DOI: 10.5061/dryad.cc2fqz6bs
title: Thallus hydrophobicity: a low-cost method for understanding lichen ecophysiological responses to environmental changes

description: Premise: Methods to evaluate lichen thalli hydrophobicity were described
 in the past, but only recently this was shown to be an important
 functional trait related to water regulation dynamics that could be used
 to predict future climate change effects. Methods and Results: Our
 protocol requires only a micropipette, distilled water, a tripod and a
 phone or camera. Hydrophobicity is inferred from multiple metrics
 associated with absorption times of standardized droplets (initial and
 total absorption time). We used a dataset of 93 lichen taxa with different
 growth forms and from different biomes and demonstrated that this method
 is well suited for capturing different levels of hydrophobicity, including
 very hydrophilic species. Conclusions: Our results show that the
 measurement of lichen hydrophobicity is a rapid and low-cost method to
 assess an ecophysiologically based lichen functional trait that can be
 used with almost no limitations, including in different climates, lichen
 species, and growth forms.
description: To demonstrate that measuring thallus hydrophobicity using the
 time of absorption is most suited for capturing very hydrophilic species
 and to determine the optimal time for capturing the videos, we used a
 dataset of 93 lichen taxa with different growth forms from different
 biomes in the USA (boreal to subtropical) and a desert area in Chile (Alto
 Patache). Data was collected without any specific methodology, and
 specimens were identified to the level of species whenever it was
 possible. This dataset is part of other ongoing projects and other
 information (such as complete species identification) will be fully
 published in future publications. The present manuscript aims to show how
 effective the proposed hydrophobicity method is to be used in different
 types of environments.
description: It only requires programs that can read .csv files.
description: This README\_DATASET\_Koch et al.txt file was generated on 2023-06-08 by
 NATÁLIA M. KOCH GENERAL INFORMATION 1. Title of Dataset: Thallus
 hydrophobicity: A low-cost method for understanding lichen
 ecophysiological responses to environmental changes 2. Author Information
 A. Principal Investigator Contact Information Name: Natália M. Koch
 Institution: Department of Ecology, Evolution and Behavior, University of
 Minnesota Address: Ecology Building, 1987 Upper Buford Cir, 55108, Saint
 Paul, MN, USA Email: nkoch@umn.edu; natimkoch@gmail.com <br> B.
 Associate or Co-investigator Contact Information Name: Raúl Díaz Dominguez
 Institution: Instituto de Investigaciones Biológicas y Tecnológicas,
 Universidad Nacional de Córdoba Address: Córdoba, Argentina Email:
 raulenriquedd@hotmail.com <br> C. Associate or Co-investigator
 Contact Information Name: Ana Fávaro Institution: Department of Ecology,
 Evolution and Behavior, University of Minnesota Address: Ecology Building,
 1987 Upper Buford Cir, 55108, Saint Paul, MN, USA Email: fvaro001@umn.edu;
 anafavarovga@gmail.com <br> D. Alternate Contact Information Name:
 Daniel Stanton Institution: Department of Ecology, Evolution and Behavior,
 University of Minnesota Address: Ecology Building, 1987 Upper Buford Cir,
 55108, Saint Paul, MN, USA Email: stan0477@umn.edu 3. Date of data
 collection (single date, range, approximate date): 2015 (Chile), from 2021
 to 2022 (USA) 4. Geographic location of data collection: Chile and United
 States 5. Information about funding sources that supported the collection
 of the data: funds were granted as startup to Daniel Stanton by the
 University of Minnesota SHARING/ACCESS INFORMATION 1.
 Licenses/restrictions placed on the data: NO 2. Links to publications that
 cite or use the data: not available yet 3. Links to other publicly
 accessible locations of the data: NA 4. Links/relationships to ancillary
 data sets: NA 5. Was data derived from another source? NO A. If yes, list
 source(s): 6. Recommended citation for this dataset: Koch, Natalia M.,
 Dominguez, Raul D., Fávaro, Ana, Stanton, Daniel E. 2023. Thallus
 hydrophobicity: A low-cost method for understanding lichen
 ecophysiological responses to environmental changes. Applications in Plant
 Sciences. DATA & FILE OVERVIEW 1. File List: USA\_Hydro\_final.csv
 - matrix of 96 rows (taxa/observations) and 4 columns (site and
 hidrophobicity information). Chile\_Hydro\_final.csv - matrix of 94 rows
 (taxa/observations) and 4 columns (site and hidrophobicity information).
 All\_taxa\_sites.csv - matrix of 93 rows (taxa) and 3 columns (sampling
 location and geographic coordinates). 2. Relationship between files, if
 important: Files are linked by the name of species/taxa. 3. Additional
 related data collected that was not included in the current data package:
 NA 4. Are there multiple versions of the dataset? NO A. If yes, name of
 file(s) that was updated: i. Why was the file updated? ii. When was the
 file updated? METHODOLOGICAL INFORMATION 1. Description of methods used
 for collection/generation of data: To demonstrate that measuring thallus
 hydrophobicity using the time of absorption is most suited for capturing
 very hydrophilic species and to determine the optimal time for capturing
 the videos, we used a dataset of 93 lichen taxa with different growth
 forms and from different biomes in the USA (boreal to subtropical) and a
 desert area in Chile (Alto Patache). Data was collected without any
 specific methodology, and specimens were identified to the level of
 species whenever it was possible. This dataset is part of other udergoing
 projects and other information (such as complete species identification)
 will be fully published in future publications. The present manuscript
 aims to show how effective the proposed hydrophobicity method is to be
 used in different types of environments. 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: The
 hydrophobicity data was generated (filmed) in the lab, following the below
 protocol: Thallus hydrophobicity, detailed protocol Materials Digital
 camera or phone with video capacity Micropipette (10 or 20 microliter)
 Micropipette tips (10 or 20 microliter) Distilled water Stands/mounts for
 camera and specimen A black background (optional) Lights (optional) Video
 recording Before the analysis, make sure the specimens are completely dry.
 If the samples were in a freezer before the hydrophobicity analysis, take
 them out of the freezer and let them sit overnight in dry conditions.
 Place the specimen on a flat surface and arrange the camera, at the same
 height as the specimen surface. Place the specimen horizontally, in a way
 that maximizes the horizontal surface available for water droplets (by
 choosing the side with a bigger flat area, for example). For smaller taxa,
 it can be possible to have multiple specimens in the same recording. Make
 sure that the specimen is in focus and well-lit. Black background behind
 the specimen and diffuse photography lights can be used to improve
 visualization of the droplets when analyzing the video and to reduce
 shadows, but they are not strictly necessary. Start recording. We
 recommend using 24 frames per second (fps) or higher shutter speed. Gently
 place a 10µl droplet of distilled water on the surface of the specimen,
 choosing an undamaged, dry, and (ideally) horizontal region. It is
 important that the specimen does not show areas of chlorosis covering more
 than 50% of the thallus, and/or similar amount of tissue death. Also,
 avoid placing droplets on apothecia since they are hydrophilic structures.
 The droplet needs to be formed before being placed on the lichen surface.
 Add additional (ideally at least three) droplets to dry locations on the
 specimen, if possible. Properties change dramatically on wet surfaces;
 thus, if a droplet is accidentally added to one of these wet spots, take
 note of it and exclude it from the data analyses. If a droplet merges with
 another droplet, also exclude both droplets from the analyses. Record the
 video until all droplets are absorbed or until it completes 150 seconds
 after the application of the last droplet. Some highly hydrophobic species
 will take so long to absorb that it is unreasonable to film past 150
 seconds. Save files with file names carefully reflecting relevant specimen
 information. Video processing Video processing can be done manually using
 any video playback software your operating system comes with. For each
 droplet, record (a) the time in seconds between contact with the surface
 and the start of absorption and (b) the time in seconds between the
 contact with the surface and apparent complete absorption of the droplet.
 The beginning of the absorption is considered when the volume of the
 droplet starts to change, which sometimes may be slow, others, very fast.
 If the specimen is very hydrophilic, the time between the droplet getting
 in touch with the surface and the start of its absorption (measurement a)
 can be 0 because the droplet is rapidly absorbed. If the specimen is very
 hydrophobic, the time between the droplet getting in contact with the
 surface and complete absorption (measurement b) can be 0 because the
 droplet is not absorbed in less than 150 seconds. 6. Describe any
 quality-assurance procedures performed on the data: NA 7. People involved
 with sample collection, processing, analysis and/or submission: Natália M.
 Koch - Field sampling and species identification (USA), data analyses and
 submission Raúl Díaz Dominguez - Species curation/identification (Chile),
 data analyses Daniel Stanton - Field sampling (Chile and USA), data
 analyses Abigail Meyer - Field sampling (USA) Ana Fávaro - Data analyses
 and submission DATA-SPECIFIC INFORMATION FOR: README\_DATASET\_Koch et
 al.txt Table containing the list of lichens species sampled in the USA,
 their times of initial absorption and total absorption, and hydrophobicity
 status. Hydrophobicity status 0 = hydrophobic; Hydrophobicity status 1 =
 hydrophilic. USA\_Hydro\_final.csv 1. Number of variables: 4 2. Number of
 cases/rows: 96 3. Variable List: Columns (variables) <br> Site
 (categorical data): Country where species were sampled US = United States
 of America Species (categorical data): List of lichen species Time\_start
 (continuous data): Column with time (in seconds) for the droplet to start
 being absorbed. Time\_abs (continuous data): Column with total time (in
 seconds) for the droplet to be fully absorbed. Hydrophobicity (categorical
 data): Column with thallus hydrophobicity status 0 = hydrophobic; 1 =
 hydrophilic 4. Missing data codes: NA 5. Specialized formats or other
 abbreviations used: US - United States of America (USA) Time-start - time
 of initial absorption Time\_abs - time of the complete absorption Table
 containing the list of lichen taxa sampled in the Chile, their times of
 initial absorption and total absorption, and hydrophobicity status.
 Hydrophobicity status 0 = hydrophobic; Hydrophobicity status 1 =
 hydrophilic. Chile\_Hydro\_final.csv 1. Number of variables: 4 2. Number
 of cases/rows: 94 3. Variable List: Columns (variables) Site (categorical
 data): Site where taxa were sampled Patache = The Alto Patache fog oasis,
 northern Chile Taxon (categorical data): List of lichen taxa Time\_start
 (continuous data): Column with time (in seconds) for the droplet to start
 being absorbed. Time\_abs (continuous data): Column with total time (in
 seconds) for the droplet to be fully absorbed. Hydrophobicity (categorical
 data): Column with thallus hydrophobicity status 0 = hydrophobic; 1 =
 hydrophilic 4. Missing data codes: NA 5. Specialized formats or other
 abbreviations used: Patache - Alto Patache area (Chile) Time\_start - time
 of initial absorption Time\_abs - time of the complete absorption
 All\_taxa\_sites.csv 1. Number of variables: 3 2. Number of cases/rows: 93
 3. Variable List: Columns (variables) Taxon name (categorical data): List
 of lichen taxa Sampling location (categorical data): Site where taxa were
 sampled Latitude (gis data): List of latitudes of the sampled sites
 Longitude (gis data): List of longitudes of the sampled sites 4. Missing
 data codes: NA 5. Specialized formats or other abbreviations used: NA