SI2. Description of unpublished dataset by Slot, Rey-Sánchez, and Kitajima.
Study site and species selection
The study was conducted in Parque Natural Metropolitano (PNM, 8°590N, 79°330W), a semi-deciduous
moist tropical forest near Panama City, Republic of Panama. Annual rainfall at the site averages 1740
mm, and a distinct dry season exists from January to April. A 42-m tall canopy crane with a 51-m long jib,
maintained by the Smithsonian Tropical Research Institute, was used to access canopy leaves. Four tree
species and three liana species were selected from the upper forest canopy. Trees: Anacardium
excelsum (Bertero& Balb. ex Kunth) Skeels; Luehea seemannii Triana & Planch.; Castilla elastica var.
costaricana (Liebm.) CC. Berg), Pittoniotis trichantha Griseb. Lianas: Bonamia trichantha Hallier f.;
Stigmaphyllon lindenianum A. Juss. and Serjania mexicana (L.) Willd.
Experimental setup and measurements
Upper-canopy target leaves were fit with warming frames as described in Slot et al. (2014) and
treatment leaves were exposed to nighttime temperatures of ~3°C above those of control leaves. After
at least 8 nights of warming dark respiration was measured in situ with an LI-6400 infrared gas analyzer
(Licor, Lincoln, Nebraska) two times at different ambient temperatures during the morning. Leaves were
first measured pre-dawn after turning off the heaters, after which they were darkened with aluminum
foil. A few hours later when ambient temperature had increased by 4 or 5°C, the same leaves were remeasured. We have previously used aluminum foil to pre-darken leaves for assessment of the in situ
temperature sensitivity of leaf dark respiration, and this method works well (Slot et al. 2013). This
approach enabled us to calculate the temperature sensitivity of dark respiration (Q10; the proportional
increase in respiration with 10°C warming) and use this to standardize respiration rates to a set
temperature of 25°C (R25). Acclimation was assessed as AcclimSetTemp=R25 control/R25 warmed where species
averages of R25 are used to calculate a single AcclimSetTemp value per species.
Results
Species
Anacardium excelsum
Castilla elastica
Luehea seemannii
Pittoniotis trichantha
Bonamia trichantra
Serjania mexicana
Stigmaphyllon
lindenianum
Growth
form
Tree
Tree
Tree
Tree
Liana
Liana
Liana
Leaf habit
Broadleaf evergreen
Broadleaf deciduous
Broadleaf deciduous
Broadleaf deciduous
Broadleaf evergreen
Broadleaf deciduous
Broadleaf deciduous
R25 Control
(µmol m-2s-1)
0.74
0.61
0.89
0.80
1.21
0.75
0.60
R25 Warmed
(µmol m-2s-1)
0.47
0.62
0.95
0.71
1.16
0.59
0.54
AcclimSetTemp
1.59
0.99
0.94
1.13
1.04
1.28
1.10
Acknowledgements
This project was funded by National Science Foundation-Integrated Organismal Systems grant 1051789.
Logistic support was provided by the Smithsonian Tropical Research Institute. We thank crane operators
Edwin Andrade and Julio Piti.
References
Slot M, Wright S J, Kitajima K (2013) Foliar respiration and its temperature sensitivity in trees and lianas:
in situ measurements in the upper canopy of a tropical forest. Tree physiol 33, 505–515. doi:
10.1093/treephys/tpt026
Slot M, Rey-Sánchez AC, Gerber S, Lichstein JW, Winter K, Kitajima K (2014) Thermal acclimation of leaf
respiration of tropical trees and lianas: response to experimental canopy warming, and consequences
for tropical forest carbon balance. Glob Change Biol 20, 2915–2926. doi: 10.1111/gcb.12563