Description: This dataset is part of a research project that aims to study how liana and tree seedlings differ in terms of wood anatomy and demography in three tropical forests in Colombia.  These forests are located in the municipalities of  Cotove (Antioquia), Colorados (Bolivar) and Tyrona (Magdalena). Detailed information on the location of these forests can be found in: https://doi.org/10.1111/ele.13659 

Date: 11 June, 2024

Dataset Title: Wood anatomical traits of liana and tree seedlings from tropical dry forests

Dataset Creators: J. Puentes-Marin, A. Gonzalez-Melo & M.N. Umaña

Dataset Contact: Andres Gonzalez agonzm@umich.edu

Funding: NSF DEB-2016678 & NatGeo explorers, both granted to M.N. Umaña 

Methodological details

Study sites: Information on the location and environmental conditions of the three study sites can be found in: https://doi.org/10.1111/ele.13659 

Trait measurement:
This dataset contains measurements of eleven wood traits of 10 liana and 10 tree seedling species from tropical dry forests. Between two and six seedlings (i.e., 20-70 cm in height, and less than 1 cm in diameter) per species were collected in three mature dry forest in Colombia.

Wood density was calculated, for each stem segment, as fresh volume over dry mass. To measure wood anatomical traits, cross and tangential anatomical sections (10-15 µm thick) were cut from each stem segment using a rotary microtome with disposable blades (Leica RM2255; Leica Microsystems, Wetzlar, Germany). Anatomical sections were stained in AstraBlue (for 10 min) and Safranine O (for 10 min). Then, they were gradually dehydrated in ethanol series for 1 min each (50%, 75% and 96%), dipped in solvent and mounted on slides with Eukitt mounting medium (Electron Microscopy, Hatfield, PA, USA). Anatomical slides were photographed using a camera (Axiocam 305 color, Zeiss, Germany) mounted on a light microscope (Axio Scope A1, Zeiss).  In these anatomical photographs, we measured eleven wood anatomical traits related to transport, storage and mechanical support (See Table below). To measure the fractions (i.e., % of stem cross-sectional area) of vessels, fibers and parenchyma cells, we first manually colored each  photographs using a drawing pad (Wacon CTL-472; China) and Photoshop CS4 (Adobe Systems Incorporated, USA). Then, we calculated the fractions automatically using the batch function in the ImageJ 1.52 software (https://imagej.net/software/imagej/).  To measure fiber wall thickness (Fwt), 80 fibers per image were randomly selected and measured. Intervessel pit diameter aperture (Dpm) was measured as the horizontal pit membrane diameter at its widest point, in 20 pits per vessel and three vessels per photograph. Mean hydraulically weighted vessel diameter (Dh) was measured as: Dh= (∑ D4/n)1/4, where D is the average of the major and minor axis for each vessel cross-section, and n is the total number of vessels measured . Vessel diameter variance was calculated using the following  formula VarDh = (∑ (Di-D)²)/n-1.Where Di represents the diameter of each vessel, D is the arithmetic mean of all xylem vessel diameters, and n is the total number of xylem vessels measured.  Fwt, Dpm and Dh were measured in ImageJ.

Csv file description:

The csv file has one tab that contains scientific names, plots where the seedlings were collected, as well as species mean and standard deviation values of three bark traits and seven wood traits. 

Abbreviations	Units	Description	
WD	g/cm3	Wood density. Oven-dried mass over fress volume	
Ff	%	Fiber fraction. Percentage of stem cross-section allocated to fibers	
Vf	%	Vessel fraction. Percentage of stem cross-section allocated to vessels	
Apf	%	Axial parenchyma fraction. Percentage of stem cross-section allocated to axial parenchyma cells	
Rpf	%	Radial parenchyma fraction. Percentage of stem cross-section allocated to radial parenchyma cells	
Tpf	%	Total parenchyma fraction. Percentage of stem cross-section allocated to total (axial + radial) parenchyma cells	
Dh	𝛍m	Vessel lumen diameter. Hydraulically weighted vessel diameter	
Dpm	𝛍m	Pit membrane diameter aperture. Intervessel pit diameter aperture	
Fwt	𝛍m	Fiber wall thickness	
Vd	#	Number of vessels per square milimiter	
Vci	unitless	Variance in vessel lumen diameter