Current Research
My PhD research is attempting to better understand various controls on soil carbon dynamics. I'm especially interested in the interactions between human activity and environmental and pedologic factors.
Effects of long-term nitrogen fertilization on soil carbon cycling
Atmospheric nitrogen deposition is projected to increase, with unknown implications for ecosystem processes. I am using a 15 year nitrogen fertilzation experiment in the Luquillo Experimental Forest in Puerto Rico to investigate the effect of chronic elevated nitrogen levels on soil carbon cycling in two different forests. I am conducting density fractionation of soil organic matter and measuring radiocarbon to model carbon cycling rates. This will hopefully improve our understanding of the effects of nitrogen enrichment across a variety of ecosystems.
Role of iron an aluminum in soil carbon stabilization
There is a growing body of research suggesting that iron and aluminum (oxy)hydroxides may play an important role in controlling organic matter stabilization in many soils. Using the same soil samples from my MS research, I will be investigating relationships between various forms of iron and aluminum and carbon across a wide range of soil types.
Effects of secondary forest succession on soil carbon across soil types
Pasture to forest conversion is an important ongoing land use transition in the tropics, but the response of soil carbon is inconsistent. Soil properties may mediate the response of soil carbon. I am hoping to address this uncertainty and explore how soil carbon changes through reforestation on two related soils with different weathering histories and properties.
Effects of long-term nitrogen fertilization on soil carbon cycling
Atmospheric nitrogen deposition is projected to increase, with unknown implications for ecosystem processes. I am using a 15 year nitrogen fertilzation experiment in the Luquillo Experimental Forest in Puerto Rico to investigate the effect of chronic elevated nitrogen levels on soil carbon cycling in two different forests. I am conducting density fractionation of soil organic matter and measuring radiocarbon to model carbon cycling rates. This will hopefully improve our understanding of the effects of nitrogen enrichment across a variety of ecosystems.
Role of iron an aluminum in soil carbon stabilization
There is a growing body of research suggesting that iron and aluminum (oxy)hydroxides may play an important role in controlling organic matter stabilization in many soils. Using the same soil samples from my MS research, I will be investigating relationships between various forms of iron and aluminum and carbon across a wide range of soil types.
Effects of secondary forest succession on soil carbon across soil types
Pasture to forest conversion is an important ongoing land use transition in the tropics, but the response of soil carbon is inconsistent. Soil properties may mediate the response of soil carbon. I am hoping to address this uncertainty and explore how soil carbon changes through reforestation on two related soils with different weathering histories and properties.
Past Research
My M.S. research investigated the influence of human land use on soil carbon storage across a wide range of soil types and climatic variation. It is known that soil carbon represents a substantial fraction of terrestrial carbon storage, but there is considerable uncertainty in how soil carbon responds to land use change. Much of this uncertainty could be due to the confounding effects of environmental variables. To address this uncertainty, I used soil samples collected by the Natural Resource Conservation Service across the island of Puerto Rico and the US Virgin Islands. The samples came from 5 different land uses and from multiple soil orders on sites with a wide precipitation gradient.
Aquatic carbon cycling in Siberia
As an undergraduate I had the opportunity to travel to northeastern Siberia as a member of the Polaris Project. My project looked at the role of benthic macroinvertebrates in aquatic carbon cycling. We classified the major invertebrate taxa found in Siberian streams and ponds and also implemented a bottle experiment to measure the effect of amphipods on the conversion rate of particulate organic matter to dissolved organic matter. We found lots of bugs and little effect of the amphipods on particulate matter transformation.
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Other Projects
I have worked as a field assistant on two forest ecology projects. The B4Warmed project through the University of Minnesota was looking at the response of boreal and temperate tree seedlings to increased temperatures at the boreal/temperate ecotone in northern Minnesota. The other project through the University of Puerto Rico, investigated tree species distribution and population dynamics along a forest successional chronosequence. I also did an independent study project on the Andean Cock-of-the-rock in Ecuador that gave me a new appreciation for study organisms/systems that don't move or wake up at 5:30 AM.
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