CAREER: COMPOSITION, TRANSPORT, AND FATE OF DISSOLVED AND PYROGENIC ORGANIC MATTER IN FIRE-IMPACTED SOILS

About This Grant

This project will advance our understanding of soil processes that control the amount of carbon stored in soil. Understanding the controls on soil carbon storage and loss are critical for managing our natural environment for plant productivity, for improving our water quality, and for mitigating the effects of anthropogenic climate change. This project involves a series of experiments that will describe how fire and erosion impact the storage of carbon in soil, how it is chemically transformed over time, and how it may impact water quality. The results of this work will inform land managers in both urban and forested areas make management decisions to improve productivity, increase carbon storage, and improve water quality. The educational component of this project will make collected data publicly available for educators in teaching modules that can be freely used to teach about soil, water quality, and the natural environment. The aim of this research project is to determine the relative importance of burn severity, soil type, erosion, and time since fire as drivers of dissolved organic matter (DOM) and pyrogenic carbon (PyC) quality and quantity in soils and outflow water. This work will be achieved by (1) collecting intact soil cores from plots with differing burn severities and conducting simulated leaching experiments to quantify throughflow of PyC and DOM, (2) establishing sediment fences to describe the role of burn severity on sediment and the related DOM quality from water extracted sediments to demonstrate the importance of sediment as a source of PyC into DOM, and (3) establish a tree vault study with applied PyC (as biochar) with two soil types (sandy and clay; typical of Georgia, USA) to describe the rate and quality of throughflow of applied PyC over longer time scales. Coupling these field and laboratory studies on different temporal and experimental scales will reveal the relative importance of different controls on the formation and transport of DOM and dissolved PyC, a significant and not well understood component of the global soil carbon cycle. This project is supported by the Life and Environments through Time (LET) program, and the Water, Landscape, and Critical Zone Processes (WaLCZ) program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.