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Family‐ and population‐level responses to atmospheric CO 2 concentration: gas exchange and the allocation of C, N, and biomass in Plantago lanceolata (Plantaginaceae)
Author(s) -
Jenkins Klus Dawn,
Kalisz Susan,
Curtis Peter S.,
Teeri James A.,
Tonsor Stephen J.
Publication year - 2001
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2657091
Subject(s) - plantago , stomatal conductance , plantaginaceae , biology , transpiration , sugar , carbon dioxide , photosynthesis , population , water use efficiency , nitrogen , botany , zoology , partial pressure , shoot , horticulture , ecology , chemistry , biochemistry , demography , organic chemistry , sociology , oxygen
To ascertain the inheritance of responses to changing atmospheric CO 2 content, we partitioned response to elevated CO 2 in Plantago lanceolata between families and populations in 18 families in two populations. Plants were grown in 35 Pa and 71 Pa partial pressure of CO 2 (pCO 2 ) in open‐top chambers. We measured above‐ and belowground mass, carbon (C), nitrogen (N), hexose sugar, and gas exchange properties in both CO 2 treatments. Families within populations differed in mass, mass allocation, root : shoot ratios, aboveground percentage N, C : N ratio, and gas exchange properties. The CO 2 × family interaction is the main indicator of potential evolutionary responses to changing CO 2 . Significant CO 2 × family interactions were observed for N content, C : N ratio, and photosynthetic rate ( A : instantaneous light‐saturated carbon assimilation capacity), intercellular CO 2 concentration, transpiration rate ( E ), and water use efficiency (WUE = A/E ), but not for stomatal conductance. Families differed significantly in acclimation across time. The ratio of A in elevated vs. ambient growth CO 2 , when measured at a common internal CO 2 partial pressure was 0.79, indicating down‐regulation of A under CO 2 enrichment. Mass, C : N ratio, percentage, C (%C), and soluble sugar all increased significantly but overall %N did not change. Increases in %C and sugar were significant and were coincident with redistribution of N aboveground. The observed variation among populations and families in response to CO 2 is evidence of genetic variation in response and therefore of the potential for novel evolutionary trajectories with rising atmospheric CO 2 .