1. Stinchfield Woods: Oak-Hickory Ecosystem

2. Introduction ► Located in southeastern MI ► Site characterized by ice-contact landform (steep kames and eskers), till with high coarse fragment concentration ► Highly variable soil formation linked to microsite conditions; alfisols (dark A, developed E, B t ) at low points, entisols (A, little/no E, subtle B) on upper slopes

3. Intro, cont. ► Overstory dominated by Carya glabra, C. ovata, Quercus rubra, Q. velutina, with some mesic indicators on lower slopes. ► Given variability of individual soil pits, will we see the basic trends continue through laboratory soil analyses? ► Research and presentation divided into three categories: physical, chemical, and biological properties of OH soil.

4. Physical properties presented by Amy of Team De La Solum

5. Physical Properties of Soil Pit Slope Aspect & Location % Coarse Fragments Soil Texture (assigned in field) Available Water Content (cm 3 water/cm 3 soil) Bulk Density (Mg/m 3 ) 1 SW Top-slope A 1%, B 20%, C 30%Loamy Sand0.061.19 2 NW Top-slope N/A Sandy Loam0.251.0305 3 North Mid-slope A 10%, E 15%, Bt 80%, C 85% Loam0.231.16 4 SE Mid-slope A 20%, E 30%, Bt 40%, B 50%, C 95% Loam/ Sandy Loam 0.491.43 5 NE Mid-slope A 1%, E 5%, Bt 10%, C 25% Sandy Loam0.280.86 Field Observations and Lab Calculations presented by Amy Ring De La Solum presented by Amy Ring of team De La Solum

6. Soil Profile Field Observations

7. Connecting Physical Properties to Soil Genesis ► Parent Material, Topography, and Climate:   Soil Formation Factors Influencing Soil Texture ► Soil Texture:   Impact on Bulk Density and Available Water Content

8. Chemical properties presented by Brian of Duripan Duripan

9. Across Ecosystems Stinchfield Woods is predominantly Sandy Loam (15-20% clay)

10. Across Ecosystems, cont.

11. Linkages ► CEC influenced by clay content, organic matter, and declines with acidification. ► Base saturation buffers against acidification & most effective in soils with high CEC. ► pH influenced by respired CO 2, organic acids, applied fertilizer, and acid rain.  Cascading effects on biota and soil nutrients (Nitrifying microbes? Leaching?)

12. Biological properties presented by Tao of Fine Young Entisols and Emily of Soil Coughing

13. Soil Microbial Biomass & Nitrogen Cycling Soil Microbial Biomass & Microbial Respiration Soil Microbial Biomass & Microbial Respiration Nitrogen Mineralization and Nitrification Nitrogen Mineralization and Nitrification How plant and microbial activities interact through the exchange of C and N. How plant and microbial activities interact through the exchange of C and N.

14. Microbial Biomass - Soil microorganisms are generally C limited - Organic matter comes from above- and below- ground production of plant litter and dead microbial biomass. - Measure microbial respiration to calculate original microbial biomass (fumigated / control)

15. Soil Texture AWC (cm3 H2O/cm3 soil) pH (CaCl2)OM % Mixed-OakLoam0.3805.7123.918 Oak-HickorySandy Loam0.2625.3384.720 N. HardwoodsLoamy Sand0.1833.8553.020 N.OakSand0.2353.4632.058 Microb.Bio mass (gC/m2) Microb. Resp. (mg/g/d) Specific Resp. N Min.(g N/m2/d) N Nit.(g N/m2/d) C Resp./N Min. Mixed-Oak17.50425.260187.1730.6320.2125.183 Oak-Hickory9.15326.038647.9960.2100.00714.890 N. Hardwoods12.99625.046199.6520.3620.1937.168 N.Oak2.97011.538474.3750.1260.00311.154

16. Cont. - Low microbial biomass under high Soil OM condition can be explained by high Specific Respiration. - Specific Respiration is a better indicator of microbial physiological activity, rather than general respiration rate (per unit of soil) - High specific respiration indicates a less efficient microbial community.

17. N Mineralization & Nitrification Factors controlling N cycling: 1. Litter production, aboveground + belowground 2. Chemical composition of litter 3. Numbers and types of microorganisms 4. Physical factors (temp. and moisture)

18. Mineralization & Nitrification Cont. N Mineralization: N Mineralization: R-NH 3 + H 2 O = R-OH + NH 4 + Nitrification: Nitrification: Assimilated by plants NH 4 + Ion exchange reaction Oxidized to NO 3 - (nitrification) NH 4 + NO 2 - NO 3 - O2O2 O2O2 Energy H+H+

19. Soil Texture AWC (cm3 H2O/cm3 soil) pH (CaCl2)OM % Mixed-OakLoam0.3805.7123.918 Oak-HickorySandy Loam0.2625.3384.720 N. HardwoodsLoamy Sand0.1833.8553.020 N.OakSand0.2353.4632.058 Microb.Bio mass (gC/m2) Microb. Resp. (mg/g/d) Specific Resp. N Min.(g N/m2/d) N Nit.(g N/m2/d) C Resp./N Min. Mixed-Oak17.50425.260187.1730.6320.2125.183 Oak-Hickory9.15326.038647.9960.2100.00714.890 N. Hardwoods12.99625.046199.6520.3620.1937.168 N.Oak2.97011.538474.3750.1260.00311.154

20. Mineralization & Nitrification Cont. N mineralization & Nitrification are relatively low due to less microbial biomass. N mineralization & Nitrification are relatively low due to less microbial biomass. Very high C respiration/N mineralization indicates poor leaf litter quality (microbes interact with plants: microbes uptake C from plant litter and release N for plants to uptake). Very high C respiration/N mineralization indicates poor leaf litter quality (microbes interact with plants: microbes uptake C from plant litter and release N for plants to uptake). Although fairly neutral (slightly acidic, 5.98-6.47) and well aerated environment, nitrification is low. Although fairly neutral (slightly acidic, 5.98-6.47) and well aerated environment, nitrification is low. Most of NH 4 + is uptake by plants or attached to negative charged CEC complex system (clayey and OM rich in OH) before being nitrified Most of NH 4 + is uptake by plants or attached to negative charged CEC complex system (clayey and OM rich in OH) before being nitrified

21. Not shown by the lab data, but important to keep in mind: Very high percentage of coarse fragments, which dilute all the soil properties at an ecosystem level:Very high percentage of coarse fragments, which dilute all the soil properties at an ecosystem level: -Discount AWC -Discount nutrient availability -Discount soil OM content

22. 100 % 56% 18% 30 % Southwesterly wind sunlight Slope aspect Pits 1 to 5 are in order from the least weathered to the most weathered. But soil microbial activities and processes are not consistent with this trend.

23. Aspect OM % Bulk Density Micr. Biomass (gC/m2) Micr. Resp. (ug/g/d) Specific Resp. (mg/g/ d) N Min. (g N/m2/ d) Nitrifica -tion (g N/m2/d) C Resp./ N Min Pit 1-SW Top 1.73 %1.193.9322.41 678.1 60.1780.0038 14.98 1 Pit 2-NW Top 4.23 % 1.030 51.4425.90 1850. 000.3200.00068.355 Pit 3 -North Mid 6.57 %1.1618.6233.70 210.8 40.1760.0058 22.31 8 Pit 4 - SE Mid 6.42 %1.4313.1023.21 253.6 80.1940.0080 17.13 3 Pit 5 - NE Mid 4.65 %0.868.6724.97 247.3 10.1820.01911.663

24. Ecosystem C and nutrient pools…

25. “More carbon is stored in the world’s soils than in the world’s plant biomass and atmosphere combined.” ► Ecosystem biomass is the dry mass of living and non-living tissue within an ecosystem ► Biomass can be measured by quantifying OM (47% C) the nutrient pools ► The amount of OM accumulation in soil is driven by microbial respiration and ultimately NPP

26. ► NPP controls the flow of energy and nutrients in terrestrial ecosystems ► NPP = GPP – R a ► GPP – the amount of C fixed by plants on an ecosystem bases ► RA – Carbon dioxide lost during repair of enzymes and used in ion uptake ► NEP - net annual increment of all biomass on an ecosystem basis accounting for (R h ) the respiration of heterotrophic respiration.

27. 1. Above & belowground portions of over & under story trees 2. Mineral soil (Top 10 cm) 3. Forest floor 4. Woody debris 5. Tissue of heterotrophic organisms Five Major Nutrient Pools in Forest Ecosystems

28. TeamAbove GroundForest FloorSoil Carbon De La Solum102.4415.4439.99 Soil Coughing96.5311.1143.59 Duripan 172.427.576.59 Möttley Hüe111.43.03320.59 Fine Young Entisols226.376.4991.93

29. TeamAbove GroundForest FloorSoil Nitrogen De La Solum211.510.031032.0 Soil Coughing196.5772.2431236.6 Duripan 378.66491398 Möttley Hüe236.5519.711428 Fine Young Entisols486.2842.211718.4

30. ► Temperature and precipitation drive biomass productivity ► More weathered soils would be expected to have a higher amount of OM and N ► Soils with a more loamy texture had a higher amount of organic matter and a higher amount of nitrogen

31. Summary ► Factors influencing OH soil formation: 1. Climate (microsite variation  dif. profiles) 2. Living organisms 3. Parent material 4. Topography (strong influence on climate) 5. Time (looking at top sites similar to looking back in time!) ► 2 factors constant: PM and time.

32. ► OH site as microcosm of class concepts; soil formation depends on local conditions over long periods of time, soil characteristics exert strong influence on biota & ecosystem dynamics.

33. the end.