Soil Biology

Transcript

1. EES 140: Soil Science Kaizad F. Patel 1 EES 140 Spring 2017 Kaizad F. Patel Additional resources: Global Soil Biodiversity Atlas 2 “All life depends upon the soil... There can be no life without soil and no soil without life.” Charles E. Kellogg USDA Yearbook of Agriculture, 1938
2. EES 140: Soil Science Kaizad F. Patel 2 Classification Plants Earthworms Algae, lichens Bacteria Fungi Mycorrhizae Importance 3 4 Petrichor blood of the gods stone Actinomycetes (bacteria) Geosmin
3. EES 140: Soil Science Kaizad F. Patel 3 5 Streptomycin Isolated from Streptomyces sp. in soil Selman Waksman and Albert Schatz (Rutgers University) Selman Waksman: the only soil scientist to win the Nobel Prize Antibiotics 6 Antidepressants Mycobacterium vaccae
4. EES 140: Soil Science Kaizad F. Patel 4 7 8 More microbes in a teaspoonful of soil than people on the earth
5. EES 140: Soil Science Kaizad F. Patel 5 Aerobes: need O2 Facultative anaerobes: adapt to O2 conditions (Obligate) Anaerobes: sensitive to O2 Oxygen utilization 9 10
6. EES 140: Soil Science Kaizad F. Patel 6 11 Trophic types: Carbon source Heterotrophs organic compounds Autotrophs CO2 or carbonates Phototrophs Solar energy 12 Trophic types: Energy source Chemotrophs Inorganic compounds (N, S, Fe)
7. EES 140: Soil Science Kaizad F. Patel 7 13 Chemoautotrophic anaerobes Sulfur reducing bacteria energy from sulfate reduction Methanogenic bacteria Energy from reduction of CO2 Orono Bog Walk Grand Prismatic Spring, Yellowstone National Park Macrofauna Mesofauna Microfauna Increasing size Increasing # of individuals per cm3 soil 14 Size moles, prairie dogs, earthworms springtails, mites nematodes – flora
8. EES 140: Soil Science Kaizad F. Patel 8 15 Macrofauna Mole Earthworm Millipede 16 Mesofauna Springtail Mite
9. EES 140: Soil Science Kaizad F. Patel 9 17 Microfauna Nematodes 18 Microflora
10. EES 140: Soil Science Kaizad F. Patel 10 19 Species diversity vs. Functional diversity Organism 1 Organism 2 (host) Example Symbiosis (mutualism) Benefits Benefits Mycorrhizae; Lichens Commensalism benefits Unaffected Basidiomycetes and bacteria Parasitism Benefits (parasite) Adversely affected Parasitic nematodes and plants 20
11. EES 140: Soil Science Kaizad F. Patel 11 21 Physical weathering and pedoturbation Reduce soil moisture Soil structure, aggregates Exudates: attract microbes SOM input (decomposition) 22
12. EES 140: Soil Science Kaizad F. Patel 12 23 The rhizosphere The zone of soil immediately adjacent to plant roots 24 The rhizosphere The rhizosphere differs from the bulk soil 1. Acidity 2. Nutrient availability 3. Gas exchange 4. Organic exudates allelopathy mucilage 5. Microbes abundance activity
13. EES 140: Soil Science Kaizad F. Patel 13 non-native Pedoturbation, redistribution of soil Break down OM for further digestion by soil microbes 25 Additional facts 90 – 1500 pounds of biomass earthworms per acre of soil Can ingest 22 – 450 tons of soil per acre in a year 26
14. EES 140: Soil Science Kaizad F. Patel 14 Moist Sufficient soil organic matter Moderate to high calcium levels pH of 5.5 – 8.5 Low Salinity 27 28 Earthworm casts
15. EES 140: Soil Science Kaizad F. Patel 15 29 Photoautotrophs Convert inorganic C to organic N fixation Soil aggregation 30
16. EES 140: Soil Science Kaizad F. Patel 16 Hyphae Mycelia 31 Non-filamentous Filamentous Yeast Mucor Mushrooms OM decomposition: complex biomolecules Soil aggregation Glomalin Antibiotics 32
17. EES 140: Soil Science Kaizad F. Patel 17 Symbiosis Fungi + algae 33 Photosynthesis (carbohydrates) Protection Anchor the organism Provide nutrients and moisture Weathering of rocks “Pioneer species” 34
18. EES 140: Soil Science Kaizad F. Patel 18 Small (4-5 µ), single-celled OM decomposition anaerobic and facultative populations autotrophs and heterotrophs Important in N transformations 35 “blue-green algae” N fixation Cyanobacteria 36 Chlorophyll = photosynthesis Terraforming
19. EES 140: Soil Science Kaizad F. Patel 19 Symbiotic association with roots (nodules) e.g. Nostoc Anabaena Rhizobium 37 Cyanobacteria and N fixation 38 The Nitrogen Cycle Organic N e.g. amino acids Microbial biomass N mineralization ATMOSPHERE SOIL PLANTS ammonium nitrate inorganic forms of N N2 inert N-fixation ammonia immobilization leaching, loss to streams Nitrous oxide greenhouse gas nitrification denitrification decomposition uptake
20. EES 140: Soil Science Kaizad F. Patel 20 Atmospheric nitrogen (N2 ) ammonia organic N ammonium nitrate ammonification immobilization nitrification Nostoc Anabaena Rhizobium Nitrosomonas Nitrobacter 39 Filamentous bacteria OM decomposition: complex compounds Synthesize antibiotics e.g. Actinomycin, Streptomycin Petrichor Actinomycetes 40
21. EES 140: Soil Science Kaizad F. Patel 21 41 Actinomycetes and N fixation Symbiosis: Frankia nodules on the roots of red alder trees. Symbiosis between root and fungus Fungus gets sugars directly from roots Fungus increases nutrient acquisition. Fungus produces antibiotics, protects the plant Mycorrhizae stabilize soil structure. 42 fungus root
22. EES 140: Soil Science Kaizad F. Patel 22 43 Mycorrhizae extend from roots Greater access to nutrients Greater surface area = greater uptake of nutrients 44 Endomycorrhizae and Ectomycorrhizae
23. EES 140: Soil Science Kaizad F. Patel 23 45 Ectomycorrhizae Hartig nets 46 Arbuscular (endo) mycorrhizae Arbuscules branched, tree-like structures
24. EES 140: Soil Science Kaizad F. Patel 24 OM Oxygen Moisture Temperature Exchangeable cations, pH 47 Preferred pH of microbe groups Bacteria 6 to 8 Actinomycetes 7 to 7.5 Fungi 4 to 8 Predominant at low pH “extremophiles” Q10 temperature coefficient 48 Effect of snowpack Soil under snowpack Soil with snowpack removed Air Data from Tatariw and Patel, at the Dwight DeMerritt Forest
25. EES 140: Soil Science Kaizad F. Patel 25 49 Effect of snowpack Soil under snowpack Vernal transition Air Snow melts Meltwater available in spring Soil with snowpack removed What happens if there is no/less snow accumulation? 50 Burlese Funnel (macro and meso)
26. EES 140: Soil Science Kaizad F. Patel 26 51 Culture Techniques 52 Physiological measurements Soil respiration measurement Image: Holland Havercamp
27. EES 140: Soil Science Kaizad F. Patel 27 53 Genomic Techniques Soil Biology 54 Six ways soil biodiversity sustains us (web link)