### Abstract

Original language | English |
---|---|

Pages (from-to) | 3735-3748 |

Number of pages | 14 |

Journal | Journal of Experimental Botany |

Volume | 61 |

Issue number | 13 |

Publication status | Published - 2010 |

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*Journal of Experimental Botany*,

*61*(13), 3735-3748.

}

*Journal of Experimental Botany*, vol. 61, no. 13, pp. 3735-3748.

**Nitrogen to phosphorous ratio of plant biomass versus soil solution in a tropical pioneer tree, Ficus insipida.** / Garrish, Valerie; Cernusak, Lucas; Winter, Klaus; Turner, Benjamin L.

Research output: Contribution to journal › Article › Research › peer-review

TY - JOUR

T1 - Nitrogen to phosphorous ratio of plant biomass versus soil solution in a tropical pioneer tree, Ficus insipida

AU - Garrish, Valerie

AU - Cernusak, Lucas

AU - Winter, Klaus

AU - Turner, Benjamin L

PY - 2010

Y1 - 2010

N2 - It is commonly assumed that the nitrogen to phosphorus (N:P) ratio of a terrestrial plant reflects the relative availability of N and P in the soil in which the plant grows. Here, this was assessed for a tropical pioneer tree, Ficus insipida. Seedlings were grown in sand and irrigated with nutrient solutions containing N:P ratios ranging from <1 to >100. The experimental design further allowed investigation of physiological responses to N and P availability. Homeostatic control over N:P ratios was stronger in leaves than in stems or roots, suggesting that N:P ratios of stems and roots are more sensitive indicators of the relative availability of N and P at a site than N:P ratios of leaves. The leaf N:P ratio at which the largest plant dry mass and highest photosynthetic rates were achieved was ?11, whereas the corresponding whole-plant N:P ratio was ?6. Plant P concentration varied as a function of transpiration rate at constant nutrient solution P concentration, possibly due to transpiration-induced variation in the mass flow of P to root surfaces. The transpiration rate varied in response to nutrient solution N concentration, but not to nutrient solution P concentration, demonstrating nutritional control over transpiration by N but not P. Water-use efficiency varied as a function of N availability, but not as a function of P availability. � 2010 The Author.

AB - It is commonly assumed that the nitrogen to phosphorus (N:P) ratio of a terrestrial plant reflects the relative availability of N and P in the soil in which the plant grows. Here, this was assessed for a tropical pioneer tree, Ficus insipida. Seedlings were grown in sand and irrigated with nutrient solutions containing N:P ratios ranging from <1 to >100. The experimental design further allowed investigation of physiological responses to N and P availability. Homeostatic control over N:P ratios was stronger in leaves than in stems or roots, suggesting that N:P ratios of stems and roots are more sensitive indicators of the relative availability of N and P at a site than N:P ratios of leaves. The leaf N:P ratio at which the largest plant dry mass and highest photosynthetic rates were achieved was ?11, whereas the corresponding whole-plant N:P ratio was ?6. Plant P concentration varied as a function of transpiration rate at constant nutrient solution P concentration, possibly due to transpiration-induced variation in the mass flow of P to root surfaces. The transpiration rate varied in response to nutrient solution N concentration, but not to nutrient solution P concentration, demonstrating nutritional control over transpiration by N but not P. Water-use efficiency varied as a function of N availability, but not as a function of P availability. � 2010 The Author.

KW - nitrogen

KW - phosphorus

KW - soil

KW - article

KW - biomass

KW - Ficus

KW - metabolism

KW - photosynthesis

KW - physiology

KW - plant leaf

KW - plant root

KW - plant stem

KW - tropic climate

KW - analysis

KW - Biomass

KW - Nitrogen

KW - Phosphorus

KW - Photosynthesis

KW - Plant Leaves

KW - Plant Roots

KW - Plant Stems

KW - Soil

KW - Tropical Climate

KW - Ficus insipida

M3 - Article

VL - 61

SP - 3735

EP - 3748

JO - Journal of Experimental Botany

JF - Journal of Experimental Botany

SN - 0022-0957

IS - 13

ER -