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

Review of Field Data Mixed Oak Site 1 (Deborah) Site 2 (Chris) Site 3 (Mary) Site 4 (Cat) Total BA Lab Soil Texture Analysis Loam Soil Profile Site 1Site 3Site 2Site 4 Oi/Oe A E Bt B N/A C

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.

Available Water Content  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.

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.

Chemical Properties DebChrisMaryCatMean pH H 2 O pH CaCl OM(%) Total Acidity [cmol(+)/kg] CEC [cmol(+)/kg] Base Saturation (%)

MO Chemical Properties  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

 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 Biomass of all ecosystems studied  Large Discrepancy between aboveground biomass and forest floor biomass - rapid decomposition Nutrient Pools

 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. Nitrogen Mineralization

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. Microbial Biomass and Respiration

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

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

MO is a Highly Productive System