Fire regime change and the boreal forest carbon cycle from 10,000 years ago to 2100 AD

Kelly, Ryan

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https://hdl.handle.net/2142/50349 Copy

Description

Title

Fire regime change and the boreal forest carbon cycle from 10,000 years ago to 2100 AD

Author(s)

Kelly, Ryan

Issue Date

2014-09-16

Director of Research (if dissertation) or Advisor (if thesis)

Hu, Feng Sheng

Doctoral Committee Chair(s)

Hu, Feng Sheng

Committee Member(s)

• Dietze, Michael C.
• Fraterrigo, Jennifer M.
• Higuera, Philip E.
• Walsh, John E.

Department of Study

Plant Biology

Discipline

Plant Biology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Boreal forest
• fire regime
• ecosystem ecology
• paleoecology
• global change biology
• climate change
• Arctic
• Holocene
• ecosystem modeling

Abstract

Boreal forests play an important role in the global carbon cycle, and wildfire is a key control of boreal carbon dynamics. Rapid high latitude climate change will likely alter boreal fire regimes, potentially disrupting the historical role of the biome as a major sink for anthropogenic carbon emissions. However, the brevity of observational fire records limits understanding of the trajectory and implications of such change. I addressed this limitation by reconstructing 10,000 years of paleoenvironmental history in the Yukon Flats of interior Alaska, incorporating the paleorecord into ecosystem model experiments, and applying insights from these approaches to the development of a statistical model for predicting fire regime change. Results reveal that recent burning is unprecedented in the last 10,000 years. Fire frequency fluctuations were the dominant control on carbon dynamics of the past millennium, and the increase in fire activity over the past several decades has caused large regional carbon losses. Fuel limitation due to fire-vegetation feedback dampened fire regime responses to centennial climate variability in the past, and a statistical model based on recent fire observations predicts that this mechanism will strongly attenuate future increases in fire activity. However, the exceptional magnitude of anthropogenic climate change will cause a pronounced increase in the rate of boreal forest burning in spite of vegetation feedback. As a result, dramatic shifts in ecosystem composition are likely across boreal Alaska, and the region will serve as a persistent source of atmospheric carbon throughout the 21st century.

Graduation Semester

2014-08

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http://hdl.handle.net/2142/50349

Copyright and License Information

Copyright 2014 Ryan Kelly

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