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Elevated CO 2 and elevated temperature have no effect on Douglas‐fir fine‐root dynamics in nitrogen‐poor soil
Author(s) -
Johnson M. G.,
Rygiewicz P. T.,
Tingey D. T.,
Phillips D. L.
Publication year - 2006
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.1469-8137.2006.01658.x
Subject(s) - nitrogen , standing crop , soil water , douglas fir , crop , nutrient , agronomy , environmental science , chemistry , horticulture , zoology , botany , biology , biomass (ecology) , soil science , ecology , organic chemistry
Summary• Here, we investigate fine‐root production, mortality and standing crop of Douglas‐fir ( Pseudotsuga menziesii ) seedlings exposed to elevated atmospheric CO 2 and elevated air temperature. We hypothesized that these treatments would increase fine‐root production, but that mortality would be greater under elevated temperature, leading to a smaller increase in standing crop. • Seedlings were grown in outdoor, sun‐lit controlled‐environment chambers containing native soil. They were exposed in a factorial design to two levels of atmospheric CO 2 and two levels of air temperature. Minirhizotron methods were used to measure fine‐root length production, mortality and standing crop every 4 wk for 36 months. • Neither elevated atmospheric CO 2 nor elevated air temperature affected fine‐root production, mortality, or standing crop. Fine roots appeared to root deeper in the soil profile under elevated CO 2 and elevated temperature. • Low soil nitrogen (N) levels apparently limited root responses to the treatments. This suggests that forests on nutrient‐poor soils may exhibit limited fine‐root responses to elevated atmospheric CO 2 and elevated air temperature.