Transpiration modulates phosphorus acquisition in tropical tree seedlings

Date

2011

Authors

Cernusak, Lucas
Winter, Klaus
Turner, Benjamin L

Journal Title

Journal ISSN

Volume Title

Publisher

Heron Publishing

Abstract

Several experiments were conducted with tropical tree and liana seedlings in which transpiration ratio and leaf phosphorus to carbon ratio (P:C) were measured. Transpiration ratio was expressed as kg H2O transpiredg-1 C incorporated into plant biomass, and leaf P:C as mg Pg-1 C. Leaf P:C was positively correlated with transpiration ratio across 19 species for plants grown under similar conditions (R2=0.35, P<0.01, n=19). For five species in the dataset, multiple treatments were imposed to cause intra-specific variation in transpiration ratio. Within four of these five species, leaf P:C correlated positively with transpiration ratio. The slope and strength of the correlation varied among species. In one experiment, whole-plant P:C was measured in addition to leaf P:C. Patterns of correlation between whole-plant P:C and transpiration ratio were similar to those between leaf P:C and transpiration ratio. Together, these observations suggest that transpiration can influence the rate of P uptake from soil in tropical tree and liana seedlings. We suggest that this occurs through transport of inorganic phosphate and organic P compounds to root surfaces by transpiration-induced mass flow of the soil solution. The positive correlation between leaf P:C and transpiration ratio suggests that leaf P:C could decline in tropical forests as atmospheric CO2 concentration rises, due to decreasing transpiration ratios.

Description

Keywords

Keywords: carbon; phosphorus; bioaccumulation; biological uptake; carbon dioxide; data set; experimental study; intraspecific variation; phosphorus; phytomass; seedling; transpiration; tropical forest; vine; water use efficiency; article; evapotranspiration; metabo elevated CO 2; mass flow; phosphorus concentration; water-use efficiency

Citation

Source

Tree Physiology

Type

Journal article

Book Title

Entity type

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Restricted until

2037-12-31