Transpiration modulates phosphorus acquisition in tropical tree seedlings |
| |
Authors: | Cernusak Lucas A Winter Klaus Turner Benjamin L |
| |
Institution: | Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia. lucas.cernusak@anu.edu.au |
| |
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 H(2)O transpired g(-1) C incorporated into plant biomass, and leaf P:C as mg P g(-1) C. Leaf P:C was positively correlated with transpiration ratio across 19 species for plants grown under similar conditions (R(2)?=?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 CO(2) concentration rises, due to decreasing transpiration ratios. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|