DOI: 10.5061/dryad.jdfn2z3nb
title: Challenges in the early ontogeny of a mutualistic plant: Resource availability and plant defense in juvenile Cecropia ant-plants

description: Mutualistic species often must survive periods of their development
 without their mutualist partner, but we lack a clear understanding of the
 ecological mechanisms that maintain mutualisms despite these gaps in
 partnership. In ant-plant protection mutualisms, plants house ant colonies
 that deter herbivores. Yet juvenile ant-plants often lack symbiotic ant
 colonies and must withstand herbivory pressure until they are colonized by
 ants. A sapling's ability to host ants or to employ alternative
 direct defenses, such as leaf secondary metabolites, may depend on access
 to key resources, like light, soil nutrients, and water. Alternatively,
 juvenile ant-plants may receive biotic protection at little resource cost
 from generalist predators, such as spiders. We examined whether juvenile
 Cecropia trees maintained leaf defenses, and whether sapling ant and
 chemical defenses were associated with the sapling's access to
 resources. We surveyed three species of naturally occurring juvenile
 Cecropia trees across a rainfall gradient in northwest Costa Rica. We
 found that both ant defense and chemical defense were regulated by the
 availability of light, soil fertility, and water in Cecropia saplings.
 Rather than trade-off, larger saplings and saplings with more resources
 were more likely to invest in both defense strategies, whereas smaller
 saplings and saplings with less resources appeared to have little leaf
 defense. We also found that although spiders were common on such
 resource-poor, undefended saplings, spiders did not reduce herbivory. This
 study highlights the importance of resource availability in determining
 the performance of ant-plants during early ontogenetic stages.
description: This README file was generated on 2025-02-19 by Stephanie Coronado.
 **GENERAL INFORMATION** Title of Dataset: *Challenges in the early
 ontogeny of a mutualistic plant: resource availability and plant defense
 in juvenile Cecropia ant-plants* Author Information: ``` A. Principal
 Investigator Contact Information Name: EG Pringle Institution: University
 of Nevada, Reno Address: 1664 N Virginia St, Reno, NV 89557 Email:
 epringle@unr.edu B. Associate or Co-investigator Contact Information Name:
 SM Coronado Institution: University of Nevada, Reno Address: 1664 N
 Virginia St, Reno, NV 89557 Email: steph.m.coronado@gmail.com ``` Year
 (MM/YYYY) and geographic location of data collection: **06/2019 -
 08/2019** and **06/2022 - 01/2023** in **Guanacaste, Costa Rica** Funding
 sources that supported the collection of the data: University of Nevada,
 Reno Fulbright US Student Program **SHARING/ACCESS INFORMATION**
 Licenses/restrictions placed on the data: None Annual climatic water
 deficit data was derived from: 1. Northwest Knowledge Network. (2017).
 TerraClimate database. Available online at
 [https://www.climatologylab.org/terraclimate.html]() *Recommended citation
 for this dataset:* Abatzoglou, J.T., S.Z. Dobrowski, S. A. Parks, and K.
 C. Hegewisch. 2018. TerraClimate, a high-resolution global dataset of
 Monthly climate and climatic water balance from 1958-2015. Sci Data 5:
 170191. **DATA & FILE OVERVIEW** File List: 1. SeasonSums_21jun24.csv
 has: * Caterpillar, ant and spider abundances observed per tree, over the
 course of the survey * Cecropia species, site location, height, canopy
 area estimates, light availability, and herbivory estimates * Leaf traits,
 including total phenolics * Climatic water deficit and soil fertility
 index at the site level 2. Biomass\_ greenhouse \_Jan2023.csv has: * Data
 from the phytometer soil fertility experiment, including- * Sapling
 height, and dry leaf, stem and root weight **DATA-SPECIFIC INFORMATION
 FOR:** **SeasonSums_21jun24.csv** 1. Number of variables: 48 2. Number of
 cases/rows: 246 3. Variable list: * Tree_code = categorical, unique
 identified for each tree * Site = categorical, one of six sites in
 Guanacaste, Costa Rica. * San Gerardo: 10.876, -85.390 * La Perla: 10.764,
 -85.384 * Pitilla: 10.986, -85.420 * Caribe: 10.899, -85.274 * Maritza:
 10.967, -85.607 * Santa Rosa: 10.833, -85.612 * Species = categorical, one
 of three *Cecropia* tree species * C. peltata * C. obtusifolia * C.
 insignis * Ants = categorical, yes or no, * Y: colonized by *Azteca* * N:
 uncolonized * Lep_total = total caterpillar count per tree * Spiders=
 total spider count per tree * **Columns [7]-[16]** = *individual
 caterpillar species counts. Column name is species identity, when known* *
 Mean_activty = mean number of ants counted patrolling/min per tree *
 Height = tree height, cm * BD = tree basal diameter, cm * Leaves = leaf
 count per tree * CanopyEst = [Leaves] * [BD], cm^2 * Lep_density = [ Lep
 \_total ] / [BD] * Spid_density = [Spiders] / [BD] * Perc_Herbiv = percent
 estimated herbivory loss per tree * TotPhen = total leaf phenolics, in
 total peak absorbance units * Light = discrete ordinal, canopy cover index
 1-5 * SoilFertIndex = mean dried total plant biomass grown with site soil
 composites, in grams * SiteCWD = mean yearly climatic water deficit per
 site, using data from years 2009-2019, in mm * **Columns [28]-[45]** =
 *individual spider counts at the family level. Column name is spider
 family identity, when known* * Trichomes = stelae trichome abundance/ 0.79
 cm^2 * SLA = specific leaf area per tree * Leaf_force = leaf toughness per
 tree, kN 4. Missing data codes = NA **DATA-SPECIFIC INFORMATION FOR:**
 **Biomass\_ greenhouse_Jan2023.csv** 1. Number of variables: 14 2. Number
 of cases/rows: 110 3. Variable list: * Date = date seedling was
 transplanted into soil treatment * PlantID = categorical, unique number
 assigned to each seedling * Species = categorical, either C. obtusifolia
 or C. peltata * SoilSource = categorical, one of six sites from which the
 seedling's soil was collected. * GR: San Gerardo (10.876,-85.390) *
 PR: La Perla (10.764, -85.384) * PT: Pitilla (10.986, -85.420) * CB:
 Caribe (10.899, -85.274) * MR: Maritza (10.967, -85.607) * SR: Santa Rosa
 (10.833, -85.612) * Height_cm = final sapling height, measured from just
 above the soil to the top apical meristem * Leaf_area = Estimated total
 leaf area. Total leaf number multiplied by the average length * width of
 three randomly chosen leaves, in cm^2 * Leaf_wt = total dry weight of leaf
 tissue, in grams * Stem_wt = total dry weight of stem tissue, in g *
 Root_wt = total dry weight of root tissue, in g * RootShoot =
 Root-to-shoot ratio. [[Root \_wt] / ([Leaf \_wt] + [ Stem \_ wt]) * LWR =
 Leaf-weight ratio. [Leaf \_wt] / ([Root \_wt] + [Leaf \_wt] + [ Stem \_
 wt]) * SWR = Stem-weight ratio. [Stem \_wt] / ([Root \_wt] + [Leaf \_wt] +
 [ Stem \_ wt]) * SLA = Specific leaf area. Average leaf area / dry leaf
 mass, in cm^2/g * TotBiomass = [Root \_wt] + [Leaf \_wt] + [ Stem \_ wt]
 4. Missing data codes= NA **SUPPORTING SOFTWARE** File name:
 "Biotropica24_code.R" File description: R-code from which the
 statistics and figures included in the manuscript and supplementary
 materials can be derived. Data files utilized:
 "SeasonSums_21jun24.csv", "Biomass\_
 greenhouse_Jan2023.csv" Outline of contents: * Path model (Figure 1)
 * Characterizing environmental variables (Table S1) * Total phenolics glm
 (Table S2) * Phenolics x light x soil fertility partial plot (Figure 2) *
 Phenolics x cwd partial plot (Figure S3) * Phenolics x species partial
 plot (Figure S6) * Ant patrol activity glm (Table S2) * Ant activity x
 tree size x light partial plot (Figure 2) * Ant activity x cwd partial
 plot (Figure S4) * Ant activity x soil fertility partial plot (Figure S4)
 * Caterpillar density glm (Table S3) * Herbivory glm (Table S3) * Leaf
 traits and herbivory (Figure S7) * Spider density glm (Table S3) * Spider
 denisty, ant activity and herbivory (Figure 3) Required R packages: *
 tidyverse * glmmTMB * car * DHARMa * lmtest * mgcv * MuMIn * visreg * lme4
 * lavaan * ggstatsplot * lattice * equatiomatic