Carbon Cycle
Aims to observe and understand the exchange of carbon and coupled elements among Earth’s atmosphere, oceans and land ecosystems (natural and managed).
- What are the driving mechanisms responsible for the accumulation of organic matter in biomass and soils?
- How is land cover and land use affecting net carbon exchange?
- What are the relationships between terrestrial carbon exchange and climate trends and variability?
- How do deposition of ozone, nitrogen, and other pollutants impact uptake of CO2 by forests?
- What is the high resolution space/time distribution of fossil fuel CO2 emissions and how can the driving process be simulated?
- How do collective and individual actions by farmers and other land users affect carbon management and sequestration initiatives?
Understanding what controls the short and long term accumulation of carbon in terrestrial ecosystems is a crucial element in improving climate change projections because the carbon-climate feedback has emerged as one of the most critical linkages in climate change research. Understanding carbon exchange mechanisms will improve not only climate change projections but also public policy and natural resource management options. Reliable and accurate information will enable carbon reduction strategies, help drive renewable energy production, improve climate projections and allow us to anticipate the regional impacts of climate change.
Brown-rot Fungal Mechanisms as a Model for Biomass Saccharification - – Tim Filley (Funding from DOE)
Brown rot wood-degrading fungi accomplish naturally what bioconversion technologies currently do not: complete removal (>99%) of plant polysaccharides from lignocellulosic tissues without removing or damaging lignin. The lignin modifications (demethylation, side chain oxidation, hydroxylation) seen in residues from brown rot fungi may be an important link to understanding fungal mechanisms of sugar release (saccharification).
Soil-Earthworm-Litter System Controls on the Stabilization of Organic Matter in Eastern Deciduous Forests - – Tim Filley (Funding from DOE)
This work will employ detailed molecular, isotopic, mineralogical, ecological and microbiological methods to develop a mechanistic understanding of the processes that control soil organic matter storage in a system with a intense gradient in earthworm activity. The earthworm-litter-soil system is particularly relevant today as most identified earthworm species in this region’s forests are non-native, and it is anticipated that over the next few decades they will expand farther into northern forests driven by rising surface temperatures, and local factors such as soil transport, discarded fishing bait, and land use change.
Collaborative Research: Dynamics of Carbon Release and Sequestration: Case Studies of Two Early Eocene Hyperthermals - Gabe Bowen (Funding from NSF)
The Earth's climate was restless during the early part of the Eocene epoch. During several dramatic twitches, global temperatures warmed dramatically and then settled back to normal levels after 100 thousand years or more. Carbon isotope ratio data and records of carbonate preservation on the ancient seafloor tell us that each twitch was accompanied by abrupt increases in the level of carbon dioxide in the atmosphere and oceans.
Soil Carbon Responses to Atmospheric CO2 Enrichment - Timothy Filley (Funding from DOE)
To date, most field-scale CO2 enrichment studies have been unable to detect significant changes in soil C against the relatively large, spatially heterogeneous pool of existing soil organic matter, leading some to conclude that the potential for increased soil C is limited. A further concern is that any CO2-stimulated increases in soil C will be allocated primarily to rapidly cycling, labile pools with little, if any, long-term stabilization.
The Hestia Project: Supporting Climate Science, Policy and Planning at Purdue - Kevin Gurney (Funding from The Showalter Trust)
This project will build an inventory of fossil fuel CO2 emissions for the city of Indianapolis in which all CO2 emissions and their underlying driver activity will be simulated and visualized using a high resolution, 3-D environment. This proposed "test" case is part of a much larger project called "Hestia" which will perform the same function for the entire planet.
Collaborative Research: Impacts of vegetation change on stabilization and microbial accessibility of soil organic matter: A microbiological, isotopic and molecular study - Tim Filley (Funding from NSF).
Soil organic matter (SOM) represents the largest pool of actively cycling organic carbon and nitrogen in the terrestrial environment; however, incomplete understanding of the complex interactions among plants, soils, and microbes limits our ability to quantitatively account for the storage and dynamics of these elements in global budgets.
"Collaborative Research: Impact of Permafrost Degradation on Carbon and Water in Boreal Ecosystems," Qianlai Zhuang (Funding from NSF)
The Boreal Forest contains about one-third of all global terrestrial carbon stored as vegetation and soil organic matter. The fate of this carbon, however, is uncertain because of the widespread degradation of permafrost, which plays a key role in sequestering soil carbon. If the climate warms another 5 to 8oC in Alaska, as predicted by the IPCC (2001), nearly all the permafrost could be eliminated from this biome, causing dramatic changes in the water and carbon balance of boreal ecosystems.