Mixed Oak Ecosystem: Field and Lab Data Integration

1. Mixed Oak Ecosystem:Field and Lab Data Integration Deborah Hudleston Catherine Resler Mary Walton Chris Weber

2. Review of Field Data

3. Soil Texture • Loam textured soil was found at all Mixed Oak sites sampled. • Mixed oak has a greater amount of clay compared to the other three sites sampled. • > amount of rich clay minerals fosters higher NPP.

4. Available Water Content • < Amount of Larger Particles -> Decrease in Pore Size= Greater AWC • Mixed Oak has a greater amount of clay than sand compared to the other three sites sampled, therefore a higher AWC.

5. Bulk Density • Well-structured soils have > amounts of macropores -> a higher water-holding capacity than less developed soils. • Mixed Oak had a larger bulk density than the other three sites sampled.

6. Chemical Properties

7. pH Calcium rich parent material Buffer to weathering Organic Matter Oak/maple leaves; moderate A Horizon Large above ground biomass- rapid decomposition CEC/ Base Saturation Large CEC 98% base saturation Lots of nutrients for plants Consistent with soil type MO Chemical Properties

8. Nutrient Pools • Largest biomass pool of the Mixed Oak ecosystem is aboveground • Largest pool of N in Mixed Oak ecosystem is in the belowground pool • Highest Aboveground Biomassof all ecosystems studied • Large Discrepancy between aboveground biomass and forest floor biomass - rapid decomposition

9. Nitrogen Mineralization • Net N mineralization is highest in the MO ecosystem - high-lignin litter of the oak trees provide a poor quality substrate to microbial decomposers. • Microbes receive little energy from the lignified litter, supporting little microbial growth, and resulting in low microbial N sink, making the N available to plants.

10. Microbial Biomass and Respiration • Microbial respiration is low – indicating low microbial activity • Specific respiration is low - each individual decomposes a relatively small amount of C for the N produced • The ratio of C respired to N mineralized is one of the smallest of the 4 ecosystems - this is a further indication of the poor quality of the oak leaf litter as substrate for decomposers.

11. Biological Property Connections High Aboveground Biomass Substantial High-Lignin Litter Production High Plant Available N High N mineralization Poor Quality Substrate for Microbial Decomposers

12. Summary Soil Development (Clay = High bulk density and AWC) Physiography NUTRIENT RICH SITE WELL DEVELOPED SOIL High CEC and base saturation = High nutrients Climate High N mineralization High biomass

13. MO is a Highly Productive System