SLA Socratea exorrhiza

Published: 14 November 2022| Version 1 | DOI: 10.17632/bwfm57cgky.1
Gerardo Avalos


Specific leaf area predicts the total carbon content of understory individuals of the neotropical palm Socratea exorrhiza


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Data was collected in 2019 EARTH Forest Reserve, Costa Rica (10° 11' N, 84° 40' W, 30 masl). Here, Alvarez-Clare et al. (2013) established a long-term fertilization experiment in May 2007 using 24, 30x30 m square plots. The stilt-rooted canopy palm Socratea exorrhiza is found from S Nicaragua, Costa Rica, and Panama, to Colombia, Ecuador, Peru, Venezuela, Guyana, Suriname, Brazil, and Bolivia (Dransfield et al., 2008). In the Amazon, S. exorrhiza is a habitat generalist that achieves high abundance and ranks ninth among of the ten most widespread plant species (ter Steege et al., 2013). Measurement of SLA — We measured specific leaf area (SLA, cm2 g-1) from leaf samples of 112 palms varying from 0.14 to 10 m in height. The fronds of these palms were reached manually or were within the range of an extendable pole of 5 m in length. To calculate SLA, we took tissue samples of 2 cm2 from one of the central leaflets in a fully expanded, mature frond, stored them in a paper bag, and placed them in an oven for 22 h at 50°C. Once these leaf samples were dried, they were weighed on an Ohaus analytical scale with a resolution of 0.001 g (model SPX123) to determine the SLA in cm2 g-1. We examined the variation in SLA according to stem height and slenderness ratio (the ratio of stem height in m to diameter in cm, Niklas, 1994; Niklas et al., 2006) to describe strategies of growth and resource allocation in the understory. Measurement of carbon content — We estimated the total carbon content per palm (kg) using the allometric equation Ln (C) = - 2.60 + 0.34 * diameter (cm), r2 = 0.97, developed by Avalos et al. (2022b). This allometric equation was based on the harvesting of 10 individuals of S. exorrhiza on the Caribbean slope of Costa Rica ranging 1.4 to 14.8 m in height. The carbon content was estimated as the percentage of carbon (% C) of the dry weight of the biomass per individual palm measured using an automatic carbon and nitrogen analyzer (TruSpec CN; LECO Corporation). Values were converted from natural logarithms back to linear space and expressed in Kg of carbon per individual palm. Characterization of the light environment using hemispherical photographs — To characterize the light environment in the understory, we obtained 25 hemispheric photographs taken with a Nikon 8 mm fisheye lens attached to a Nikon Coolpix 5000 camera positioned in the center of each of the four internal quadrants in six plots, at 1.65 m above the ground. Photographs were taken under cloudy or overcast conditions to avoid direct light beams to affect the contrast between tree foliage and areas of open canopy. The camera was mounted on a tripod and held perpendicular to the horizon with the top of the camera pointing towards the magnetic north. Hemispheric photographs were analyzed using Gap Light Analyzer (GLA) version 2.0 (Frazer et al., 1999) to estimate canopy openness and leaf area index (LAI).


Universidad de Costa Rica


Functional Ecology, Leaf Area