Data from: Climate refugia along Lake Superior’s shores: Disjunct arctic-alpine plants rely on cool shoreline temperatures but are unlikely to persist under climate warming
Data files
Jun 03, 2024 version files 966.30 KB
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Hillman_land_temperature_raw_data.csv
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Hillman_species_occurrences_raw_data.csv
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README.md
Abstract
Climate refugia can serve as remnant habitat or stepping stones for species dispersal under climate warming. The largest freshwater lake by surface area, Lake Superior, USA and Canada, serves as a model system for understanding cooling-mediated local refugia, as its cool water temperatures and wave action have maintained shoreline habitats suitable for southern disjunct populations of arctic-alpine plants since deglaciation. Here we seek to explain spatial patterns and environmental drivers of arctic-alpine plant refugia along Lake Superior’s shores, and assess future risk to refugia under moderate (+3.5 °C) and warmest (+5.7 °C) climate warming scenarios. First, we examined how the interactive effects of summer surface water temperatures and wind affected onshore temperatures, resulting in areas of cooler refugia. Second, we developed an ecological niche model for presence of disjunct arctic-alpine refugia (pooling 1253 occurrences from 58 species) along the lake’s shoreline. Third, we fit species distribution models for 20 of the most common arctic-alpine disjunct species and predicted presence to identify refugia hotspots. Finally, we used the two climate warming scenarios to predict changes in presence of refugia and disjunct hotspots. Bedrock type, elevation above water, inland distance, July land surface temperature from MODIS/Terra satellite, and near-shore depth of water were the best predictors of disjunct occurrences. Overall, we predicted 2,236 km of the shoreline (51%) as disjunct refugia habitat for at least one species under current conditions, but this was reduced to 20% and 7% with moderate (894 km) and warmest (313 km) climate change projections.
README: Title of Dataset: Climate refugia along Lake Superior’s shores: disjunct arctic-alpine plants rely on cool shoreline temperatures but are unlikely to persist under climate warming
This dataset contains species occurrence records for 59 disjunct arctic-alpine species at Lake Superior. Hillman_species_occurrences_raw_data.csv contains location data for all occurrence records, as well as spatial data for elevation, bedrock type, depth of water within 10 km of shore, log of Euclidean distance from shore, and land surface temperature from MODIS/Terra satellite.
Data were used to build species distribution models for all species considered disjunct and 21 most common disjunct species.
Variable list:
Point - Number of points assigned to either a species occurrence or a randomly generated pseudoabsence point
pres_abs - Whether species is present or not (1 for present, 0 for absent)
Species - Species that is present at that location
Common name - Common name for species present at that location
Source - Data source for species occurrence record (MNHHIS = Minnesota Department of Natural Resources, NHIC = Ontario's Natural Heritage Information Centre, GBIF = Global Biodiversity Information Facility)
Location - Province or State where location occurs
Easting - Geographic easting of point location, given in North American Lambert Conformal Conic
Northing - Geographic northing of point location, given in North American Lambert Conformal Conic
Elevation - Elevation (m) of each point above the surface of the water
Bedrock - Code for bedrock type at point location (1=Sedimentary, 2=Metamorphic, 3=Igneous,4=Igneous volcanic
Depth_10km - Average depth of water within 10 km of shore for each point
Log_euc_dist - Log of Euclidean distance between each point and edge of the water
LST - Average July Land Surface Temperature at each point
Hillman_land_temperature_raw_data.csv contains MODIS land surface temperature data for 900 randomly generated points within the study area, as well as July water surface temperature and average windspeed values associated with each point.
These data were used in a generalized linear model to examine the relationship between offshore drivers and cool shorelines.
Variable list:
Point - Number of random point assigned to each location
Easting - Geographic easting of point location, given in North American Lambert Conformal Conic
Northing - Geographic northing of point location, given in North American Lambert Conformal Conic
LST - Average July Land Surface Temperature at the point location
wst_j_25km - Average July water surface temperature within 25 km of shore for each point
mean_wind - Average July windspeed for each point
Sharing/Access information
Species occurrence records from Minnesota Department of Natural Resources (MNHIS), and Ontario's Natural Heritage Information Centre (NHIC) are provided at a coarser resolution due to the sensitive nature of rare and tracked species.
Additional species occurrence records publicly available at:
Global Biodiversity Information Facility: https://www.gbif.org/