DOI: 10.5061/dryad.jq2bvq8jj
title: Data from: Root traits and soil legacies drive species competition outcomes

description: Plant competition can be affected by plant functional traits but also by
 differences in fitness mediated by soil microbes. Climatic conditions such
 as drought further influence plant competition. Yet little is known about
 how soil microbes and drought interact with species with distinct root
 traits differences and how this influences plant competition outcomes. We
 grew three plant species that co-occur in temperate grasslands in China
 (Stipa krylovii, Artemisia frigida, Agropyron cristatum) in monocultures
 and mixtures and subjected the plant combinations to five soil inocula
 (root-associated soil of S.krylovii, A.frigida, A.cristatum, an equal
 mixture of the three root zone soils, and sterilized soil) as well as to a
 drought treatment. The relative change in plant biomass was used to
 determine plant competition outcomes. The three species exhibited clear
 differences in competitive abilities with A.cristatum &gt; S.krylovii
 &gt; A.frigida, and soil inocula or the drought treatment did not
 change the order. The relative yield (RY) of plants was affected by soil
 inocula, drought and plant arrangement. The strongest competitor,
 A.cristatum, with high total root length, root surface area, and root
 volume experienced more negative biotic feedback, and drought enhanced the
 magnitude of these negative effects. On the contrary, the most inferior
 competitor, A.frigida, with high specific root length tended to have
 neutral or positive biotic feedback, and drought had no effect. Further,
 the RY and fitness difference (reflected as the competitive ability in the
 mixture) of the three species was differentially influenced by root traits
 and plant-soil feedback. RY of A.cristatum could be predicted by the
 feedback effect in the mixture, and the fitness difference was mainly
 related to root traits. Both RY and fitness differences of A.frigida (the
 weakest competitor) could be predicted by root trait differences and
 feedback effects. Differences in root traits were the best predictors of
 the intermediate competitor S.krylovii. Our study shows that competition
 outcomes of co-existing species depend on root traits and species-specific
 PSF effects in mixture. Future work should examine the mechanisms that
 explain how plant competition and soil microbial heterogeneity act in
 conjunction with climate change in influencing plant coexistence.
description: # Root traits and soil legacies drive species competition outcomes
 **Experimental Procedures:** 1. **Experimental Design:** * **Objective:**
 To evaluate how soil microbes and drought impact the competition between
 three plant species * **Plant Species:** *Stipa krylovii,* *Artemisia
 frigida*, and *Agropyron cristatum*. * **Treatment Groups:** * Plant
 arrangement: monoculture and mixture * Soil inocula: root zone soil of
 S.krylovii (SK), A.frigida (AF), *A.cristatum* (AC), the mixed root zone
 soil of the three species  and sterilized  MIX inocula * Drought
 treatment: wet and dry * **Replications:** Each treatment had 4
 replicates. 2. **Methods:** * **Soil Preparation:** Soil was inoculated
 and water treatment with high and low amounts were added according to the
 treatment plan. * **Planting:** Seeds of *Stipa krylovii,* *Artemisia
 frigida*, and *Agropyron cristatum* were sown in pots with treated soil. *
 **Growth Conditions:** Plants were grown in a controlled environment with
 constant temperature, humidity, and light conditions. * **Measurements:**
 Relative yield, PSF, dertabiomass, root traits **Results:** * **Plant
 competition ability:** The three species exhibited clear differences in
 competitive abilities with *A.cristatum* &gt; *S.krylovii* &gt;
 *A.frigida*, and soil inocula or the drought treatment did not change the
 order. * **The relative yield:** The relative yield (RY) of plants was
 affected by soil inocula, drought and plant arrangement. * **Root traits
 and PSF:** *The strongest competitor, A.cristatum,* with high total root
 length, root surface area, and root volume experienced more negative
 biotic feedback, and drought enhanced the magnitude of these negative
 effects. On the contrary, the most inferior competitor, A.frigida, with
 high specific root length tended to have neutral or positive biotic
 feedback, and drought had no effect. **Files in Dataset: **In the
 Fulldata_xlsx, the following tabs are present: 1. **data_**
 **Biotic-ΔPSF.csv:** * Columns: Species, Plant arrangement, Soil inocula,
 Biotic-ΔPSF * Description: Contains measurements of Biotic-ΔPSF for all
 treatments and replicates. 2. **data_** **Specific-ΔPSF.csv:** * Columns:
 Species, Plant arrangement, Soil inocula, Specific-ΔPSF * Description:
 Contains the count of Specific-ΔPSF for all treatments and replicates. 3.
 **data_** **BioticPSF-dertabiomass-RY.csv:** * Columns: Plant arrangement,
 species, Drought treatment, Soil inocula, PSFmix, PSFmono, dertabiomass,
 RY * Description: Includes the average of BioticPSF, dertabimass, RY under
 all treatments. 4. **data_** **SpecificPSF-dertabiomass-RY.csv:** *
 Columns: Species, Drought treatment, Plant arrangement, Soil inocula,
 PSFmix, PSFmono, dertabiomass, RY * Description: Includes the average of
 SpecificPSF, dertabiomass, RY under all treatments. 5. **data_** **FD and
 dertabiomass and RY.csv:** * Columns: Drought treatment, Soil inocula,
 Plant arrangement,  Species, RY, dertabiomass,  SRL, ARD, TRL, RTD, RSA,
 RV,    Fdis * Description: Includes the average of RY,  dertabiomass, FDis
 for single and multiple root traits under all treatments. 6. **data_**
 **Root traits.csv:** * Columns: Species, Soil inocula, Drought treatment,
 SRL, ARD,  TRL, RTD, RSA, RV * Description:  Contains measurements for
 root traits for all treatments and replicates. 7.  **data_** **Average
 root traits.csv:** * Columns: Species, Soil inocula, Drought treatment,
 SRL, ARD , RTD, TRL, RSA, RV * Description:  Contains measurements for
 average root traits for all treatments and replicates. 8. **data_**
 **Aboveground biomass.csv:** * Columns: Species, Plant arrangement,
 Drought treatment, Soil inocula    Aboveground biomass * Description: 
 Contains measurements for Aboveground biomass of three species for all
 treatments and replicates 9. **data\_ RY.csv:** * Columns: Species, Plant
 arrangement, Drought treatment, Soil inocula,    RY  * Description:
 Contains measurements of RY for all treatments and replicates. 10.
 **data_** **RYT.csv:** * Columns: Plant arrangement, Drought treatment,
 Soil inocula,  RYT   * Description: Contains measurements of RYT for all
 treatments and replicates. 11. **data_** **dertabiomass.csv:** * Columns:
 Drought treatment, Soil inocula, dertabiomass of SK-AF, dertabiomass of
 AC-AF, dertabiomass of AC-SK. * Description: Contains measurements of
 dertabiomass for all treatments and replicates.