This readme.txt file was generated on 2020/05/14 by Erin O'Connell and Jessica Savage ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Understory light environment measured in 2017 and 2018 at Bagley Nature Area in Duluth, MN 2. Author Information Principal Investigator 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 First Author Contact Information Name: Erin O'Connell Institution: University of Minnesota Address: 1035 Kirby Drive, 207 Swenson Science Building, Duluth, MN 55812 Email: oconn877@d.umn.edu ORCID: 0000-0002-7983-7959 3. Date of data collection (single date, range, approximate date) 2017/02/16-2018/11/11 4. Geographic location of data collection (where was data collected?): Bagley Nature Area, Duluth, MN 5. Information about funding sources that supported the collection of the data: National Science Foundation (IOS:1656318), the University of Minnesota – Duluth, and the Integrated Biosciences Graduate Program -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: Manuscript copyright held by Biological Invasions. 2. Links to publications that cite or use the data: O'Connell, E. and Savage, J. (2020). Extended leaf phenology has limited benefits for invasive species growing at northern latitudes. Biological Invasions 22(10): 2957-2974. https://doi.org/10.1007/s10530-020-02301-w 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: O'Connell, Erin and Savage, Jessica A. (2020). Understory light environment measured in 2017 and 2018 at Bagley Nature Area in Duluth, MN. Retrieved from the Data Repository for the University of Minnesota. https://doi.org/10.13020/mwhd-jy06. -------------------- DATA & FILE OVERVIEW -------------------- 1. File List A. Filename: Canopy_openness Short description: This file contains data from monthly hemispherical photographs of the overstory canopy taken above 80 study plants. B. Filename: Understory_light_monthly Short description: This file contains data on monthly understory light availability above the study plants. C. Filename: Understory_light_daily Short description: This file contains data on daily understory light availability above the study plants logged every fiften minutes during six months. 2. Relationship between files: All of these files are data collected during a two year project at Bagley Nature Area, Duluth MN investigating phenology, growth, freezing tolerance, and carbon gain of invasive and native shrubs. 3. Additional related data collected that was not included in the current data package: Yes, there there are two additional data packages: O'Connell, Erin and Savage, Jessica A. (2020). Plant phenology, growth, freezing damage, and carbon gain data observed from 2017 to 2018 on wood plants growing at Bagley Nature Area in Duluth, MN. O'Connell, Erin and Savage, Jessica A. (2020). Maximum carbon assimilation model for understory wood plants growing at Bagley Nature Area in Duluth, MN. 4. Are there multiple versions of the dataset? yes/no Yes, data in the files "Understory_light_monthly" and "Understory_light_daily" are also included in the data package: O'Connell, Erin and Savage, Jessica A. (2020). Maximum carbon assimilation model for understory wood plants growing at Bagley Nature Area in Duluth, MN. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: See descriptions under "Variable Lists" below and publication for details. A. Canopy_openness Hemispherical photographs of the overstory canopy were taken using a fish-eye lens above ten plants per species 1-2 times a month (April - November) in 2017. B. Understory_light_monthly Percent light transmittance on cloudy days was measured above ten plants per species in May, July, September, and October 2018. Each measurement is the ratio of the light level above the plant to the light level recorded simultaneously in full sun. C. Understory_light_daily Temperature and light were measured at 15-minute intervals on 11-30 days per month (May, July, August, September, October, and November 2018) using lux sensors mounted at the top of six plants. 2. Methods for processing the data: A. Canopy_openness Hemispherical photographs were processed with an ImageJ plugin created by Beckschafer. Beckschäfer P (2015) Hemispherical_2.0 Batch processing hemispherical and canopy photographs with ImageJ – User Manual. doi: 10.13140/RG.2.1.3059.4088 3. Instrument- or software-specific information needed to interpret the data: NA 4. Standards and calibration information, if appropriate: NA 5. Environmental/experimental conditions: NA 6. Describe any quality-assurance procedures performed on the data: All data entry was double checked. 7. People involved with sample collection, processing, analysis and/or submission: Erin O'Connell, Jessica Savage, Alex Peichel, Natalie McMann, Collin Monette, Kennedy Mosher, Thomas Kiecker, Max Bonfig, Shauna Blake, Sydney Hudzinski, Rishika Quick-Singh, and Nihaar Joshi ---------------------------------------------- DATA-SPECIFIC INFORMATION FOR: Canopy_openness ---------------------------------------------- 1. Number of variables: 6 2. Number of cases/rows: 677 3. Missing data codes: Code/symbol: NA Definition: Data not available. 4. Variable List A. Name: Date Description: Date that canopy photgraph was taken [MM/DD/YYYY]. B. Name: Species Description: Scientific name of the species [Genus_species]. C. Name: Plant_ID Description: Unique number given to each plant observed in the study. D. Name:No_of_gaps Description: The number of gaps (isolated areas of the photo which contain sky) in the image. E. Name: Gap_area Description: Total area of gaps (sky) [pixels]. F. Name: Gap_fraction Description: The total gap area divided by the the total lens area, resulting in the percent of the photograph containing sky [%]. ------------------------------------------------------- DATA-SPECIFIC INFORMATION FOR: Understory_light_monthly ------------------------------------------------------- 1. Number of variables: 11 2. Number of cases/rows: 327 3. Missing data codes: Code/symbol: NA Definition: Data not available. 4. Variable List A. Name: Species Description: Scientific name of the species [Genus_species]. B. Name: Plant_ID Description: Unique number given to each plant observed in the study. C. Name: Date Description: Date measurement was taken [MM/DD/YYYY]. D. Name: Time Description: Time of measurement [HH:MM:SS]. E. Name: Month Description: Month measurement was taken. F. Name: Season Description: Season measurement was taken. "Season" corresponds with "Month" as follows: "May" = "Spring," "Jun" = "SummerI," "Aug" = "SummerII," "Sep" = "Fall." G. Name: PPFD_plant Description: Photosynthetic photon flux density (PPFD) measured above each study plant [umol photons m^-2 s^-1], averaged over 15 seconds. Measurements were taken simultaneously with LUX_plant and LUX_full_sun. H. Name: LUX_plant Description: Light level measured above each study plant [lumens m^-2], averaged over 15 seconds. Measurements were taken simultaneously with PPFD_plant and LUX_full_sun. I. Name: LUX_full_sun Description: Light level measured in an open area with no canopy cover [lumens m^-2], averaged over 15 seconds. Measurements were taken simultaneously with PPFD_plant and LUX_plant. J. Name: LUX_percent Description: Percent light transmittance measured above each plant [%]. LUX_percent = (LUX_plant / LUX_full_sun) * 100. K. Name: Bin Description: Catergorical bin numbers assigned to each plant based on LUX_percent values within each season. There are six bins per season. ----------------------------------------------------- DATA-SPECIFIC INFORMATION FOR: Understory_light_daily ----------------------------------------------------- 1. Number of variables: 9 2. Number of cases/rows: 65897 3. Missing data codes: Code/symbol: NA Definition: Data not available. 4. Variable List A. Name: Logger_No Description: Numbers 1-6 assigned to each logger unit (HOBO Pendant Temp/Light, 8k, UA-002-08, Onset Computer Corporation, Bourne, Massachusetts USA). B. Name: Species Description: Scientific name of the species [Genus_species] above which the sensor was mounted. C. Name: Plant_ID Description: Unique number of the plant above which the sensor was mounted. D. Name: Month Description: Approximate month measurement was taken. Measurements are grouped into four months: May – open canopy, July – closed canopy and long daylength, September – closed canopy and short daylength, and October – open canopy. E. Name: Date Description: Date measurement was taken [MM/DD/YYYY]. F. Name: Time Description: Time of measurement [HH:MM:SS]. G. Name: Temperature Description: Temperature logged above each study plant every fifteen minutes [degrees Celcius]. H. Name: LUX Description: Light level logged above each study plant every fifteen minutes [lumens m^-2]. I. Name: Weather Description: Days were designated as "sunny" or "cloudy" based on light measurements. Only data from sunny days were included in the carbon assimilation model presented in the publication.