DOI: 10.5061/dryad.xwdbrv1nw
title: Data from: High sensitivity of herbaceous legumes to freezing: insights from a multi-year snow removal study

description: Reductions in snow cover resulting from winter climate change are
 anticipated to increase the intensity of freezing exposure for
 overwintering herbaceous plants in many northern temperate regions. We
 examined whether herbaceous legumes, a key functional group responsible
 for increasing soil nitrogen inputs, are more sensitive to freezing than
 non-leguminous plants in northern temperate plant communities. We
 conducted snow removal experiments for three years in three herbaceous
 plant communities (a fallow area, an old field and a restored prairie) and
 recorded plant cover and biomass responses. For all three years, there
 were substantial decreases in legume biomass in response to snow removal
 for the fallow area (reductions of 70%, 90% and 50%; primarily Melilotus
 albus and M. officinalis) and old field (reductions of 50%, 60% and 50%;
 primarily Trifolium pratense and Lotus corniculatus), whereas there were
 no consistent significant reductions in biomass across years for the other
 herbaceous functional groups (graminoids and non-leguminous forbs). In
 contrast, in the restored prairie, dominated by the native legume
 Desmodium canadense, there were no consistent snow removal effects on the
 biomass of legumes or any other functional groups across years, although
 snow removal did reduce the percent cover of this species early in the
 growing season. Our results suggest that increased soil freezing via
 reductions in snow cover can have a stronger negative effect on some
 legumes than on other functional groups in northern temperate herbaceous
 plant communities, potentially reducing soil nitrogen inputs.
description: # High sensitivity of herbaceous legumes to freezing: insights from a
 multi-year snow removal study
 [https://doi.org/10.5061/dryad.xwdbrv1nw](https://doi.org/10.5061/dryad.xwdbrv1nw) ## **Description of the data and file structure** **Dataset Overview:** This dataset contains the data used to generate figures and tables in Rycroft and Henry (2025), which tested the hypothesis that herbaceous legumes are more sensitive to freezing than non-leguminous plants in northern temperate plant communities. The study was conducted within three herbaceous plant communities: an old field, a restored tallgrass prairie, and a fallow area. Legume species investigated at each site were: old field –red clover (*Trifolium pratense* L.) and bird’s-foot trefoil (*Lotus corniculatus* L.); tallgrass prairie –showy tick-trefoil (*Desmodium canadense* (L.) DC.); and fallow –white sweet clover (*Melilotus albus* Medik.) and yellow sweet clover (*Melilotus officinalis* (L.) Pall.), with Melilotus spp. pooled for analysis due to the high interannual variation in the abundance of each species. Within each site, ten pairs of 1 m × 1 m plots (20 plots per site; 60 plots total) we designated and randomly assigned to either a snow removal or control treatment; Soil temperature loggers (LogTag TRIX-8, MicroDAQ, NH, USA) were placed 2 cm beneath the soil surface within a subset of both the snow removal and control plots at each site (n=3 per treatment within the prairie and old field sites; n=3 for snow removal and n=2 for control plots within the fallow site) to measure soil temperatures hourly. Plant cover for each plot was assessed through visual surveys in the growing season following treatment application, with multiple surveys conducted each year to assess different periods of the growing season and to account for variation in phenology among species. Aboveground plant material for each plot was harvested at the peak of the growing season (August–September, dependent on site) from a 60 cm × 40 cm section of each plot. The aboveground plant material was then sorted by plot into functional groups – non-leguminous forbs (NLF), leguminous forbs (LF), and graminoids (GR); within LF, plant material was further separated to the species-level. To examine treatment effects on biomass, a mixed effects model with year, functional group, and treatment (snow removal versus control) as fixed effects and plot pair as a random effect was used for each site; linear contrasts were then used to directly compare whether treatment-induced changes in legume biomass differed significantly from the changes exhibited by the other functional groups. In addition, the responses of total, functional group, and legume (species-level) aboveground biomass to snow removal were analyzed using paired one-tailed t-tests within each plant community for each year. Snow removal effects on species-level cover were assessed for each year using paired one-tailed t-tests for each survey period; species-level cover was analyzed only for the dominant species (i.e., those in all or nearly all plots) and target legumes within each plant community. All analyses were conducted using JMP version 17 (SAS Institute). **Files and variables** **File: Ecosphere_Rycroft___Henry_Biomass_and_Cover_Data.xlsx** **Description:**  This MS Excel file contains 18 spreadsheets containing the plant biomass, plant cover and soil temperature data from the experiment as follows: **Sheet 1: Fallow Biomass 2019-2021** Number of variables: 14 Number of header rows: 1 Variable list: Pairs: plot pair ID Year: year of data collection Treatment: snow removal treatment              Plot #: plot ID Melilotus spp.: dry mass in grams   Graminoids: dry mass in grams         Non-Leguinous Forbs: dry mass in grams   Total legume: dry mass in grams      Total Biomass: dry mass in grams Graminoids m2: dry mass in grams per square meter        Non-Leguinous Forbs m2: dry mass in grams per square meter  Total legume m2: dry mass in grams per square meter     Total Biomass m2: dry mass in grams per square meter   Melilotus spp. m2: dry mass in grams per square meter Data type: alphanumeric, character **Sheet 2: Old field Biomass 2019-2021** Number of variables: 16 Number of header rows: 1 Variable list: Pairs: plot pair ID Year: year of data collection Treatment: snow removal treatment              Plot #: plot ID Lotus corniculatus: dry mass in grams        Trifolium pratense: dry mass in grams          Graminoids: dry mass in grams         Non-Leguinous Forbs: dry mass in grams   Legumes: dry mass in grams              Total Biomass: dry mass in grams    Total Biomass per m2: dry mass in grams per square meter          Total Legume per m2: dry mass in grams per square meter           Total NLF per m2: dry mass in grams per square meter     Total Graminoids per m2: dry mass in grams per square meter   Lotus per m2: dry mass in grams per square meter             Trifolium pratense per m2: dry mass in grams per square meter Data type: alphanumeric, character **Sheet 3: Prairie Biomass 2019-2021** Number of variables: 14 Number of header rows: 1 Variable list: Pairs: plot pair ID Year: year of data collection Treatment: snow removal treatment              Plot #: plot ID Desmodium: dry mass in grams       Graminoids: dry mass in grams         Non-Leguinous Forbs: dry mass in grams Total legume: dry mass in grams    Total Biomass: dry mass in grams Total Biomass per m2: dry mass in grams per square meter          Graminoids m2: dry mass in grams per square meter        Non-Leguinous Forbs m2: dry mass in grams per square meter  Total legume m2: dry mass in grams per square meter     Desmodium per m2: dry mass in grams per square meter Data type: alphanumeric, character **Sheet 4: Fallow Cover 2020** Number of variables: 41 Number of header rows: 1 Variable list: Plot #: plot ID Month: month of data collection      Pairs: plot pair ID        Treatment: snow removal treatment Species (columns 5-40): percent cover by species Total: total percentage cover Data type: alphanumeric, character **Sheet 5: Fallow Cover 2021** Number of variables: 40 Number of header rows: 1 Variable list: Plot #: plot ID Month: month of data collection      Pairs: plot pair ID        Treatment: snow removal treatment Species (columns 5-39): percent cover by species Total: total percent cover Data type: alphanumeric, character **Sheet 6: Old Field Cover 2020** Number of variables: 34 Number of header rows: 1 Variable list: Plot #: plot ID Month: month of data collection      Pairs: plot pair ID        Treatment: snow removal treatment Species (columns 5-33): percent cover by species Total: total percent cover Data type: alphanumeric, character **Sheet 7: Old Field Cover 2021** Number of variables: 34 Number of header rows: 1 Variable list: Plot #: plot ID Month: month of data collection      Pairs: plot pair ID        Treatment: snow removal treatment Species (columns 5-33): percent cover by species Total: total percentage cover Data type: alphanumeric, character **Sheet 8: Prairie Cover 2020** Number of variables: 49 Number of header rows: 1 Variable list: Plot #: plot ID Month: month of data collection      Pairs: plot pair ID        Treatment: snow removal treatment Species (columns 5-48): percent covered by species Total: total percentage cover Data type: alphanumeric, character **Sheet 9: Prairie Cover 2021** Number of variables: 49 Number of header rows: 1 Variable list: Plot #: plot ID Month: month of data collection      Pairs: plot pair ID        Treatment: snow removal treatment Species (columns 5-48): percent covered by species Total: total percentage cover Data type: alphanumeric, character **Sheet 10: Fallow 2018-2019** Number of variables: 15 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2     Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 11: Fallow 2019-2020** Number of variables: 18 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 12: Fallow 2020-2021** Number of variables: 9 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 13: Old Field 2018-2019** Number of variables: 18 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 14: Old Field 2019-2020** Number of variables: 18 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 15: Old Field 2020-2021** Number of variables: 18 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 16: Prairie 2018-2019** Number of variables: 18 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 17: Prairie 2019-2020** Number of variables: 18 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time **Sheet 18: Prairie 2020-2021** Number of variables: 15 Number of header rows: 1 Variable list: Date control 1: date of temperature reading in control plot 1        Time control 1: hour, minute, second of temperature reading in control plot 1  Temperature control 1: soil temperature in degrees Celsius in control plot 1     Date control 2: date of temperature reading in control plot 2        Time control 2: hour, minute, second of temperature reading in control plot 2  Temperature control 2: soil temperature in degrees Celsius in control plot 2 Date control 3: date of temperature reading in control plot 3        Time control 3: hour, minute, second of temperature reading in control plot 3  Temperature control 3: soil temperature in degrees Celsius in control plot 3                    Date snow removal 1: date of temperature reading in snow removal plot 1         Time snow removal 1: hour, minute, second of temperature reading in snow removal plot 1              Temperature snow removal 1: soil temperature in degrees Celsius in snow removal plot 1              Date snow removal 2: date of temperature reading in snow removal plot 2         Time snow removal 2: hour, minute, second of temperature reading in snow removal plot 2              Temperature snow removal 2: soil temperature in degrees Celsius in snow removal plot 2 Date snow removal 3: date of temperature reading in snow removal plot 3         Time snow removal 3: hour, minute, second of temperature reading in snow removal plot 3              Temperature snow removal 3: soil temperature in degrees Celsius in snow removal plot 3 Data type: alphanumeric, character Empty cells indicate no data were collected for a given temperature logger at that date and time