DOI: 10.5061/dryad.c866t1ghq
title: Belowground traits predict juvenile grass demography in microsites

description: Plant functional traits can be a powerful tool for predicting species
 demography in response to variable environmental conditions. However,
 accurate predictions of juvenile plant response require ontogenetically
 relevant traits that capture response to microsite variability. This is
 particularly important when considering drivers of seedling emergence,
 survival, growth, and recruitment of species in the context of population
 persistence or community assembly. We tested the effect of two
 different microsites on juvenile demography for eight perennial grass
 species in a semi-arid system in Colorado along the western edge of the
 Great Plains. We used seed and root functional traits across multiple life
 stages to predict these responses and identify mechanisms driving species’
 emergence, survival, growth, and recruitment. Contrary to our
 expectations, we found that microsites with increased soil moisture (i.e.,
 furrows) had a negative effect on grass emergence early in the season but
 no effect on recruitment at the end of the season. This was likely driven
 by the increased growth and survival of grass juveniles in furrows
 compared to grass juveniles on the surface (reduced soil moisture). We
 also found that species with more acquisitive roots—from more rapid root
 elongation—benefited from the increased soil moisture early in the season,
 but this benefit disappeared later in the season, speaking to the value of
 using life-stage-specific traits to predict early life-stage
 transitions. Variations in microsites will impact juvenile
 perennial grass demography differently depending on species’ traits across
 life stages. While species in this system typically experience wet-to-dry
 transitions across the growing season, furrows with increased soil
 moisture reduce the intensity of this dry-down and may alter demographic
 responses depending on grass functional traits across ontogeny. We found
 grass species that are adapted to take advantage of resource pulses did
 best in furrows where moisture was greater, but that species adapted to
 conserve resources under stress had limited capacity to respond to these
 resource pulses.
description: To determine emergence and recruitment response to microsites, we
 counted grass abundance throughout the growing season. In addition to
 using row-level abundances to determine emergence and recruitment, we
 tracked individual survival and growth of a subset of individuals across
 three life stages. We used seed and seedling trait data obtained from the
 greenhouse trait sampling effort described in (Larson, 2021). To quantify
 the effects of the furrows on microsite conditions, we measured soil
 moisture, soil temperature, and surface temperature within these rows with
 TOMST TMS-4 loggers (Wild et al., 2019).
description: # Belowground traits predict juvenile grass demography in microsites
 [https://doi.org/10.5061/dryad.c866t1ghq](https://doi.org/10.5061/dryad.c866t1ghq) ## Description of the data and file structure We tested the effect of two different microsites on juvenile demography for eight perennial grass species in a semi-arid system in Colorado along the western edge of the Great Plains. We used seed and root functional traits across multiple life-stages to predict these responses and identify mechanisms driving species’ emergence, survival, growth, and recruitment. ### Files and variables #### File: Grass\_Traits.csv **Description:**  ##### Variables * species: species ID codes * c3_c4: photosythetic pathway * canopy_e: canopy volume per day for the emergent life stage (2 weeks); cm3/day * height_e: height per day for the emergent life stage (2 weeks); cm/day * biomass_e: biomass per day for the emergent life stage (2 weeks); g/day * rootlength_e: root length per day for the emergent life stage (2 weeks); cm * RMR_e: root mass ratio for the emergent life stage (2 weeks); g/g * RDMC_e: root dry matter content for the emergent life stage (2 weeks); g/g * SRL_e: specific root length for the emergent life stage (2 weeks); cm/g * Rdiam_e: average root diameter for the emergent life stage (2 weeks); mm * LDMC_e: leaf dry matter content for the emergent life stage (2 weeks); g/g * SLA_e: specific leaf area for the emergent life stage (2 weeks); cm2/g * SDMC_e: shoot dry matter content for the emergent life stage (2 weeks); g/g * Sdiam_e: average shoot diameter for the emergent life stage (2 weeks); mm * RS_length_e: root to shoot ratio by length for the emergent life stage (2 weeks); cm/cm * RGR_e_s: relative growth rate, emergent to seedling stage; NA * canopy_s: canopy volume per day for the seedling life stage (6 weeks); cm3/day * height_s: height per day for the seedling life stage (6 weeks); cm/day * biomass_s: biomass per day for the seedling life stage (6 weeks); g/day * rootlength_s: root length per day for the seedling life stage (6 weeks); cm * RMR_s: root mass ratio for the seedling life stage (6 weeks); g/g * RDMC_s: root dry matter content for the seedling life stage (6 weeks); g/g * SRL_s: specific root length for the seedling life stage (6 weeks): cm/g * Rdiam_s: average root diameter for the seedling life stage (6 weeks): mm * LDMC_s: leaf dry matter content for the seedling life stage (6 weeks); g/g * SLA_s: specific leaf area for the seedling life stage (6 weeks); cm2/g * SDMC_s: shoot dry matter content for the seedling life stage (6 weeks): g/g * RGR_s_m: relative growth rate, seedling to mature stage for the mature life stage (12 weeks); NA * canopy_m: canopy volume per day for the mature life stage (12 weeks); cm3/day * height_m: height per day for the mature life stage (12 weeks); cm/day * biomass_m: biomass per day for the mature life stage (12 weeks); g/day * rootlength_m: estimated root length per day for the mature life stage (12 weeks); cm * RMR_m: root mass ratio for the mature life stage (12 weeks); g/g * RDMC_m: root dry matter content for the mature life stage (12 weeks); g/g * SRL_m: specific root length for the mature life stage (12 weeks); cm/g * Rdiam_m: average root diameter for the mature life stage (12 weeks); mm * LDMC_m: leaf dry matter content for the mature life stage (12 weeks); g/g * RGR_e_m: relative growth rate, emergent to mature stage for the mature life stage (12 weeks); NA * seedmass: mass of individual seed for the mature life stage (12 weeks); mg #### File: Treatment\_rows.csv **Description:** Dataframe detailing the manipulations that occurred in each seeded row ##### Variables * BLOCK: Labeled pair of two rows (rows are 14 plots long) * PLOT: 2m long by 3 m wide rectangular plots containing four reps of seeded rows * REP: single, 2m long drill seeded row (2m parallel to 2m side of plot) * species: seeded species identitity; USDA codes (first 2 letters of genus, first 2 letters of species) * seed_treatment: Type of treatment (priming and/or agglomeration) appleid to seed prior to seeding * planting: Method of drill seeding; microsite type #### File: Grass\_Emergence.csv **Description:** Raw count data for each row of seeded grasses across the first growing season ##### Variables * BLOCK: Labeled pair of two rows (rows are 14 plots long) * PLOT: 2m long by 3 m wide rectangular plots containing four reps of seeded rows * REP: single, 2m long drill seeded row (2m parallel to 2m side of plot) * 2 week: number of grass seedlings at 2 weeks post initial emergence per 2m row * 6 week: number of grass seedlings at 6 weeks post initial emergence 2m row * 12 week: number of grass seedlings at 12 weeks post initial emergence per 2m row * Notes: Field Observations #### File: all\_demographic.csv **Description:** Survival and growth data for each tagged grass individual across the first growing season.  ##### Variables * species: seeded species identitity; USDA codes (first 2 letters of genus, first 2 letters of species) * seed_treatment: type of treatment (priming and/or agglomeration) appleid to seed prior to seeding * planting: method of drill seeding; microsite type * plot: 2m long by 3 m wide rectangular plots containing four reps of seeded rows * rep: single, 2m long drill seeded row (2m parallel to 2m side of plot) * number_total: Number of tagged individual by each species by planting combination * emerge_height_mm: tallest leaf height at 2 weeks * six_wk_height_mm: tallest leaf height at 6 weeks * tw_elvewk_height_mm: tallest leaf height at 12 weeks * surv_2wk: 0 or 1 for dead or alive, respectively, at 2 weeks * surv_6wk: 0 or 1 for dead or alive, respectively, at 6 weeks * surv_12wk: 0 or 1 for dead or alive, respectively, at 12 weeks * emerg_gr: growth rate between 2 and 6 weeks * seedling_gr: growth rate between 6 and 12 weeks * recruit_gr: growth rate between 2 and 12 weeks #### File: soil\_moisture.csv **Description:** field soil moisture data from the growing season ##### Variables * date_time: probe-provided time of data collection * time_zone: region where data was collected * T1: soil temperature; celcius * T2: temperature at 1cm above the soil surface; celcius * T3: temperature 6cm above the soil surface; celcius * soil_moisture: raw soil moisture measurement (without calibration) * date: day the data was recorded * time: time the data was recorded * sensor: number of sensor * planting: method of drill seeding; microsite type * VWC: volumetric water content based on soil-specific calibration; percent ## Code/software R and R Studio ## Access information Other publicly accessible locations of the data: * None Data was derived from the following sources: * None