DOI: 10.5061/dryad.615q1k0
title: Data from: How do lianas and vines influence competitive differences and niche differences among tree species? Concepts and a case study in a tropical forest

description: 1. Lianas and other climbing plants are structural parasites of trees,
 generally reducing host tree survival, growth, and reproduction, yet their
 influences on the outcome of competition among tree species have remained
 largely unexplored. 2. We propose that there are three distinct components
 to liana-tree interactions: prevalence, defined as the proportion of
 infested trees; load, defined as the mean liana cover on infested trees;
 and tolerance, defined as the effect of a given level of infestation on
 tree population growth rates. We introduce a new metric that integrates
 these components, the liana burden, defined as the total effect of lianas
 on per capita population growth rates given current prevalence, load, and
 tolerance. Using these metrics, we quantify variation among 33
 co-occurring tropical tree species in liana-tree interactions and its
 relation with shade-tolerance. 3. The focal tree species vary strongly in
 liana prevalence, load, tolerance, and burden. Interspecific variation in
 tolerance is the largest contributor to interspecific variation in burden.
 Species rankings of per capita population growth rates differ depending on
 liana infestation levels. Thus, lianas alter competitive hierarchies to
 benefit tree species that are relatively tolerant of and/or resistant to
 lianas. Among tree species, shade-tolerance is positively correlated with
 liana tolerance and prevalence, but largely unrelated to load and burden,
 meaning shade-tolerance does not predict which species are competitively
 disadvantaged by lianas. We describe a variety of mechanisms by which
 lianas may potentially increase or decrease niche differences among tree
 species, including interactions with spatial and temporal environmental
 niche partitioning, and potential differences among tree species in
 relative vulnerability to different liana species. 4. Synthesis: Lianas,
 like other natural enemies, can in principle alter competitive hierarchies
 and niche structure of co-occurring tree species, and our analyses suggest
 such influences are substantial in our focal tropical tree community and
 likely many other tree communities as well. Quantifying these effects
 requires a more comprehensive approach including analyses and modeling of
 dynamics of liana-tree interactions and their variation with tree and
 liana species identities.
description: BCI tree species input
 dataData for 33 focal tree
 species on Barro Colorado Island on the proportions of trees with
 different liana cover levels, the estimated per capita population growth
 rates under different liana cover levels, and shade-tolerance indices.
 These data are an input file for the R code
 "bcispeciescalcs.r"BCIspeciesinputdata.csvR code to calculate species-level liana-tree interaction statisticsRequires species-level data on the proportions of trees in different liana cover classes, and the estimated per capita population growth rates for different liana cover classes (file BCIspeciesinputdata.csv) and data on bootstrapped sets of estimated per capita population growth rates ("BootstrappedLambdas.csv")bci_speciescalcs.RR code for conducting statistical tests presented in articleThis code calculates correlation coefficients related to figures 3, 4, 5, S3, and S5, as well as the analyses for figure S2, figure S4 and, Table S2. It requires as input the species-level liana interaction statistics file "treespstatsrelianas.csv" and the bootstrapped iterations of the key statistics "bootstraplianastats.rds" that are the output of running "bci_speciescalcs.r". See comments in the code for additional information.bci_analyses.RBootstrapped per capita population growth rates of BCI tree speciesThese are sets of bootstrapped eigenvalues generated by Visser et al. 2018 J. Ecology 106:781-794. Each row is one bootstrapped iteration. Column names denote the liana cover (l0 is liana cover 0, l1 is liana cover class 1, etc.) combined with the 6-letter species code. Note the eigenvalues are correlated across species and liana covers. These data are required by the R code "bci_speciescalcs.r"BootstrappedLambdas.csvBCI tree species statistics on tree-liana interactionsSummary statistics including confidence intervals on statistics of tree-liana interaction for the focal 33 tree species from BCI (Barro Colorado Island). This file is generated by running "bci_speciescalcs.r"treespstatsrelianas.csvLiterature data on proportion of trees infested with lianas by tree speciesStudy is a short reference to the publication; the full citations and additional information for each study are given in "litreviewsiteinfo.csv". Genus, species, and family (when available) are the taxonomic names. n is the number of trees included. prevalence is the proportion of trees infested with lianas. load is the mean proportion of the crown infested, among infested trees (see readme)litreviewalldata.csvLiterature review references and site informationInformation on country, study site, forest type, years of data collection, tree size class, data source within the publication, corresponding author name and email, and full reference for all studies included in the literature review.litreviewsiteinfo.csv