fungal feeder

  32. Predatory Nematode

  33. Root-feeding nematodes

  34. Nematode Trappers • Fungal hyphal rings constrict when a nematode swims through.

  35. Nonsegmented, blind roundworms • > 20,000 species • Eat bacteria or fungi or plants (stylet) • And protozoa, other nematodes, algae • Specialized mouthparts • Can sense temperature and chemical changes

  36. nematode

  37. Feeding Habits Carnivores : parasites and predators Phytophages: eat above ground green plant parts, roots, woody parts Saprophages: eat dead and decaying OM Microphytic feeders: eat spores, hyphae, lichens, algae, bacteria

  38. Movement existing pore spaces, excavate cavities, transfer material to surface improve drainage, aeration, structure, fertility, granulation

  39. The divisions of the 5%: 40% bacteria and actinomycetes

  40. BACTERIA

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