1 / 34

THE LIVING SOIL

THE LIVING SOIL. Functions of soil. Support plant growth Regulate water flow Absorb and transform pollutants Habitat for living organisms  Soil Quality. Objective :. Soil organisms: Who are they and what do they do? How do they contribute to soil quality?. VEGETATION.

saddam
Download Presentation

THE LIVING SOIL

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. THELIVINGSOIL

  2. Functions of soil • Support plant growth • Regulate water flow • Absorb and transform pollutants • Habitat for living organisms  Soil Quality

  3. Objective: Soil organisms: • Who are they and what do they do? • How do they contribute to soil quality?

  4. VEGETATION • Vegetation - Additon of Organic Matter (OM). • Prairie ~ OM added to upper 2 ft. of soil due to fibrous root system of grass plants. Ap A AB Bg

  5. VEGETATION • Forest ~ OM added to upper 4 “ due to yearly leaf fall to surface of soil. A

  6. Prairie - Border Biotic Factor • Prairie - Border soils (oak savannahs) have the influence of the prairie and forest ~ due to changes in vegetation over the past 8000 years the soils have been both under prairie and forest.

  7. Soil Organisms: sizes and abundances

  8. Size classification of soil fauna • Microfauna (<0.1mm diameter) • Occupy water films and existing water-filled pores • Protozoa, nematodes

  9. Mesofauna (0.1 – 2mm diameter) • Occupy existing water- and air-filled pore spaces • Able to break free from surface tension of soil water • Potworms, microarthropods

  10. Macrofauna (2-20mm diameter) • Able to alter soil structure • Earthworms, macroarthropods

  11. Bacteria • Microscopic, single-celled • Up to 3 billion/g • Autotrophs, decomposers, plant symbionts, pathogens

  12. Fungi • Thread-like hyphae; some form visible fruiting bodies (mushrooms, bracket fungi) • Up to 50 meters/g • Decomposers, plant symbionts, pathogens, predators

  13. Protozoa • Single-celled animals • 10,000 - 100,000/g • Feed on bacteria, fungi, decaying organic matter, other protozoa

  14. Nematodes • 1 - 4.5 mm • Up to 7 million /m2 • Bacteria feeders, fungus feeders, predators, plant roots, parasites

  15. Isopods • Crustaceans • Feed on decaying plant residues

  16. Myriapods • Centipedes – predators • Millipedes – decaying plant residues • Symphylans, pauropods

  17. Springtails • 1 - 7 mm • Up to 100,000/m2 • Fungus feeders, decaying OM, some plant feeders

  18. Mites • 0.1 - 3mm • Up to 250,000/m2 • Decomposers, predators, parasites, plant feeders

  19. Earthworms • 2 - 20 cm • 10 - 950/m2 • Many introduced species • Decaying organic matter • Different ecological types

  20. Anecic Earthworms • Medium to large size • Dorsal, anterior pigment • Permanent vertical burrows • Forage for plant residues on the soil surface • e.g. Lumbricus terrestris

  21. Endogeic Earthworms • Small to medium size • Unpigmented • Horizontal burrows in topsoil • Feed on dead plant roots and other buried organic matter • e.g. Octolasion tyrtaeum

  22. Epigeic Earthworms • Small in size • Red-brown pigment • Weak burrowers; do not inhabit mineral soils • Forest litter, compost • e.g. Eisenia fetida

  23. Role in Soil Processes • Soil formation and soil structuring • Nutrient recycling and retention • Population regulation

  24. Role in Soil Formation • Fragment and humify organic residues and mix into mineral soil

  25. Soil formation • Formation and stabilization of aggregates • Formation of pore spaces

  26. Nutrient Availability • Symbiotic associations • Rhizobium and legumes • Mycorrhizae and most plants

  27. Nutrient Availability • Nutrient mineralization from organic matter pools • Biological nutrient pool

  28. Population regulation

More Related