Data from: Mycorrhizal-herbivore interactions and the competitive release of subdominant tallgrass prairie species
Data files
May 22, 2024 version files 21.93 KB
Abstract
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 < 0.0001) by grasshopper herbivory but reduced (p < 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 < 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 < 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.
README: Mycorrhizal-herbivore interactions and the competitive release of subdominant tallgrass prairie species
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).
Methods
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.