DOI: 10.5061/dryad.79cnp5j3v
title: The Andes of Colombia and Ecuador as a barrier to fern and lycophyte species from Mesoamerica

description: We compiled a list of the fern and lycophyte species that occur in
 Mesoamerica and extend into Colombia and Ecuador where they are restricted
 to the western side of the Andes; that is, they only occur west of the
 crest of the easternmost cordillera and are absent from that cordillera’s
 eastern slope and in adjacent Amazonia. We found 130 species with this
 Mesoamerican and west-of-the-eastern-cordillera distribution. Those 130
 species constitute 7% of the total 1805 fern and lycophyte species that
 have been recorded west of the crest of the easternmost cordillera in
 Colombia and Ecuador. All 130 species had elevation ranges with midpoints
 lying in low (0–900 m) or middle (900–3000 m) elevations, and none were
 above 3000 m. This suggests the cordilleras have acted as elevational
 barriers. We also investigated the blockage of these 130 species by each
 of the Andean cordilleras. We found that 74 (57%) of the 130 species were
 limited eastward by the western cordillera, 15 (11%) by the central
 cordillera (this cordillera in Colombia only), and 41 (32%) by the eastern
 cordillera. If estimates of endemics to the western Andean region are
 considered, then at least 20–22% of all fern and lycophyte species are
 restricted west of the crest of the easternmost cordillera. Although
 usually exhibiting larger geographic distributions compared to
 angiosperms, fern and lycophyte species may show significant geographic
 restriction by mountain ranges.
description: # The Andes of Colombia and Ecuador as a barrier to fern and lycophyte
 species from Mesoamerica
 [https://doi.org/10.5061/dryad.79cnp5j3v](https://doi.org/10.5061/dryad.79cnp5j3v) In this repository are the zipped shapefiles, custom R-script and species lists related to Morris & Moran 2025.  available files: •       Zipped shapefiles for Regions A, B, and C of Colombia and Ecuador •       R script used to calculate the total number of fern and lycophyte species in Regions A, B, and C •       Cleaned list of species present in Regions A, B, and C of Colombia and Ecuador as a .csv ## Description **total_species_calculation_Morris__Moran_2024.R** * The R script is linked to the shapefiles. * The R script takes a downloaded occurrence dataset from [GBIF](https://www.gbif.org/) , cleans the records, and subsets the occurrences using the shapefiles. * The working directory in R should contain the shapefiles for the script to work properly.   **Polygons A, B, C, and ABC** * Each zipped file contains the shapefile for that polygon. * This can be used in mapping softwares such as ArcGIS or can be referenced in an R-script, as it was used for this project.  * The shapefile folders should be in the same directory as the R script in order for the R script to work properly. * The regions correspond to the regions illustrated in Figure 1 of the publication. Polygon ABC is all three regions combined into 1 polygon. **SpeciesListPolygonsABC.csv** * This .csv file contains the names of all 1775 species found in regions A, B or C from GBIF records (see Figure 1) after cleaning.  * These names have been curated and confirmed by taxonomic experts, including the authors of the publication.  * The CollectionCount column is the number of occurrences for each taxon, after cleaning.  * Column D summarizes the total number of fern species and lycophyte species found in the region, including the 30 species not in GBIF but known (via herbarium specimens) to occur in the region.  ## Sharing/Access information Data is available here without restrictions ## Code/Software Analyses of the occurrence records were done in R version 4.3.2 shapefiles were created using ESRI ArcGIS Pro version 3.2.2