I successfully defended my PhD, and had a lot of [type II] fun in the process. You can watch my presentation, look through my slides, and access my *draft* dissertation that still requires more edits before it's finalized. Enjoy.
Too many people focus on surface soils, and too many people ignore Manganese (Mn)! If you don't know about Mn's role in ecosystems processes, the introduction is expertly written by Dr. Angela Possinger (also the primary author) and is worth reading over. We show that Mn abundance at the continental scale is highly variable, but that it can be predictive of certain soil carbon metrics (especially lignin abundance). But, the effects of Mn is pretty unique on location, and at each horizon in the soil illustrating the old addage "it's all about site specificity!"
Too many people focus on surface soils, and they're missing out on most of the (soil carbon) action when they do. Here we show that ecosystems favoring forests (wetter, more iron and aluminum) release more CO2 compared to grassland-like ecosystems (dryer, more calcium and magnesium). As our earth warms, we need to consider not only how surface soils will change due to management, but how subsurface soils (where most of the carbon is) will respond due to climate change.
SOM *storage* is not the same as its *vulnerability*. This was a 1-yr incubation experiment from NEON's A and B horizons ran by Tyler Weiglein at Virginia Tech as his Masters degree. We found that predictors of soil carbon vulnerability (based on CO2 respiration) were different for surface and subsurface horizons. Turns out, you need to dig deeper to find out the whole story on soils.
The NEON project was at its infancy when I began my dissertation. They were literally building and installing the ~30 sites around North America at the same time they were sampling soils for my project. Although my PhD focuses on the soils aspect, there is a wealth of publicly available data being generated that any scientist should be aware of.
SOM looks different across ecosystems. This is an attempt to examine whether SOC composition at the local scale can be represented at the regional/ecosystem scale.