Fine-root respiration in a loblolly pine (Pinus taeda L.) forest exposed to elevated CO2 and N fertilization

Drake, JE; Stoy, PC; Jackson, RB; Delucia, EH

HERO ID

2470299

Reference Type

Journal Article

Year

2008

Language

English

PMID

18684240

HERO ID 2470299
In Press No
Year 2008
Title Fine-root respiration in a loblolly pine (Pinus taeda L.) forest exposed to elevated CO2 and N fertilization
Authors Drake, JE; Stoy, PC; Jackson, RB; Delucia, EH
Journal Plant, Cell and Environment
Volume 31
Issue 11
Page Numbers 1663-1672
Abstract Forest ecosystems release large amounts of carbon to the atmosphere from fine-root respiration (R(r)), but the control of this flux and its temperature sensitivity (Q(10)) are poorly understood. We attempted to: (1) identify the factors limiting this flux using additions of glucose and an electron transport uncoupler (carbonyl cyanide m-chlorophenylhydrazone); and (2) improve yearly estimates of R(r) by directly measuring its Q(10)in situ using temperature-controlled cuvettes buried around intact, attached roots. The proximal limits of R(r) of loblolly pine (Pinus taeda L.) trees exposed to free-air CO(2) enrichment (FACE) and N fertilization were seasonally variable; enzyme capacity limited R(r) in the winter, and a combination of substrate supply and adenylate availability limited R(r) in summer months. The limiting factors of R(r) were not affected by elevated CO(2) or N fertilization. Elevated CO(2) increased annual stand-level R(r) by 34% whereas the combination of elevated CO(2) and N fertilization reduced R(r) by 40%. Measurements of in situ R(r) with high temporal resolution detected diel patterns that were correlated with canopy photosynthesis with a lag of 1 d or less as measured by eddy covariance, indicating a dynamic link between canopy photosynthesis and root respiration. These results suggest that R(r) is coupled to daily canopy photosynthesis and increases with carbon allocation below ground.
Doi 10.1111/j.1365-3040.2008.01869.x
Pmid 18684240
Wosid WOS:000259817700012
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword carbon cycle; Duke FACE; FACTS-1; global climate change; net ecosystem exchange; soil respiration