DOI: 10.5061/dryad.2rbnzs7zz
title: Data from: Herbivory resistance in dwarf shrubs combines with simulated warming to shift phenology and decrease reproduction

description: Research focus on the phenology of plants has accompanied current trends
 in climate warming, because the two are inextricably linked. Warmer
 temperatures have led to advanced plant phenology in a range of systems,
 although some responses are species specific. However, other stressors,
 such as herbivory, can delay or advance plant phenology, and few studies
 have addressed the combined impact of these drivers. We experimentally
 warmed plots with open top chambers (OTCs) and simulated herbivory
 resistance to insect outbreaks with Methyl jasmonate (MeJA), along an
 elevational climatic gradient. We then recorded vegetative and
 reproductive phenology in two functionally important dwarf shrubs, the
 deciduous Vaccinium myrtillus (bilberry) and the evergreen V. vitis-idaea
 (lingonberry), to test the responses to the combined treatments. Based on
 earlier findings, we expected larger phenological responses at higher
 elevations and for bilberry. We found that in the year after MeJA
 application, both bilberry and lingonberry delayed vegetative and
 reproductive phenology, although responses were stronger in bilberry.
 Warming with OTCs weakly advanced phenology in both species, but combined
 effects were not consistent. We further examined the consequences of this
 altered phenology on reproductive output with multigroup piecewise
 structural equation modelling and found that herbivory resistance driven
 changes to phenology had a strong mediating effect on berry numbers,
 particularly under warmed conditions and mainly in the year after MeJA
 application. Synthesis: These results demonstrate the need to consider
 combined pressures in understanding the impacts of global change on plants
 and highlight that multiple drivers may have unidentified synergetic
 effects on species phenology and reproduction.
description: # Herbivory resistance in dwarf shrubs combines with simulated warming to
 shift phenology and decrease reproduction
 [https://doi.org/10.5061/dryad.2rbnzs7zz](https://doi.org/10.5061/dryad.2rbnzs7zz) ## Description of the data and file structure This dataset contains two sheets - one for Vaccinium myrtillus (bilberry) and one for Vaccinium vitis-idaea (lingonberry). The data for both sheets come from a field experiment conducted between 2017 and 2019. There were 3 field sites (Low, Mid and High), each of which have 6 blocks (A to F). Within each block there are four plots (1-4), and each plot was given one of 4 treatments: 1) warming only with OTC, 2) warming and "resistance" treatment (sprayed with Methyl jasmonate in 2016), 3) Resistance only, 4) no OTC or resistance (control). Within each plot, we counted flowers regularly to provide plot level phenology data on flowering. Also, we followed 4 ramets in each plot to provide mean plot level phenology data on vegetative stages. Also included are maximum (peak) number of flowers and berries per plot. The metadata sheet describe the headings for both plant sheets. ### Files and variables #### File: Data\_for\_Gillespie\_and\_Hegland.xlsx **Description:** An excel file containing plot information and all phenology variables used in the study ##### Variables * All variables are defined in the metadata sheet        Missing data: NA ## Code/software MS Excel can be used to view the file