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Soil respiration, root biomass, and root turnover following long‐term exposure of northern forests to elevated atmospheric CO 2 and tropospheric O 3
Author(s) -
Pregitzer Kurt S.,
Burton Andrew J.,
King John S.,
Zak Donald R.
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2008.02564.x
Subject(s) - biomass (ecology) , soil respiration , respiration , primary production , environmental science , agronomy , carbon dioxide , ecosystem , carbon cycle , soil carbon , tropospheric ozone , soil water , ozone , chemistry , botany , biology , ecology , soil science , organic chemistry
Summary• The Rhinelander free‐air CO 2 enrichment (FACE) experiment is designed to understand ecosystem response to elevated atmospheric carbon dioxide (+CO 2 ) and elevated tropospheric ozone (+O 3 ). The objectives of this study were: to understand how soil respiration responded to the experimental treatments; to determine whether fine‐root biomass was correlated to rates of soil respiration; and to measure rates of fine‐root turnover in aspen ( Populus tremuloides ) forests and determine whether root turnover might be driving patterns in soil respiration. • Soil respiration was measured, root biomass was determined, and estimates of root production, mortality and biomass turnover were made. • Soil respiration was greatest in the +CO 2 and +CO 2 +O 3 treatments across all three plant communities. Soil respiration was correlated with increases in fine‐root biomass. In the aspen community, annual fine‐root production and mortality (g m −2 ) were positively affected by +O 3 . • After 10 yr of exposure, +CO 2 +O 3 ‐induced increases in belowground carbon allocation suggest that the positive effects of elevated CO 2 on belowground net primary productivity (NPP) may not be offset by negative effects of O 3 . For the aspen community, fine‐root biomass is actually stimulated by +O 3 , and especially +CO 2 +O 3 .