DOI: 10.5061/dryad.g79cnp635
title: Tree functional trait variation along the vertical canopy profile in central Amazonian forests

description: We quantified annual growth rates in terms of above-ground biomass (AGB),
 the maximum efficiency of photosystem II (Fv/Fm) and six tree functional
 traits related to water transport (xylem density and Huber value), leaf
 morphology (leaf size, angle, and stomatal density), and photosynthesis
 (specific leaf area) along the vertical forest profile in an old-growth
 central Amazonian forest. To investigate the influence of canopy
 environments and ontogenetic stages on the variation of these traits, we
 divided the forest into three vertical strata defined by height from the
 ground (S1: 0-20 m; S2: 20-40 m; S3: &gt;40 m). We sampled 162
 branches and 486 leaves from 54 trees of 10 species, encompassing at least
 five of the most abundant species per stratum. Path analysis and
 correlation matrices were used to explore the links between canopy
 environments, traits and the “fast-slow” plant economics spectrum.
description: The research was conducted at an old-growth forest site located
 in the Tapajós National Forest (TNF), known as K67 (02°51′S, 54°58′W),
 south of the city of Santarém (Pará, Brazil). It is an evergreen tropical
 forest on a well-drained infertile oxisol plateau with an average canopy
 height of ~40 m (Hutyra et al., 2007). At this field site, where the mean
 canopy height ranges from approximately 40 to 45 m and a sub-canopy layer
 spans 15 to 30 m (mean ≈ 28 m) (Hutyra et al., 2007; Hunter et al., 2015),
 20 ha of permanent plots have been surveyed in most years since 1999 (Pyle
 et al., 2008). Individual leaf-level sampling approach
 employed advanced tree climbing techniques to access different canopy
 levels and measure functional traits, including leaf-chlorophyll
 fluorescence with the MultispeQ.
description: # Tree functional trait variation along the vertical canopy profile in
 central Amazonian forests Dataset DOI:
 [10.5061/dryad.g79cnp635](10.5061/dryad.g79cnp635) ## Description of the
 data and file structure This README.txt file was generated on 2025-08-10
 by Leonardo Ziccardi GENERAL INFORMATION 1\. Title of Dataset: Trait
 coordination reveals the fast-slow plant economics spectrum along the
 vertical canopy profile in central Amazonian forests 2\. Author
 Information ``` A. Principal Investigator Contact Information Name: Scott
 Stark Institution: Michigan State University (MSU)
 Email:scott.c.stark@gmail.com@gmail.com B. Associate or Co-investigator
 Contact Information Name: Leonardo Ziccardi Institution: Michigan State
 University (MSU) Email: leonardo.g.ziccardi@gmail.com ``` 3\. Date of data
 collection: Between August and November (dry season months) of 2019 and
 2021. 4\. Geographic location of data collection: The data were collected
 at the Tapajós National Forest (TNF) site, located near km 67 (K67,
 02°51′S, 54°58′W) of the Santarém-Cuiabá highway, south of the city of
 Santarém (Pará, Brazil). 5\. Information about funding sources that
 supported the collection of the data: NASA FINESST grant (80NSSC24K0020)
 and the National Science Foundation (NSF) awards (grant numbers 1754357
 and 1950080). SHARING/ACCESS INFORMATION 1\. Licenses/restrictions placed
 on the data: The data provided here is freely available and we encourage
 its use. Please acknowledge the data source through a citation or in the
 acknowledgments. 2\. Links to publications that cite or use the data:
 "Trait coordination reveals the fast-slow plant economics spectrum
 along the vertical canopy profile in central Amazonian forests" -
 Ziccardi et al., 2025 METHODOLOGICAL INFORMATION 1\. Description of
 methods used for collection/generation of data: See in "Trait
 coordination reveals the fast-slow plant economics spectrum along the
 vertical canopy profile in central Amazonian forests" - Ziccardi et
 al., 2025 2\. Methods for processing the data: Data were pre-processed
 from the collected dataset using R. 3\. People involved with sample
 collection, processing, analysis and/or submission: \- Leonardo Ziccardi
 \- Scott Stark ### Files and variables #### File:
 Ziccardi_et_al_FE_2025.csv **Description:**  1\. Number of variables: 16
 2\. Number of cases/rows: 162 ##### Variables * Tree: Individual tree ID *
 Branch: Position of sampled branch in the crown (A = lower; B = middle; C
 = upper) * Scientific_name: Scientific name * Canopy_strata: Canopy strata
 define by height above ground level (S1 = 0 - 20 m; S2 = 20 - 40 m; S3 =
 &gt; 40 m) * SLA: Specific leaf area (leaf area per unit leaf dry mass, m²
 kg-1)  * Leaf_angle: Leaf angle (º) * Leaf_size: Leaf size in area terms
 (cm²) * Xylem_density: Xylem density measured at each 1-m long collected
 branch (g cm-³) * Huber_value: Huber value measured at each 1-m long
 collected branch (m² m-²) * Stomatal_density: Stomatal density (stomata
 cm-²) * Stomatal_lenght: Stomatal pore length (excluding guard cells) (µm)
 * Fv_Fm: Quantum efficiency of photosystem II * Annual_growth_AGB: The
 annual increments of above-ground biomass (AGB) (% AGB year-1) *
 DBH: Diameter at the breast height (cm) * Canopy_openness: Fraction of
 canopy openness (%) * Height: Height above the ground level (m) ## Access
 information Other publicly accessible locations of the data: * None Data
 was derived from the following sources: * None