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A Holocene record of climate‐driven shifts in coastal carbon sequestration
Author(s) -
Mitra Siddhartha,
Zimmerman Andrew R.,
Hunsinger Glendon B.,
Willard Debra,
Dunn Joshua C.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036875
Subject(s) - environmental science , holocene , carbon sequestration , climate change , total organic carbon , deposition (geology) , paleoclimatology , organic matter , climatology , oceanography , sediment , geology , ecology , carbon dioxide , environmental chemistry , chemistry , paleontology , biology
A sediment core collected in the mesohaline portion of Chesapeake Bay was found to contain periods of increased delivery of refractory black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs). The BC was most likely produced by biomass combustion during four centennial‐scale dry periods as indicated by the Palmer Drought Severity Index (PDSI), beginning in the late Medieval Warm Period of 1100 CE. In contrast, wetter periods were associated with increased non‐BC organic matter influx into the bay, likely due to greater runoff and associated nutrient delivery. In addition, an overall increase in both BC and non‐BC organic matter deposition during the past millennium may reflect a shift in climate regime. The finding that carbon sequestration in the coastal zone responds to climate fluctuations at both centennial and millennial scales through fire occurrence and nutrient delivery has implications for past and future climate predictions. Drought‐induced fires may lead, on longer timescales, to greater carbon sequestration and, therefore, represent a negative climate feedback.