Publication Date:
2013-05-16
Description:
Leaf dark respiration ( R ) and its temperature sensitivity are essential for efforts to model carbon fluxes in tropical forests under current and future temperature regimes, but insufficient data exist to generalize patterns of R in species-rich tropical forests. Here, we tested the hypothesis that R and its temperature sensitivity (expressed as Q 10 , the proportional increase in R with a 10 °C rise in temperature) vary in relation to leaf functional traits, and among plant functional types (PFTs). We conducted in situ measurements of R of 461 leaves of 26 species of tree and liana in the upper canopy of a tropical forest in Panama. A construction crane allowed repeated non-destructive access to measure leaves kept in the dark since the previous night and equilibrated to the ambient temperature of 23–31 °C in the morning. R at 25 °C ( R 25 ) varied among species (mean 1.11 μmol m –2 s –1 ; range 0.72–1.79 μmol m –2 s –1 ) but did not differ significantly among PFTs. R 25 correlated positively with photosynthetic capacity, leaf mass per unit area, concentrations of nitrogen and phosphorus, and negatively with leaf lifespan. Q 10 estimated for each species was on average higher than the 2.0 often assumed in coupled climate–vegetation models (mean 2.19; range 1.24–3.66). Early-successional tree species had higher Q 10 values than other functional types, but interspecific variation in Q 10 values was not correlated with other leaf traits. Similarity in respiration characteristics across PFTs, and relatively strong correlations of R with other leaf functional traits offer potential for trait-based vegetation modeling in species-rich tropical forests.
Print ISSN:
0829-318X
Electronic ISSN:
1758-4469
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Permalink