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Differential responses of root uptake kinetics of NH 4 + and NO 3 − to enriched atmospheric CO 2 concentration in field‐grown loblolly pine
Author(s) -
BASSIRIRAD H.,
THOMAS R. B.,
REYNOLDS J. F.,
STRAIN B. R.
Publication year - 1996
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1996.tb00260.x
Subject(s) - nitrogen , ecosystem , atmosphere (unit) , chemistry , temperate climate , environmental chemistry , environmental science , atmospheric sciences , botany , ecology , biology , physics , meteorology , organic chemistry
The nitrogen requirement of plants is predominantly supplied by NH 4 + and/or NO 3 − from the soil solution, but the energetic cost of uptake and assimilation is generally higher for NO 3 − than for NH 4 + . We found that CO 2 enrichment of the atmosphere enhanced the root uptake capacity for NO 3 − , but not for NH 4 + , in field‐grown loblolly pine saplings. Increased preference for NO 3 − at the elevated CO 2 concentration was accompanied by increased carbohydrate levels in roots. The results have important implications for the potential consequences of global climate change on plant‐and ecosystem‐level processes in many temperate forest ecosystems.