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Does greater night‐time, rather than constant, warming alter growth of managed pasture under under ambient and elevated atmospheric CO 2 ?
Author(s) -
Volder A.,
Edwards E. J.,
Evans J. R.,
Robertson B. C.,
Schortemeyer M.,
Gifford R. M.
Publication year - 2004
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.1469-8137.2004.01025.x
Subject(s) - global warming , environmental science , daytime , atmospheric sciences , biomass (ecology) , zoology , agronomy , climate change , ecology , biology , geology
Summary• This study examined the effects of warming, elevated atmospheric CO 2 and cutting regimen on the growth of Phalaris aquatica cv. Holdfast swards. • Six temperature gradient tunnels (TGT) were used to manipulate both air temperature and atmospheric CO 2 concentrations (ambient and 750 ppm). Within each tunnel, there were three temperature treatments: no warming, constant warming of +3.0°C and a daytime warming of 2.2°C combined with a night‐time warming of 4.0°C and two defoliation frequencies. • Averaged across 20 months of growth, there was a positive effect of elevated atmospheric CO 2 (+11%), no effect of either warming treatment and a negative effect of frequent cutting (−19%) on total above ground biomass production. The responses to all treatments, however, were strongly seasonal. • Positive responses to CO 2 were statistically significant only in the spring, when plant growth was strongest. No evidence was found that high night‐time warming had different effects on plant growth and plant responses to elevated atmospheric CO 2 , than constant warming.