1. Radrick Forest: A Mixed Oak Ecosystem
Well Developed Soil
Productive Ecosystem
Radrick Forest: A Mixed Oak Ecosystem

2. Outline Re-introduction to Radrick Forest Soil characteristics:
Physical
Chemical
Biological
Synthesis: How do the factors above combine to influence soil formation and ecosystem development?

3. Glacial History of Michigan

5. Soil Formation Why does Radrick have well developed soil? Climate
Soil type
Mixed Oak
Loam
Oak-Hickory
Sandy Loam
N. Hardwoods
Loamy Sand
Black Oak/White Oak
Sand
Why does Radrick have well developed soil?
Climate
Glacial History
Parent Material

6. Chemical properties of the mixed oak ecosystem
pH (DI water)
pH (CaCl2)
CEC (cmolc/kg)
% Base Saturation
Mixed Oak
6.14
5.71
8.57
0.99
Oak Hickory
4.98
4.19
10.78
Northern Hardwoods
4.50
3.11
4.03
0.93
Black Oak/White Oak
3.50
2.63
1.90
0.13

7. Comparison graph for pH and CEC

8. Why do we see these differences?
Parent material may explain the north/south data
But, OH and MO share the same parent material, so we look to weathering and %organic matter
These play into soil texture; MO is the most clayey of the sites.
The MO profile is highly developed and has a strong buffering capacity.

9. But total microbial activity is not much different;
Radrick Forest Microbial Carbon Utilization Compared to Other Ecosystems
Mixed Oak has relatively high levels of microbial biomass compared to other ecosystems;
But total microbial activity is not much different;

10. Composition of microbial community?
Discussion of Microbial Activity in Radrick Forest: What factors explain why MO has high microbial biomass, but low activity?
Composition of microbial community?
-A higher proportion of actinomycetes would tend to result in lower respiration, but unlikely to account for the higher biomass.
-A high proportion of bacteria would account for a higher biomass, but not for the low activity.
-A higher presence of fungi would account for the higher biomass, and possibly into lower respiration, if C is incorporated in building biomass rather than respired.
Other Potential Factors:
Presence of organic matter?
Radrick forest has a moderate level of soil organic matter.
Soil physical characteristics?
The more clayey texture of the MO system would tend to reduce gaseous diffusion, causing locally increased CO2 levels, thus slowing respiration rates even with a high microbial biomass.
Soil chemical characteristics?
The overall pH is moderate, and not particularly conducive to fungi. But poor diffusion could create microzones with high CO2 concentrations, and low pH.
It may explain
It may explain
It may explain
It may explain

11. Radrick Forest Mineralization and Nitrification Compared to Other Ecosystems
Mixed Oak has a high rate of N Mineralization compared to other ecosystems;
Efficiency of MO

12. Radrick forest has:
highest above ground biomass
highest litter production
intermediate soil organic matter

13. *High decomposition rate
Why does Radrick forest not have the highest soil organic matter?
*High decomposition rate
Near neutral PH,
Sufficient soil moisture
Good aeration and
Relatively warm climate
High litter quality
* Relatively lower allocation
to root and n nutrient-rich ecosystem

15. Why is the soil OM in Radrick forest such a big pool of N?
1. Clayey soil with high CEC  large amount of inorganic N is bound
2. Contain some species with nutrient-rich tissue  higher litter quality. (N concentration in forest floor = 1.35%)
(even higher than NH??)
3. High microbial biomass can be part of the pool
Species
Relative
Dominance (%)
Leave N
concentration(%)
Branch N
Blake Oak (Quercus velutina)
8.5
1.19
0.39
Red Maple (Acer rubrum)
13.1
2.29
0.59
Sassafras (Sassafras albidum)
15.0
Bitternut Hickory (Carya cordiformis)
25.2
1.31
0.45
Red Oak (Quercus rubra)
33.4
1.23
0.42
Shagbark Hickory (Carya ovata)
1.2
Black Cherry (Prunus serotina)
3.6
2.11
0.48

16. Radrick Forest has highest aboveground biomass, faster nutrient uptake
Effect of high nitrification:
Negatively charged nitrate ions are not adsorbed by the negatively charged colloids, so it leaches out of the ecosystem easily.

17. Nutrient tightly bound within the ecosystem
Climate:
Relatively warm and humid
Low fire frequency
Nutrient tightly bound within the ecosystem
High Above
ground biomass
High quality of both above- and below- ground litter
Fast uptake
High rate of decomposition and mineralization
Soil:
*Fine texture *Calcareous parent material *High water availability *High PH *High CEC
Large soil microbial community
Low leaching

18. Thanks!!