DOI: 10.5061/dryad.2ngf1vj0d
title: Data from: A dominant plant species and insects interactively shape plant community structure and an ecosystem function

description: Dominant plants and insects both structure plant communities and determine
 key ecosystem functions. However, dominant plants and insects can have
 opposing effects on plant community structure and ecosystem function.
 Critically, few studies have assessed the combined effects of these two
 drivers of plant community structure and ecosystem function. In this
 study, we factorially manipulated the presence of the dominant plant
 species Solidago canadensis (Canada goldenrod) and insects in an old field
 to quantify their independent and interactive effects on the plant
 community. Insect presence mediated the effects of S. canadensis removal
 on plant biomass and richness. Total plant biomass was ~32% lower
 following S. canadensis removal only when insects were present. In
 contrast, subdominant plant biomass was ~75% higher following S.
 canadensis removal, but only when insects were reduced. Subdominant
 species richness was ~37% higher following S. canadensis removal when
 insects were present, though the abundance of most subdominant species did
 not vary systematically with S. canadensis removal or insect reduction.
 Light availability was ~49% higher following S. canadensis removal with no
 effect of insect presence on light availability. Our results emphasize the
 interactive role of dominant plants and insects in determining the
 diversity and biomass of plant communities.
description: # A dominant plant species and insects interactively shape plant community
 structure and an ecosystem function
 [https://doi.org/10.5061/dryad.2ngf1vj0d](https://doi.org/10.5061/dryad.2ngf1vj0d) ## Description of the data and file structure We conducted a full factorial experiment where we manipulated the presence of the dominant plant species *Solidago canadensis* (Canada goldenrod) and insect herbivores in an old-field ecosystem in Michigan. We established 24 5 × 5 meter plots that were at least one meter apart. Within each 5 × 5 meter plot, we manipulated *S. canadensis* presence in two 1 × 1 meter subplots at two levels: (1) *S. canadensis* removal and (2) undisturbed control. In *S. canadensis* removal subplots, we removed *S. canadensis* stems by clipping all stems at the soil level. In undisturbed control subplots, we did not remove any plant biomass. We additionally established one 1 × 1-meter random biomass removal subplot within each 5 × 5-meter plot, wherein we removed the same amount of plant biomass that we removed in *S. canadensis* removal subplots, but we removed plants in a non-species-specific manner to account for potential removal induced bias in our results. We manipulated insect presence at two levels: (1) insects reduced and (2) insects present. We reduced insects from May to August 2023 in 12 of the 5 × 5 meter plots by spraying lambda-cyhalothrin insecticide every three weeks at a rate of 0.002 L per 1 × 1 meter with a backpack sprayer. In the other 12 5 × 5 meter plots where insects were present, we sprayed an equivalent amount of water at the same time as insecticide applications. At the end of the growing season in August 2023, we measured plant species richness, plant biomass, species percent cover, and light availability.  ### Files and variables #### File: ECOSPHERE\_2023\_8\_SolidagoProject\_MASTER.csv **Description:** This file contains the raw data collected in the old-field at the Matthaei Botanical Gardens during the end of August 2023 in Ann Arbor, Michigan. Field work was completed by Julia Eckberg ([eckbergj@umich.edu](mailto:eckbergj@umich.edu)). Lab work (plant biomass drying/weighing) was completed by Julia Eckberg and Lucas Lapointe at the University of Michigan. ##### Variables * Plot: ID of the plot sampled at the Matthaei Botanical Gardens. 24 plots total (each 5-m2), divided into 3 blocks (the first number) with 8 plots per block (second number). For example, plot 1.1 is the first plot in the first block. Plots at the field site are delineated with PVC pipe, with a label attached to the pipe at the southwest corner. * Removal_treatment: Biomass removal treatment that data was collected from within each Plot. “Control” subplots are untouched and all stems of the dominant plant species Solidago canadensis are removed in “SolRemoval” subplots. In “RandomBiomassRemoval” subplots the same amount of plant biomass is removed as in the “SolRemoval” subplots, but species are removed randomly. Subplots are 1-m2. “Control” subplots are in the SE corner, “SolRemoval” subplots are in the NE corner, and “RandomBiomassRemoval” subplots are in the SW corner of each 5-m2 Plot. Removal treatments were maintained throughout the growing season by returning to each subplot every three weeks from May to August and checking for any growing S. canadensis stems. Each subplot is 1-m2**.** * Insecticide_treatment:  Indicates whether or not a particular Plot was sprayed with insecticide. “Insecticide” indicates that Plot, including each removal treatment subplot within a Plot, was sprayed every three weeks with insecticide from May to August. “No_insecticide” indicates that Plot was sprayed with water during the growing season**.**  * bag_shrub_g: The total biomass (units: grams) of shrub species in each plot including bag weight. All shrubs were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot.  * shrub_g: The total biomass (units: grams) of shrub species in each plot. All shrubs were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot. * bag_forb_g: The total biomass (units: grams) of all forb species in each plot including bag weight. All forbs were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot.  * forb_g: The total biomass (units: grams) of all forb species in each plot. All forbs were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot.  * bag_grass_g: The total biomass (units: grams) of grass species in each plot including bag weight. All grasses were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot.  * grass_g: The total biomass (units: grams) of grass species in each plot. All grasses were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot. * bag_solidago_g: The total biomass (units: grams) of *Solidago canadensis* in each plot. All *S. canadensis* stems were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot.  * solidago_g: The total biomass (units: grams) of *Solidago canadensis* in each plot. All S. canadensis stems were placed in a paper bag after being cut, dried for at least 48 hours and weighed. Plant biomass was collected in a 50x20cm section in the margin of each subplot. * total_biomass_g: The total plant biomass (units: grams) of all plant species in each plot, excluding bag weight. Five empty paper bags were dried, weighed, and an average bag weight was calculated and subtracted from the raw dry biomass value to account for bag weight. This includes *S. canadensis* biomass**.**  * subdominant_biomass_g: The total subdominant plant biomass (units: grams) of all plant species in each plot, excluding bag weight. Five empty paper bags were dried, weighed, and an average bag weight was calculated and subtracted from the raw dry biomass value to account for bag weight. This does not include *S. canadensis* biomass. * bag_230524_biomass_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on May24th, 2023 including bag weight.  * biomass__230524_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on May 24th, 2023. * bag_230615_biomass_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on June 15th, 2023 including bag weight. * biomass_230615_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on June 15th, 2023. * bag_230707_biomass_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on July 7th, 2023 including bag weight. * biomass_230707_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on July 7th, 2023. * bag_230727_biomass_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on July 27th, 2023 including bag weight. * biomass_230727_removed: The amount of plant biomass removed from “SolRemoval” or “RandomBiomassRemoval” subplots on July 27th, 2023. * total_biomass_removed: Total plant biomass removed from biomass removal treatments (“SolRemoval” and “RandomBiomassRemoval”) throughout the growing season. We removed biomass from these subplots biweekly from May-August to maintain removal treatments. The total amount of plant biomass removed from these plots is indicated here.  * above_light_1: First measure of light intensity (units: lux) above the plant growth at each of the plots. Light intensity was measured using the Lux Light Meter Pro app for iPhones.  - above_light_2: Second measure of light intensity (units: lux) above the plant growth at each of the plots. Light intensity was measured using the Lux Light Meter Pro app for iPhones.  - above_light_3: Third measure of light intensity (units: lux) above the plant growth at each of the plots. Light intensity was measured using the Lux Light Meter Pro app for iPhones.  - mean_above_light: Average measure of light intensity (units: lux) above the plant growth at each of the plots. Light intensity was measured using the Lux Light Meter Pro app for iPhones.  - below_light_1: First measure of light intensity (units: lux) within the understory. Measurements were taken about 20 cm above the ground.  - below_light_2: Second measure of light intensity (units: lux) within the understory. Measurements were taken about 20 cm above the ground.  - below_light_3: Third measure of light intensity (units: lux) within the understory. Measurements were taken about 20 cm above the ground.  - mean_below_light: Average measure of light intensity (units: lux) within the understory. 3 light intensity measurements were taken at each plot and averaged. - light_availability: The proportion of above light that made it into the understory. Calculated by dividing the “mean_above_light” by “mean_below_light” measurements for each plot.  * august_species_richness: Plant species richness in August 2023.  * achmil_cover: Cover of *Achillea millefolium* (unit: percent) found in each subplot * apocan_cover: Cover of *Apocynum cannabinum* (unit: percent) found in each subplot * ascsyr_cover: Cover of *Asclepias syriaca* (unit: percent) found in each subplot * asppla_cover: Cover of *Asplenium platyneuron* (unit: percent) found in each subplot * aster4_cover: Cover of *Digitalis grandiflora (unit: percent) found in each subplot* * aster5_cover: Cover of an unknown aster species (unit: percent) found in each subplot * caraca_cover: Cover of *Carduus acanthoides* (unit: percent) found in each subplot * carexs_cover: Cover of an unknown *Carex sp.* (unit: percent) found in each subplot * cerarv_cover: Cover of *Cersium arvense* (unit: percent) found in each subplot * cerfon_cover: Cover of *Cerastium fontanum* (unit: percent) found in each subplot * clover_cover: Cover of *Trifolium repens* (unit: percent) found in each subplot * corrac_cover: Cover of *Cornus racemosa* (unit: percent) found in each subplot * daucar_cover: Cover of *Daucus carota* (unit: percent) found in each subplot * erican_cover: Cover of *Erigeron canadensis* (unit: percent) found in each subplot * eristr_cover: Cover of *Erigeron strigosus* (unit: percent) found in each subplot * eutgra_cover: Cover of *Euthamia graminifolia (unit: percent) found in each subplot* * fatgra_cover: Cover of an unidentified grass (unit: percent) found in each subplot * fesrub_cover: Cover of *Festuca rubra (unit: percent) found in each subplot* * fraaln_cover: Cover of *Frangula alnus* (unit: percent) found in each subplot * fraame_cover: Cover of *Fraxinus americana* (unit: percent) found in each subplot * fravir_cover: Cover of *Fragaria virginiana* (unit: percent) found in each subplot * galtri_cover: Cover of *Galium triflorum* (unit: percent) found in each subplot * galver_cover: Cover of *Galium verum* (unit: percent) found in each subplot * geumac_cover: Cover of *Geum macrophyllum* (unit: percent) found in each subplot * geumale_cover: Cover of *Geum aleppicum* (unit: percent) found in each subplot * grass5_cover: Cover of an unknown grass species (unit: percent) found in each subplot * hacvir_cover: Cover of *Hackelia virginiana* (unit: percent) found in each subplot * honeys_cover: Cover of *Lonicera morrowii (unit: percent) found in each subplot* * hypper_cover: Cover of *Hypericum perforatum* (unit: percent) found in each subplot * laccan_cover: Cover of *Lactuca canadensis (unit: percent) found in each subplot* * leuvul_cover: Cover of *Leucanthemum vulgare* (unit: percent) found in each subplot * linvul_cover: Cover of *Linaria vulgaris* (unit: percent) found in each subplot * malspp_cover: Cover of *Malus fusca* (unit: percent) found in each subplot * monfis_cover: Cover of *Monarda fistulosa (unit: percent) found in each subplot* * moralb_cover: Cover of *Morus alba* (unit: percent) found in each subplot * nigdam_cover: Cover of *Nigella damascena* (unit: percent) found in each subplot * orivul_cover: Cover of *Origanum vulgare* (unit: percent) found in each subplot * pangra_cover: Cover of *Panicum dichotomiflorum (unit: percent) found in each subplot* * parqui_cover: Cover of *Parthenocissus quinquefolia* (unit: percent) found in each subplot * pillon_cover: Cover of *Pilosella longifolia* (unit: percent) found in each subplot * poapra_cover: Cover of *Poa pratensis* (unit: percent) found in each subplot * poplar_cover: Cover of *Populus sp.* (unit: percent) found in each subplot * potrec_cover: Cover of *Potentilla recta* (unit: percent) found in each subplot * pruser_cover: Cover of *Prunus serotina* (unit: percent) found in each subplot * ratpin_cover: Cover of *Ratibida pinnata* (unit: percent) found in each subplot * rhacat_cover: Cover of *Rhamnus cathartica* (unit: percent) found in each subplot * rosbla_cover: Cover of *Rosa blanda* (unit: percent) found in each subplot * rubocc_cover: Cover of *Rubus occidentalis* (unit: percent) found in each subplot * rudhir_cover: Cover of *Rudbeckia hirta* (unit: percent) found in each subplot * rumace_cover: Cover of *Rumex acetosella* (unit: percent) found in each subplot * rumcri_cover: Cover of *Rumex crispus* (unit: percent) found in each subplot * solcan_cover: Cover of *Solidago canadensis (unit: percent) found in each subplot* * sornut_cover: Cover of *Sorghastrum nutans* (unit: percent) found in each subplot * symlat_cover: Cover of *Symphyotrichum lateriflorum* (unit: percent) found in each subplot * symdru_cover: Cover of *Symphyotrichum drummondii* (unit: percent) found in each subplot * symool_cover: Cover of *Symphyotrichum oolentangiense* (unit: percent) found in each subplot * symspp_cover: Cover of an unknown *Symphyotrichum sp. (unit: percent) found in each subplot* * tanvul_cover: Cover of *Tanacetum vulgare* (unit: percent) found in each subplot * taroff_cover: Cover of *Taraxacum officinale* (unit: percent) found in each subplot * thapub_cover: Cover of *Thalictrum pubescens* (unit: percent) found in each subplot * torili_cover: Cover of an unknown *Torilis sp*. (unit: percent) found in each subplot * toxryd_cover: Cover of *Toxicodendron rydbergii* (unit: percent) found in each subplot * ulmame_cover: Cover of *Ulmus americana* (unit: percent) found in each subplot * victet_cover: Cover of *Vicia tetrasperma* (unit: percent) found in each subplot * vitrip_cover: Cover of *Vitis riparia* (unit: percent) found in each subplot * Notes: Any notes related to aspects of the data.  ## Code/software We used R version 4.1.3 to view, organize, and analyze our data. We used the *"stats"* package to calculate log response ratios and the *"ggplot2"* package to visualize data.  Reference:  R Core Team. *R: A Language and Environment for Statistical Computing*. R Foundation for Statistical Computing (2022).