DOI: 10.5061/dryad.905qfttt8
title: Data from: Tree diversity enhances predation by birds but not by arthropods across climate gradients

description: Tree diversity can promote both predator abundance and diversity. However,
 whether this translates into increased predation and top-down control of
 herbivores across predator taxonomic groups and contrasting environmental
 conditions remains unresolved. We used a global network of tree diversity
 experiments (www.treedivnet.ugent.be; TreeDivNet) spread across three
 continents and three biomes to test the effects of tree species richness
 on predation across varying climatic conditions of temperature and
 precipitation. We recorded bird and arthropod predation attempts on
 plasticine caterpillars in monocultures and tree species mixtures. Both
 tree species richness and temperature increased predation by birds, but
 not by arthropods. Furthermore, the effects of tree species richness on
 predation were consistent across the studied climatic gradient. Our
 findings provide evidence that tree diversity strengthens top-down control
 of insect herbivores by birds, underscoring the need of implementing
 conservation strategies that safeguard tree diversity to sustain ecosystem
 services provided by natural enemies in forests.
description: The data and R (R markdown) code used in this study are included
 here.  The data file shows plot-level data for tree species richness,
 arthropod, and bird predation, alongside site-specific variables in 14
 experimental sites belonging to the TreeDivNet global network of tree
 diversity experiments.
description: # Data from: Tree diversity enhances predation by birds but not by
 arthropods across climate gradients
 [https://doi.org/10.5061/dryad.905qfttt8](https://doi.org/10.5061/dryad.905qfttt8) We used a global network of tree diversity experiments (*TreeDivNet*) spread across three continents and three biomes to test the effects of tree species richness on predation across varying climatic conditions of temperature and precipitation. We recorded bird and arthropod predation attempts on plasticine caterpillars in plots with varying levels of tree species richness, including monocultures and tree species mixtures. ## Description of the data and file structure We provide plot-level data for tree species richness, predation attempts by birds and artrhopods, as well as other plot and site-level variables. | Column: Description | | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | X: Unique Plot ID | | Experiment: Experiment name | | Site: Site within each experiment  | | Experiment2: Experimental sites considered as individual experiments in this study | | Country: Country where the experiment is located | | Continent: Continent where the experiment is located | | Biome: Biome where the experiment is located | | Lat: Latitude | | Lon: Longitude | | MeanAlt: Mean elevation (m) | | ClimDescription: Climate description  | | Year: Year when predation data was collected | | SurveyMonths: Months when surveys where performed | | Block: Block within experiment  | | PlotID: Unique plot ID | | PlotRichness: Tree species richness | | BirdDamage: Number of predation attempts identified as birds | | ArthropodDamage: Number of predation attempts identified as arthropods | | MammalDamage: Number of predation attempts identified as mamals | | ReptileDamage: Number of predation attempts identified as reptiles | | TotDamKnown: Total number of identified predation attempts | | CatDays: Caterpillar days (number of caterpillars per plot multiplied by the duration of their exposure to predators) | | No.PreyInstalled: Number of caterpillars installed per plot | | AnnTEMPmean: Annual mean temperature (ºC) | | AnnPRECmean: Annual mean precipitation (mm) | | BlockID: Unique Block ID | | logrichness: Log of tree species richness | | bird\_avoidance: Categorical factor for short (less than 7 days of exposure) vs. Long (7 or more days of exposure) periods of exposure affecting bird avoidance behaviour | | stand\_age: Stang age (in years) | ## Code/Software We analyzed the data using R software version 4.2.1 (R Core Team, 2013). The R code used to analyze this data is presented here (R Markdown).