Greenhouse experiment data: Soil microbial legacies influence plant survival and growth in mine reclamation

Published Feb 25, 2026 on Dryad. https://doi.org/10.5061/dryad.7h44j0zxz

Data files

Feb 25, 2026 version files 44.93 KB

McMahen_et_al_2022_Greenhouse_Data_Dryad.csv

40.85 KB
README.md

4.08 KB

Abstract

Plants alter soil biological communities, generating ecosystem legacies that affect the performance of successive plants, influencing plant community assembly and successional trajectories. Yet, our understanding of how microbe‐mediated soil legacies influence plant establishment is limited for primary successional systems and forest ecosystems, particularly for ectomycorrhizal plants. In a two‐phase greenhouse experiment using primary successional mine reclamation materials with or without forest soil additions, we conditioned soil with an early successional shrub with low mycorrhizal dependence (willow, Salix scouleriana) and a later‐successional ectomycorrhizal conifer (spruce, Picea engelmannii × glauca). The same plant species and later‐successional plants (spruce and/or redcedar, Thuja plicata, a mid‐ to late-successional arbuscular mycorrhizal conifer) were grown as legacy‐phase seedlings in conditioned soils and unconditioned control soils. Legacy effects were evaluated based on seedling survival and biomass, and the abundance and diversity of root fungal symbionts and pathogens. We found negative intraspecific (same‐species) soil legacies for willow associated with pathogen accumulation, but neutral to positive intraspecific legacies in spruce associated with increased mycorrhizal fungal colonization and diversity. Our findings support research showing that soil legacy effects vary with plant nutrient acquisition strategy, with plants with low mycorrhizal dependence experiencing negative feedbacks and ectomycorrhizal plants experiencing positive feedbacks. Soil legacy effects of willow on next‐stage successional species (spruce and redcedar) were negative, potentially due to allelopathy, while ectomycorrhizal spruce had neutral to negative legacy effects on arbuscular mycorrhizal redcedar, likely due to the trees not associating with compatible mycorrhizae. Thus, positive biological legacies may be limited to scenarios where mycorrhizal‐dependent plants grow in soil containing legacies of compatible mycorrhizae. We found that soil legacies influenced plant performance in mine reclamation materials with and without forest soil additions, indicating that initial restoration actions may potentially exert long‐term effects on plant community composition, even in primary successional soils with low microbial activity.

Dataset DOI: 10.5061/dryad.7h44j0zxz

Description of the data and file structure

In a two-phase greenhouse experiment using primary successional mine reclamation materials with or without forest soil additions, we conditioned soil with an early successional shrub with low mycorrhizal dependence (willow, Salix scouleriana) and a later-successional ectomycorrhizal conifer (spruce, Picea engelmannii × glauca). The same plant species and later-successional plants (spruce and/or redcedar, Thuja plicata, a mid- to late-successional arbuscular mycorrhizal conifer) were grown as legacy-phase seedlings in conditioned soils and unconditioned control soils. Legacy effects were evaluated based on seedling survival and biomass, and the abundance and diversity of root fungal symbionts and pathogens.

Files and variables

File: McMahen_et_al_2022_Greenhouse_Data_Dryad.csv

Description: An Excel file containing raw data results from the greenhouse study

Variables

reclamation_material_type - growing medium seedling was grown in (no unit)
forest_soil_% - proportion of forest soil mixed with the reclamation_material_type (unit = %)
plant_species_conditioning_phase - plant species grown in the soil during the conditioning phase (no unit); "None" = control
plant_species_legacy_phase - plant species grown in the conditioned or control soil from the conditioning phase (no unit)
seedling_no - unique seeding ID (no unit); NA = seedling did not survive
germinant_survival_% - survival of germinating seeds prior to thinning (unit = %); NA = no seeds germinated and survival could not be evaluated
growing_days - number of growing days in the greenhouse (unit = # of days); NA = seedling did not survive
shoot_biomass_mg - biomass of the seeding shoot (unit = mg); NA = seedling did not survive
root_biomass_mg - biomass of the seeding root (unit = mg); NA = seedling did not survive or data point not available (n = 1)
soil_depth_from_top_of_pot - depth between soil surface and the top edge of the pot, which varied due to soil settling (unit = cm); NA = seedling did not survive or data point not available (n = 1)
EMF_colonization_% - root percent colonization by ectomycorrhizal fungi (unit = %); only measured for willow and spruce; NA = species not assessed, seedling did not survive or data point not available (n = 1)
EMF_richness - richness of ectomycorrhizal fungi morphotypes; (unit = # of morphotypes); only measured for spruce; NA = seedling did not survive or species not assessed
non_AMF_fungal_endophyte_colonization_% - root percent colonization by non-arbuscular mycorrhizal endophytic fungi (unit = %); only measured for willow and cedar seedlings; NA = species not assessed, seedling did not survive or data point not available (n = 1)
AMF_colonization_% - root percent colonization by arbuscular mycorrhizal fungi (unit = %); only measured for willow and cedar seedlings; NA = species not assessed, seedling did not survive or data point not available (n = 1)
root_length_cm - specific root length (unit = cm); only measured for spruce and cedar seedlings; NA species not assessed or seedling did not survive
foliar_N_% - foliar nitrogen content (unit = %); NA = seedling did not survive or data point not available (n = 5; typically due to insufficient biomass for anlaysis)
foliar_C_% - foliar carbon content (unit = %); NA = seedling did not survive or data point not available (n = 5; typically due to insufficient biomass for anlaysis)
foliar_CN_ratio - foliar carbon to nitrogen ratio (no unit); NA = seedling did not survive or data point not available (n = 5; typically due to insufficient biomass for anlaysis)

Code/software

Data prepared in Excel but can be viewed using LibreOffice Calc

Access information

Other publicly accessible locations of the data: None

Data was derived from the following sources: greenhouse study