Publications

The Oregon Labor Day fires of 2020 collectively burned over 1,000,000 acres. That year, more than 10,000,000 acres burned across the western US that caused nearly $20 billion dollars in damages. This study is focused on the post-fire effects on a young industrial timber plantation that we were monitoring very carefully for years prior as part of another project, but it burned up in the Holiday Farm Fire.

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).

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!”

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.

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

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.

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.

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.

Although the field of soil science is literally studying the land we live on, very rarely do we ask how this land came to be managed by the current people in power. In this paper we examine how America’s past influences the current system of private and public land management agencies, and what we must do within the field of soil science to make a science for all people.

Studying wildfire effects on ecosystems is difficult because predicting where and when something will burn is nearly impossible, and rarely do you have robust pre-fire data. My dissertation samples from the Great Smoky Mountain National Park were collected prior to the Chimney Tops 2 from 2016. It was a wind-driven high intensity and high severity fire that burned >4,500 hectares. In this paper, we examine the pre and post fire pyrogenic carbon signal using an innovative BPCA method developed by Dr. Matosziuk.

The National Ecological Observatory Network (NEON) integrates hard infrastructure along with cloud-based data products that are publicly available. In this paper we advertised just some of the capabilities that NEON currently has, and describe how other site-specific instruments/observations may be incorporated.

Growing trees can take a whole lifetime, so you better know if your site nutrition status changes following harvest. Here we looked at a few sites in the PNW to examine how the antecedent conditions helped to buffer the soils to changes to the nutrient capacity of the site.

Finding carbon in soils is easy, tracing where it came from is hard and tracing that carbon down the soil profile is even harder. Here I presented some of my dissertation work where we examine plant derived carbon compounds across the NEON sites, and down soil profiles often reaching 1-meter or more in depth.

Spodosols are the most photogenic soils (personal opinion). Their dark organic surface horizons, followed by a light colored mineral horizon, then bookend-ed with another very dark - often red - mineral horizon makes these tri-colored soils magnificent to stare at. These Spodosols are relatively rare, but concentrated in a few places in the US where historical anthropogenic emissions are the most likely sources of Mercury. In this paper we focus on different Spodosols around the US, combining pedologic and geochemical analysis to identify how carbon and mercury interact down the soil profile.

There’s a lot of interest around fires effects on soil. What’s less often discussed is how well the soil records fire by the presense of Pyrogenic Carbon (PyC). We used the NEON sites and quantified how much PyC was present, and its relative quality, down soil profiles often reaching 1-meter in depth. Turns out, fire was everywhere.

Forest soils are can be resilient to harvesting, but what about two or three or four rotations worth of biomass removals? Here I present some work from my Masters, combining it with one chapter of my dissertation on the resilience of soil-C following harvesting (it’s all the roots!)

I hope you enjoy my Masters Defense. It was a labor of love.