This readme.txt file was generated on 2023/02/23 by Jessica Savage ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Floral freezing tolerance of Minnesotan woody and semi-woody plants 2. Author Information First Author Contact Information Name: Jessica A. Savage Institution: University of Minnesota Address: 1035 Kirby Drive, 207 Swenson Science Building, Duluth, MN 55812 Email: jsavage@d.umn.edu ORCID: 0000-0002-7756-7166 3. Date of data collection (single date, range, approximate date) 2020/04/01-2024/2/1 4. Geographic location of data collection (where was data collected?): Bagley Nature Area, Duluth, MN —(46.8241° N, 92.0868° W) University of Minnesota Duluth Campus, Duluth, MN —(46° 49' 10.25" N, 92° 04' 54.12" W) 5. Information about funding sources that supported the collection of the data: National Science Foundation (IOS:1656318), the Grant-in-Aid program provided by the Office of the Vice President of Research -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: Attribution-NonCommercial-NoDerivs 3.0 United States (https://creativecommons.org/licenses/by-nc-nd/3.0/us/) 2. Links to publications that cite or use the data: Savage, J. A., S. J. Hudzinski, and M. R. Olson. 2024. Use of electrolyte leakage to assess floral damage after freezing. Applications in Plant Sciences 12: e11569. https://doi.org/10.1002/aps3.11569 3. Links to other publicly accessible locations of the data: None 4. Links/relationships to ancillary data sets: None 5. Was data derived from another source? If yes, list source(s): No 6. Recommended citation for the data: Savage, Jessica A.; Vandenheuvel, Britton; Fakhreddine, Qadry. (2024). Floral freezing tolerance of Minnesotan woody and semi-woody plants. Retrieved from the Data Repository for the University of Minnesota, https://doi.org/10.13020/4WRV-T931. --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: Day_of_flower Short description: This file contains data on the date when flowering was first observed in each study species from 2020 to 2023. B. Filename: Floral_freezing Short description: This file contains data about the study plants, floral structure and measurement of tissue damage after hard and light freeze treatments. C. Filename: Pollen_growth Short description: This file contains data on the reduction in pollen tube growth in eight species after a hard freeze. 2. Additional related data collected that was not included in the current data package: None 3. Are there multiple versions of the dataset? No -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: We studied 25 woody species that are common in Duluth, MN, USA. For three years, plants were visited 1-2 times a week in the spring to determine the date that flowers were first observed. In 2021, we collected data from 10 plants per species. We measured their height, basal diameter, and inflorescence/flower. We also measured total biomass, floral surface area, and water content of three inflorescences per plant. We sampled the same plants in 2021 and 2022 for a series of floral freezing experiments. All freezing experiments were conducted on cut flowers that were kept in rose tubes filled with water during freezing. Samples were cooled at a rate of 4ºC per hour and held at a minimum temperature for three hours in a temperature control chamber (Tenney TUJR, Thermal Product Solutions, White Deer, Pennsylvania USA). We had two temperature treatments, a hard freeze (-5ºC) and a light freeze (0ºC). Freezing damage was determined based on visual inspection and using electrolyte leakage. As a control, cut flowers were kept in a refrigerator for the duration of the freezing treatment. All samples were frozen in a -80C to determine the conductivity when the tissue was completed dead. A more detailed protocol of this procedure can be found in: Savage et al. 2024. Use of electrolyte leakage to assess floral damage after freezing. Applications in Plant Sciences: e11569. On a subset of eight species, the impact of freezing on pollen tube growth in vitro was also determined. 2. Methods for processing the data: NA 3. Instrument- or software-specific information needed to interpret the data: NA 4. Standards and calibration information, if appropriate: NA 5. Environmental/experimental conditions: All measurements were taken under lab conditions. Samples were collected outside on the University of Minnesota campus. 6. Describe any quality-assurance procedures performed on the data: All data entry was triple checked. 7. People involved with sample collection, processing, analysis and/or submission: Jessica Savage, Britton Vandenheuvel, Qadry Fakhreddine, Noel Tse Nwi, and Grace Aho ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Day_of_flower ----------------------------------------- 1. Number of variables: 6 2. Number of cases/rows: 26 3. Missing data codes: NA 4. Variable List A. Name: Species Description: Scientific name of the species B. Name: Sex Description: Sex of flowers on the plant. C. Name: Flwr_2020_DOY Description: Day of the year when the first flower was open on monitored individuals of each species in 2020. Flowers were considered open when the petals were reflexed and/or they had a receptive stigma/were releasing pollen. Plants were monitored weekly. In 2020, we were not able to visit individuals of seven species (A. androsaemifolium, C. rugosa, D. lonicera, R. blanda, S. dulcamara, T. americana, and V. lentago) and relied on regular images posted on iNaturalist in the area to determine the date of first flower. D. Name: Flwr_2021_DOY Description: T Day of the year when the first flower was open on monitored individuals of each species in 2021. Flowers were considered open when the petals were reflexed and/or they had a receptive stigma/were releasing pollen. Plants were monitored weekly. E. Name: Flwr_2022_DOY Description: Day of the year when the first flower was open on monitored individuals of each species in 2022. Flowers were considered open when the petals were reflexed and/or they had a receptive stigma/were releasing pollen. Plants were monitored weekly. F. Name: Flwr_2023_DOY Description: Day of the year when the first flower was open on monitored individuals of each species in 2023. Flowers were considered open when the petals were reflexed and/or they had a receptive stigma/were releasing pollen. Plants were monitored weekly. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Floral_freezing ----------------------------------------- 1. Number of variables: 23 2. Number of cases/rows: 270 3. Missing data codes: NA 4. Variable List A. Name: Collection_date Description: Date when the samples were first collected. Flowers were in full bloom on this date. Reported as day-month-year. B. Name: Sex Description: Sex of flowers on the plant. C. Name: Species Description: Scientific name of the species D. Name: Form Description: Growth form. All plants are classified as shrub or tree. E. Name: plant_id Description: Number of individual plant. F. Name: Height_m Description: Height of plant, measured to the highest liviing tissue on the plant. Measured manually with a ruler or using a clinometer. Reported in meters. G. Name: Basal_area_cm2 Description: The estimated cross-sectional area of the stem at the base near the ground. The diameter of every stem in the plant was measured and used to estimate their area assuming the stems were a complete circle. The area of all the stems was added to get the basal area for the entire plant. Reported in centimeters squared. H. Name: Plant_infl_count Description: An estimate of the number of inflorescences on the plant. I. Name: Flwrs_per_infl Description: The average number of flowers per inflorescence on the plant based on three flowers J. Name: Plant_flwr_count Description: An estimate of the total number of flowers on each plant based on the flowers per inflorescence and the estimated number of inflorescences. K. Name: Flower_SA_cm2 Description: The average surface area of a flower. With petalous flowers, petals were removed, laid on a flatbed scanner and images. We estimated the surface area of three flowers/inflorescences as two times the projected area of the petals. Reported in centimeters squared. L. Name: Infl_SA_cm2 Description: The average surface area of an inflorescence. For petalous species, this was determined as the flower surface area multiplied by the number of flowers per inflorescence. In catkins, it was determined by assuming the catkins were a geometric shape like a cone or a cylinder and measuring their length and diameter. Reported in centimeters squared. M. Name: Level_measurement Description: Indicates whether flowers were measured on a inflorescence- or flower-level. N. Name: Infl_wet_wt_g Description: The average wet weight of an inflorescence based on 3 inflorescences. For flowers that were measured on a flower-level, this value was determined as the average flower wet weight times the average number of flowers per inflorescence. Measured in grams. O. Name: Infl_dry_wt_g Description: The average dry weight of an inflorescence based on 3 inflorescences. For flowers that were measured on a flower-level, this value was determined as the average flower dry weight times the average number of flowers per inflorescence. Measured in grams. P. Name: Flwr_wet_wt_g Description: The average wet weight of a flower based on 3 inflorescences. Measured in grams. Q. Name: Flwr_dry_wt_g Description: The average dry weight of a flower based on 3 inflorescences. Measured in grams. R. Name: Total_Flwr_wt_per_plant_kg Description: The total dry mass of floral tissue on the plant reported in kg. This value was calculated the average mass of a flower multiplied by the number of flowers on the plant. S. Name: WC Description: Water content of the floral tissue reported as a ratio. T. Name: Date_measure_5 Description: The date that the first conductivity measurements were taken after the hard freeze treatment (-5°C). Reported as day-month-year. U. Name: Index_injury_5 Description: The index of injury measured for the flowers after a hard freeze (-5°C). Reported as a value that is constrained between 0 and 1. V. Date_measured_0 Description: The date that the first conductivity measurements were taken after the light freeze treatment (0°C). Reported as day-month-year. W. Name: Index_injury_0 Description: The index of injury measured for the flowers after a light freeze (0°C). Reported as a value that is constrained between 0 and 1. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Pollen_growth ----------------------------------------- 1. Number of variables: 3 2. Number of cases/rows: 63 3. Missing data codes: NA 4. Variable List A. Name: Species Description: Scientific name of the species. B. Name: plant_id Description: Number of individual plant. C. Name: Reduction Description: The percent reduction in pollen tube growth observed based on seven individuals per species. Pollen was germinated on agar pads and subjected to one of three treatments: a control where samples were kept on the benchtop in the lab, a freezing treatment where they were frozen to -5ºC using our standard freezing cycle explained above, and a recovery treatment where the samples were frozen and given time to continue growth after the treatment. The reduction in pollen tube growth (R) in the recovery sample (Lr) compared to the control (Lc) in reference to the freezing treatment (Lf) for each species was calculated based on ten pollen grains per treatment and species combination using the equation: R=(Lc-Lr)/(Lc-Lf) For more detailed information on the protocol and calculations, please see published journal article.