DOI: 10.5061/dryad.ksn02v7fb
title: Assessing non-reproductive labour in Platycerium bifurcatum

description: In complex animal societies, group members often sub-divide labor by
 focusing on different tasks such as reproduction and defense. While
 division of labor is well documented in animals, little is known about
 whether colonial plants exhibit similar patterns in task differentiation.
 To help bridge this gap in our understanding of sociality, we investigated
 non-reproductive division of labor in the staghorn fern (Platycerium
 bifurcatum, Polypodiaceae), an epiphyte that forms colonies of many
 individual plants, which coalesce into a communal water and nutrient
 store. We conducted a series of field observations and glasshouse
 experiments to answer three questions: 1) Are individuals in the upper
 regions of colonies shaped in ways that facilitate the capture of airborne
 particulate matter (e.g., leaf-litter)? 2) Do individuals at the apex of
 colonies decay in ways that inhibit the invasion of colonies by other
 plant species? 3) Does the anatomy of fronds at the bottom of colonies
 facilitate water storage? Results show that individuals at the top of
 colonies were larger and more lobed, which fostered the retention of leaf
 litter within communal nests. Plants located at the top of colonies also
 repetitively collapsed over the upper surface of nests as they decayed,
 inhibiting the germination and growth of foreign plant species. Lastly,
 individuals at the bottom of colonies produced thicker fronds with larger
 intra-cellular spaces, which facilitated the storage of rainwater captured
 above. Overall results demonstrate clear patterns in non-reproductive
 division of labor within staghorn fern colonies that are similar to highly
 social animals.
description: # Assessing non-reproductive labour in Platycerium bifurcatum
 [https://doi.org/10.5061/dryad.ksn02v7fb](https://doi.org/10.5061/dryad.ksn02v7fb) ## Description of the data and file structure This dataset accompanies a study investigating non-reproductive labour in the staghorn fern, *Platycerium bifurcatum*. The data span field measurements and glasshouse experiments, assessing frond morphology, frond orientation, and leaflitter entrapment. These traits were analyzed to evaluate the potential roles of non-reproductive (nest) fronds in colony structure and function. The variables frond size, shape, moisture (water content), and orientation were collected in the field on wild colonies. The variable leaf dislodgement was a glasshouse experiment.  ### Files and variables Colony ID is a factor present in all data files and represents sample size for that field or laboratory experiment, and was not directly used in analyses. ### **File: `Dislodgement.`csv** **Purpose:**\ Contains data from a glasshouse experiment that tested frond resistance to dislodgement (e.g., wind force). The goal was to evaluate whether intact nest fronds contribute to litterfall entrapment. **Variables:** **Independent variable:** * Treatment (intact vs. removed fronds) **Dependent variable:** * Average wind speed (km/h) required for dislodgement **Covariates:**  * 3 leaf types provided by 3 tree species * **Legend for the three tree species used for analysis** - *Coprosma repens* = CR, *Dodonea viscosa =* DV, *Myoporum laetum* = ML * **SD of average windspeed**– Standard deviation of wind speed measurements * **SE of average windspeed** – Standard error of the mean wind speed, calculated as SD/√n * Colony ID: Representation of sample size, i.e., number colonies that were measures in the glasshouse #### **File: `Orientation.`csv** **Purpose:**\ Includes field-collected data relating the angle of fronds to their position (nodes) within a colony. Used to assess whether frond orientation is consistent across wild colonies. **Variables:** **Independent variable:** * Node number or position of frond emergence along the rhizome axis. **Dependent variable:** * Orientation of the frond: Measured vertically in degrees (0–180°). **Covariate:** * Colony ID: Representation of sample size, i.e., number colonies that were measures in the field #### **File: `Morphology.`csv** **Purpose:**\ Contains morphological measurements from 24 wild colonies. The data were used to test whether frond shape, size, and moisture content vary systematically within and between colonies. **Variables:** **Independent variable:** * Colony level: Frond position, which was an categorical indicator of frond location within the colony e.g., Lower sections, Mid sections, Higher sections of colonies **Dependent variables:** * Frond surface area: Measured via image analysis (cm) * Frond lobing: Quantitative index used to assess the extent to which the margins of the frond are indented, measured via image analysis) * Frond moisture content: Level of water saturation within a single frond **Covariates:** * Colony size: Number of ramets present in a colony * Colony ID: Representation of sample size, i.e., number colonies that were measures in the field ## Code/software Variables frond surface area and frond lobing located in the Morhology.csv dataset were obtained with ImageJ (version 1.41) All data was analyzed in RStudio (ver 2023.09.0)