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Black carbon in grassland ecosystems of the world
Author(s) -
Rodionov Andrej,
Amelung Wulf,
Peinemann Norman,
Haumaier Ludwig,
Zhang Xudong,
Kleber Markus,
Glaser Bruno,
Urusevskaya Inga,
Zech Wolfgang
Publication year - 2010
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2009gb003669
Subject(s) - steppe , chernozem , environmental science , soil carbon , holocene , ecosystem , grassland , total organic carbon , radiocarbon dating , soil organic matter , carbon cycle , isotopes of carbon , physical geography , environmental chemistry , soil science , soil water , ecology , geography , chemistry , archaeology , biology
Black carbon (BC) is the product of incomplete burning processes and a significant component of the passive soil organic carbon (SOC) pool. The role of BC in the global carbon cycle is still unclear. This study aimed to quantify and characterize BC in major grassland ecosystems of the world. Twenty‐eight representative soil profiles (mainly Mollisols) were sampled in the Russian Steppe, the U.S. Great Plains, the Argentinian Pampa, the Manchurian Plains in China, and the Chernozem region in central Germany. Black carbon contents were estimated using benzene polycarboxylic acids (BPCA) as a molecular marker, and indications about the origin of the BC were derived from bulk and compound‐specific δ 13 C analyses and radiocarbon dating of bulk soil organic matter (SOM). Our findings suggest that between 5% and 30% of SOC stocks consist of BC. Maximum BC contributions to SOC frequently were found at deeper parts of the A horizon with 14 C ages younger than 7000 years BP; that is, incorporation of C as charred particles accompanied ecosystem development since the mid‐Holocene. Most of this BC formed from local vegetation, as indicated by a 13 C isotope signature similar to that of bulk SOM. At some sites, also nonlocal sources contributed to soil BC, e.g., fossil fuel BC inputs at the German sites. Black carbon stocks were highest in Chernozems and lowest in Kastanozems. The Russian Steppe and Chinese Manchurian sites stored about 3–4 times more BC (around 3 kg m −2 ) than did the other sites because of thicker A horizons that were rich in BC. On a global scale, we estimate that steppe ecosystems contain between 4 and 17 Pg BC.