serc presentation
TRANSCRIPT
How Soil Correlates with
Tree Distribution and Diversity
James Biddle
Special Thanks➔Sean McMahon➔Geoffrey Parker➔Jessica Shue ➔Ben Turner➔Laureen Echiverri ➔Dan Gustafson & Lauren Nuzzi
Outline➔Overview of Summer Work➔A Focus on Nutrients and Productivity ➔Questions and Hypothesis➔Methods➔Findings➔Conclusion and Future Directions
So What?● Is there an impact of soil nutrients on
the distribution of tree species at SERC?
● What other factors influence tree dispersal?
● Why does this matter?
The Projects●SI-GEO Soil Carbon Census●Dendrometer Band Sampling ● Innovative Photo-Based Tree
Measurement ●Weekly Micro Cores of Beech
Trees
ForestGEO Network
Sixteen Hectares. Four Hundred Forty-Eight Samples.
Collection Methods● 1-2 People in the Field● Drilling Through Mud, Clay,
Sand, Roots, Rocks
Processing Methods●Soil Collected ●Removed roots and measured
weight●Measured soil moisture●50g samples sent to STRI
Carbon Project Future●Carbon content analyzed●Spatial maps●Further analyses of tree
diversity and soil interactions
Soil Nutrient Collection Sites
SI-GEO Topography
Distribution of Moisture
Correlation Between Soil Moisture & Elevation
Technical Terms● Effective Cation Exchange Capacity (ECEC) is the
amount of exchangeable cations found on solid soil particles
● These cations are Ca, Mg, Na, and K, and many others
● Resin bags in the soil collect the nutrients floating in the soil solution instead of the solid particles
● Focusing on Calcium collected using the resin bag method
Distribution of ECEC
Distribution of Calcium
Distribution of Phosphorus
Distribution of Water pH
Distribution of Calcium and Sweetgum
Distribution of Water pH and Tulip Poplar
Distribution of ECEC and American Beech
Distribution of Water and Spicebush
Conclusions"Correlation is not causation...”
“but it sure is a hint.”- E.R. Tufte
● Many variables affecting tree distribution● Strong relationship between moisture and dispersal● Nutrients have impact, easier to see in flat areas
with consistent soil moisture
Next Steps● More complete picture of what impacts tree
dispersal with integration of soil carbon census
● Further data analysis could reveal exciting correlations
● New connections within nature● Comparisons to other Forest GEO plots
Questions?