Premium
Respiratory carbon loss of calcareous grasslands in winter shows no effects of 4 years’ CO 2 enrichment
Author(s) -
Volk M.,
Niklaus P. A.
Publication year - 2002
Publication title -
functional ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 154
eISSN - 1365-2435
pISSN - 0269-8463
DOI - 10.1046/j.1365-2435.2002.00609.x
Subject(s) - respiration , biology , temperate climate , growing season , ecosystem , grassland , biomass (ecology) , calcareous , zoology , carbon cycle , soil respiration , carbon dioxide , ecosystem respiration , carbon fibers , agronomy , ecology , primary production , botany , materials science , composite number , composite material
Summary1 CO 2 exchange measurements in long‐term CO 2 ‐enrichment experiments suggest large net carbon gains by ecosystems during the growing season that are not accounted for by above‐ground plant biomass. Considerable amounts of C might therefore be allocated below ground. 2 Winter ecosystem respiration from temperate grasslands under elevated CO 2 may account for the loss of a significant part of the extra C gained during the growing season. To test this hypothesis, dark respiration was assessed throughout the winter of the fourth year of CO 2 enrichment in a calcareous grassland. 3 Using these data, a model was parameterized to estimate whole‐winter respiratory CO 2 losses. From November to February, 154 9 g C m −2 were respired under elevated CO 2 and 144 5 g C m −2 under ambient [CO 2 ], with no significant difference between the CO 2 treatments. 4 We conclude that (i) wintertime respiration does not constitute a larger C loss from the ecosystem at elevated CO 2 ; and (ii) the absence of respiratory responses implies no extra growing‐season C inputs with month‐to‐year turnover times at elevated CO 2 .