Moisture-driven divergence in mineral-associated soil carbon persistence

Soil carbon "sequestration" is all the rage now a days, but very rarely does anyone define the time-frame of "sequester". Usually folks are only looking at changes to soil carbon *content*, and assuming those changes are permanent. They are not. Here we show that soil carbon *content* is de-coupled from how long that soil carbon stays in soil (i.e. having more carbon in soils does not necessary mean that carbon sticks around for longer periods of time).

I finished my PhD!

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.

Lignin and fungal abundance modify manganese effects on soil organic carbon persistence at the continental scale

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!"

The Impact of freeze-thaw history on soil carbon response to experimental freeze-thaw cycles

Permafrost soils are some of the coolest things I've ever seen, and the primary author, Dr. Erin Rooney, is showing us all her chemistry skills from the second chapter of her dissertation. If you want to see her first chapter, see her other permafrost paper above that describes some of the *physical* changes to permafrost when it undergoes freeze thaw cycles. But this paper is about the *chemical* changes that occur, and what that could mean for arctic-permafrost nutrient cycling.

Soil pore network response to freeze-thaw cycles in permafrost aggregates

Permafrost soils are finally getting the attention they deserve. Unfortunately, they may not be around much longer because of how quickly they are thawing. Here we explore what happens during freeze-thaw cycles that may alter their future behavior

Climate Effects on Subsoil Carbon Loss Mediated by Soil Chemistry

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.

Key predictors of soil organic matter vulnerability to mineralization differ with depth at a continental scale

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.

Big Data for Big Problems - The National Ecological Observatory Network (NEON)

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.

Patterns and predictors of soil organic carbon storage across a continental-scale network

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.

Divergent controls on carbon concentration and persistence between forests and grasslands of the conterminous US

Chicken or the egg. Grassland soil carbon behaves different than forest soil carbon. But is that because of the plant composition? (No). Or is it because of the climatic differences? (Probably) But if the climatic differences *also* lead to vegetation differences, then how can you separate out the climate from the vegetation? Here we attempt to do so.