DOI: 10.5061/dryad.5x69p8dck
title: Data from: Mycorrhizal-herbivore interactions and the competitive release of subdominant tallgrass prairie species

description: Plant-microbial-herbivore interactions play a crucial role in the
 structuring and maintenance of plant communities and biodiversity, yet
 these relationships are complex. In grassland ecosystems, herbivores have
 the potential to greatly influence the survival, growth, and reproduction
 of plants. However, few studies examine interactions of above- and
 belowground grazing and AM mycorrhizal symbiosis on plant community
 structure. We established experimental mesocosms containing an
 assemblage of eight tallgrass prairie grass and forb species in native
 prairie soil, maintained under mycorrhizal and nonmycorrhizal conditions,
 with and without native herbivorous soil nematodes, and with and without
 grasshopper herbivory. Using factorial analysis of variance and principal
 component analysis, we examined: a) the independent and interacting
 effects of above- and belowground herbivores on AM symbiosis in tallgrass
 prairie mesocosms, b) independent and interacting effects of above- and
 belowground herbivores and mycorrhizal fungi on plant community structure,
 and c) potential influences of mycorrhizal responsiveness of host plants
 on herbivory tolerance, and concomitant shifts in plant community
 composition. Treatment effects were characterized by interactions
 between AM fungi and both aboveground and belowground herbivores, while
 herbivore effects were additive. The dominance of mycorrhizal-dependent C4
 grasses in the presence of AMF symbiosis was increased (p &lt; 0.0001)
 by grasshopper herbivory but reduced (p &lt; 0.0001) by nematode
 herbivory. Cool-season C3 grasses exhibited a competitive release in the
 absence of AMF symbiosis but this effect was largely reversed in the
 presence of grasshopper herbivory. Forbs showed species-specific responses
 to both AM fungal inoculation and the addition of herbivores. Biomass of
 the grazing-avoidant, facultatively mycotrophic forb Brickellia
 eupatorioides increased (p &lt; 0.0001) in the absence of AMF
 symbiosis and with grasshopper herbivory, while AMF-related increases in
 the aboveground biomass of mycorrhizal-dependent forbs Rudbeckia
 hirta and Salvia azurea were eradicated (p &lt; 0.0001) by grasshopper
 herbivory. In contrast, nematode herbivory enhanced (p = 0.001) the
 contribution of Salvia azurea to total biomass. Synthesis: Our research
 indicates that AM symbiosis is the key driver of the dominance of C4
 grasses in the tallgrass prairie, with foliar and root herbivory being two
 mechanisms for the maintenance of plant diversity.
description: Experimental tallgrass prairie plant communities were constructed
 and maintained in large mesocosms grown in a greenhouse facility at Kansas
 State University in Manhattan, KS, USA. Data collected includes
 end-of-season biomass production and colonization of roots by AM
 fungi.
description: # Mycorrhizal-herbivore interactions and the competitive release of
 subdominant tallgrass prairie species
 [https://doi.org/10.5061/dryad.5x69p8dck](https://doi.org/10.5061/dryad.5x69p8dck) We have submitted our raw data for total above- and belowground biomass (abv_blw_biomass.csv), species-specific biomass (biomass.csv), and AM fungal colonization raw AM_colonization.csv). ## Description of the data and file structure Data is constructed and represented as simple .csv files. Specific abbreviations and codes for each of the three .csv files can be seen below: **abv_blw_biomass.csv** Cosm#: Mesocosm unique ID Mycorrhizal: AM fungal treatment (Myc: inoculated with AM fungi; Non-myc: non-inoculated) Nematode: Nematode treatment (yes: inoculated with AM fungi; no: non-inoculated) Grasshopper: Grasshopper treatment (yes.ghop: grasshoppers introduced to mesocosm; no.ghop: grasshoppers absent) Replicate: Treatment combination-specific replicate number (1 thru 8) ABV: Aboveground biomass (stem + leaves + inflorescence) of entire mesocosm in grams BLW: Belowground biomass (roots + rhizomes) of entire mesocosm in grams TOT: Sum of ABV + BLW s/r ratio: Shoot:root ratio (i.e. shoot/root) **biomass.csv** species: Abbreviated species ID (Ag = Andropogon gerardii; Sn = Sorghastrum nutans; Ec = Elymus canadensis; Ps = Pascopyrum smithii; Be = Brickellia eupatorioides; Rh = Rudbeckia hirta; Sa = Salvia azurea; Lc = Lespedeza cappitata myc: AM fungal treatment (myc: inoculated with AM fungi; nonmyc: non-inoculated) nem: Nematode treatment (yes.nem: inoculated with AM fungi; no: non-inoculated) ghop: Grasshopper treatment (yes.ghop: grasshoppers introduced to mesocosm; no.ghop: grasshoppers absent) dry weight: species-specific aboveground biomass (stem + leaves + inflorescence) within a mesocosm **AM_colonization.csv** myc: AM fungal treatment (Myc: inoculated with AM fungi); only mesocosms inoculated with AM fungi were scored and recorded (a small subset of non-AM mesocosms were checked to confirm lack of colonization) ghop: Grasshopper treatment (yes: grasshoppers introduced to mesocosm; no: grasshoppers absent) nem: Nematode treatment (yes: inoculated with AM fungi; no: non-inoculated) col: raw AM fungal colonization values on a scale from 1-100 p.col: transformed proportional colonization values (0-1) **Code/Software** All analyses were conducted R v4.1.0 using base R and package 'emmeans' (Lenth, 2021).