Photosynthetic parameters and nutrient content of trees at the Panama crane sites.

Author(s): Gu L; Norby R; Haworth I; Jensen A; Turner B; Walker A; Warren J; Weston D; Winter K

Dataset Information


Site Name: Parque Natural Metropolitano; Bosque Protector San Lorenzo (Fort Sherman)

Variables: Leaf chemistry; Leaf photosynthetic traits (Vcmax and Jmax)

Date Range: Jan. 22, 2013 - Jan. 31, 2013

Description: This data package contains leaf chemistry and photosynthetic traits data from trees within the NGEE Tropics Parque Natural Metropolitano (PA-PNM) and Bosque Protector San Lorenzo (PA-SLZ) sites in Panama. Photosynthetic parameters including maximum photosynthesis, Vcmax, Jmax, and TPU, were calculated from A/Ci curves. Foliar nitrogen and phosphorus concentrations and leaf mass per unit leaf area of the leaves also were determined. The plants that were sampled were classified as to species, family, order, clade, and growth form (tree, liana, perennial herb, or other). Wood density of the tree and the source of that data also are included. Included in this data package is a zip file with a single Excel data file and CSV copies.


Methods Description: Leaf gas exchange and nutrient content data were collected in January 2013 from two canopy crane sites in Panama operated by the Smithsonian Tropical Research Institute (STRI). Data for analysis of assimilation rate vs internal CO2 concentration (A/Ci) were collected with four LI-6400XT photosynthesis units from the gondola of the cranes. Fully sun-lit, mature leaves in the upper canopy of woody plants (trees and lianas) in these forests were sampled. In addition, leaves from 17 small trees and perennial herbs in the understory were measured from ground level. The A/Ci curve measurements followed the standard protocols of Long et al. (1996) and Long & Bernacchi (2003). CO2 injectors were used to control reference CO2 in typical sequences starting from a value close to ambient (e.g. 400 ppm), decreasing to a minimum value (e.g. 50 ppm), returning to the starting value (as a check point) and then increasing to a maximum value (e.g. 1500 ppm). Each curve contained at least 10 points; most had 14–16 points. When the gas exchange measurement was complete, a 373 or 423 mm2 disk was cut from the leaf with a cork borer for determination of specific leaf area (SLA) and the remaining leaf was preserved for nutrient analysis. Leaf disks and whole leaves were placed in a 70°C forced draft oven on the day of collection, dried for 2 d, leaf disks were weighed, and whole leaves were ground. Total carbon (C) and N concentrations were determined by dry combustion on a Thermo Flash 1112 Elemental Analyzer. Total P was determined by dry ashing at 550°C for 4 h, the ash dissolved in 1 M HCl and P concentrations determined by automated molybdate colorimetry on a Lachat Quikchem 8500.

Access Level: Public

Originating Institution(s): Oak Ridge National Laboratory

Sponsor Organization(s): ORNL LDRD, NGEE-Tropics

Contact: Norby, Rich - Oak Ridge National Laboratory (

Data Download

Version: 1.0

Dataset Citation: Gu L; Norby R; Haworth I; Jensen A; Turner B; Walker A; Warren J; Weston D; Winter K (2021): Photosynthetic parameters and nutrient content of trees at the Panama crane sites.. 1.0. NGEE Tropics Data Collection. (dataset).

Acknowledgement: Jorge Aranda (STRI) assisted with species identification.

Data Link: Download Dataset

NGEE Tropics data policy.


Norby, R. J., Gu, L., Haworth, I. C., Jensen, A. M., Turner, B. L., Walker, A. P., Warren, J. M., Weston, D. J., Xu, C. and Winter, K. (2016), Informing models through empirical relationships between foliar phosphorus, nitrogen and photosynthesis across diverse woody species in tropical forests of Panama. New Phytol. doi:10.1111/nph.14319