Forest Soils & Site Productivity

1. Forest Soils & Site Productivity Soil Organic Matter and Organisms 1

2. ESRM 410: Forest Soils and Site Productivity The Role of Soil Invertebrates (Far Side creator-Gary Larson) 2 (some of the following slides contributed by J Marra-WA Dept of Agric)

3. Heterotrophic Respiration(Energy Flow)Deciduous Forest Invertebrates 10% Decomposers 95% Microbes Bacteria & Fungi 90% Net PrimaryProduction Herbivores 5% (Richle 1981) (Chemoheterotrophs) Now much research is focused on regulation of nutrient cycling as well as ‘energy flows’ thus revealing organism/environment interaction! 3

4. Site and SoilProductivity Microbial / Invertebrate Interactions in Soil Comminution- increases surface to volume ratios of litter Innoculation - transport microbial propagules to new substrates Grazing - pruning response increases fungal metabolism - releases nutrients contained in microbial biomass - alters competitive interactions and species composition Mutualism - coevolved interaction in which both microbes and invertebrates benefit 4

5. Major groups of Soil Fauna The Microfauna < 0.1 mm Nematodes or roundworms Protozoa 5

6. Major groups of Soil Fauna The Mesofauna 0.1 - 2 mm Mites Featherwing beetle Springtails Protura Pseudoscorpions Diplura 6

7. Major groups of Soil Fauna The Macrofauna > 2 mm Earthworms Millipedes Ants Termites Ground beetles Isopods 7

8. Invertebrate Effects on Soil Productivity The Earthmovers!! Earthworms Ants Termites 8

9. Earthworms - earthworms + earthworms 9

10. Termites: Termitidae Queen Workers and Soldiers 10

11. Termite mound Fungus farming Termitidae 11

12. Productivity and soil properties in relation to distance to termite mounds. Distance NPP Infiltration rate Moisture Bulk Density to mound (m) (g m-2 yr-1) (cm h-1) (%) (g cm-3) 1-3 728 12.0 29.2 1.28 26-28 280 8.0 20.5 1.39 (Arshad 1982) 12

13. Leaf Cutter Ants: Atta sp. 13

14. Leaf-cutter Ant Trail Photos by Bob Gara 14

15. Leaf cutter Ant Defoliation of Pine 15

16. Excavated fungus garden 16 Vertical distribution of colony

17. Naphthalene Untreated North Carolina Puerto Rico Percent mass remaining Costa Rica Litterbag Study Comparison of Tropical and Temperate Forests (Heneghan et al. 2000) 17

18. Birch Seedling Growth (Setala and Huhta1991) leaves stems roots in humus roots in mineral soil C - without invertebrates F - with invertebrates 18

19. Invertebrates contribute to soil productivity by: ► regulating decomposition and nutrient mineralization processes ► stimulate the activity of microbial organisms, ► altering physical properties such as soil structure and porosity ► increase moisture holding capacity of soil. Their effects are generally greater in tropical ecosystems than temperate because of the more moderate climate. Their effects are generally greater in deciduous forests than coniferous because of higher substrate quality. 19

20. Effects of insects and diseases on forest productivity Good or bad? (some of the following slides from Bob Edmonds) 20

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22. Mountain pine beetle attacks of lodgepole pine in BC.  These pictures were taken east of Quesnel about 25 miles last summer (2005).  22

23. SUDDEN OAK DEATH An introduced disease? caused by Phytophthora ramorum The current host list includes: California black oak, coast live oak, Shreve oak, tanoak, rhododendron, California bay laurel, big leaf maple, madrone, manzanita, huckleberry, California honeysuckle, toyon, California buckeye, California coffeeberry, Douglas-fir and coast redwood and Arrow wood (in Germany, the United Kingdom, and the Netherlands). 23

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26. Mean Cumulative Height Growth (inches) Note height growth reduction in infected Douglas-fir trees over 14 year period. Trees were age 24 at beginning of study 26

27. Impact of diseases and insects – good or bad a. Mortality b. Reduced growth c. Destruction of merchantable wood (decay) d. Reduction in pulp yield e. Reduced wood quality - stain f. Delayed regeneration; inadequate stocking (trees/acre) g. Site deterioration - build up of pathogens h. Changes in species succession i. Creation of biodiversity j. Decomposition and nutrient cycling 27

28. Management affects soil organisms • We know that land management practices change the soil community. The link between specific changes and soil function is less clear. • Logging and Farming can reduce organic matter in the soil • Reducing tillage tends to result in increased growth of fungi, including mycorrhizal fungi. • Decrease in OM may decrease nutrients, CEC, porosity and water infiltration, ??? • Fire may also decrease OM, affect soil organisms, etc (direct, indirect, long & short term) 28

29. Management affects soil organisms • Soil biological crusts are very sensitive to trampling. • Biosolids – OM, nutrients, water, … • Soil compaction, lack of vegetation, or lack of plant litter covering the soil surface tends to reduce the number of soil arthropods, fungi, bacteria, etc as well as affecting root growth, aeration and water infiltration (EROSION!). 29

30. Site and SoilProductivity Physical and Chemical Properties Biological Properties •soil organic matter • soil moisture balance • soil structure and porosity • nutrient availability • soil volume • microclimates •mycorrhizas • nitrogen fixation • microbial decomposition • invertebrate regulation 30

31. A well managed soil is a Good Soil • A GOOD SOIL is a LIVE SOIL • A LIVE SOIL is a Resilient Soil 31