---
title: "Part 0: Getting Started"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Part 0: Getting Started}
  %\VignetteEngine{knitr::rmarkdown_notangle}
  %\VignetteEncoding{UTF-8}
---

## Transparent setup

```{r setup, include = TRUE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.width = 7,
  fig.height = 5,
  purl = FALSE
)

ext_file <- function(...) {
  path <- system.file("extdata", ..., package = "gbif.range")
  if (nzchar(path)) {
    return(path)
  }
  normalizePath(file.path("..", "inst", "extdata", ...), mustWork = TRUE)
}

library(gbif.range)
```

## Scope

This vignette gives a high-level tour of `gbif.range` and covers the three most
common single-species workflows end to end:

- a **terrestrial** example (*Panthera tigris*) using `get_status()`,
  `get_gbif()`, and `get_range()` with the packaged *eco_terra* ecoregions,
- a **marine** example (*Delphinus delphis*) demonstrating the `occ_samp`
  sampling argument for very large record volumes,
- a **local** example (*Arctostaphylos alpinus* in the European Alps) showing
  how to build a custom ecoregion layer with `make_ecoreg()`.

For deeper coverage of each topic, see the three focused vignettes:

- `vignette("gbif-retrieval-and-taxonomy", package = "gbif.range")` — taxonomy,
  filtering, thinning, and DOI generation,
- `vignette("ecoregion-constrained-range-inference", package = "gbif.range")` —
  `get_range()` in depth, packaged and custom ecoregions, evaluation,
- `vignette("large-downloaded-gbif-tables", package = "gbif.range")` — the
  disk-based batch workflow for large multi-species GBIF exports.

## Installation

```{r install, eval = FALSE}
install.packages("gbif.range")
library(gbif.range)
```

Install with `build_vignettes = TRUE` so that `browseVignettes("gbif.range")`
finds all workflow vignettes after installation.

## Package overview

`gbif.range` provides a complete workflow from raw GBIF records to
ecologically informed range maps. Spatial operations throughout rely on the
`terra` package (Hijmans 2022). The main functions are:

| Function | Role |
|---|---|
| `get_status()` | Inspect the GBIF backbone taxon concept, synonyms, infra-specific taxa, and IUCN status |
| `get_gbif_count()` | Estimate record volume before downloading |
| `get_gbif()` | Credential-free, synonym-aware occurrence download with 13 post-processing filters |
| `obs_filter()` | Grid-based occurrence thinning |
| `get_range()` | Ecoregion-constrained range inference |
| `merge_range()` | Aggregate range geometry into one feature or by polygon id |
| `read_ecoreg()` | Download and read packaged ecoregion files |
| `make_ecoreg()` | Build a custom ecoregion layer from any set of spatial raster layers |
| `make_tiles()` | Generate GBIF-ready `POLYGON()` tiles for explicit tiling workflows |
| `get_doi()` | Create a citable GBIF-derived DOI for downloaded records |
| `evaluate_range()` | Validate a range map against user-supplied distribution data |
| `cv_range()` | Cross-validate a `get_range()` output against its occurrence data |
| `split_gbif_by_species()` | Stream a large downloaded GBIF table and write one file per species |
| `species_csvs_to_ranges()` | Build one range per species from per-species occurrence files |
| `read_range_rds()` | Read a `.rds` range file saved by `species_csvs_to_ranges()` |

## Terrestrial example: *Panthera tigris*

### Inspect the taxon concept

Before downloading, `get_status()` shows which accepted name and synonyms
`get_gbif()` will use internally, and retrieves the current IUCN Red List
status from the GBIF backbone.

```{r get-status-tiger, eval = FALSE}
# Accepted name and direct synonyms only (the default)
get_status("Panthera tigris")

# Also include infra-specific taxa (subspecies, varieties) —
# these are the keys actually used by get_gbif()
get_status("Panthera tigris", level = "children")
```

`level = "all"` additionally returns alternative name representations for
manual inspection, but those extra entries are not used for occurrence
retrieval.

### Download occurrences

```{r get-gbif-tiger, eval = FALSE}
obs_pt <- get_gbif(sp_name = "Panthera tigris")
```

`get_gbif()` works without GBIF credentials. It is built on top of `rgbif`
(Chamberlain et al. 2022) and harmonizes the query to the accepted GBIF taxon
key, applies a dynamic moving-window tiling strategy when the geographic extent
contains more than 10,000 records, and runs 13 configurable post-processing
filters based on custom logic and `CoordinateCleaner` (Zizka et al. 2019).
The function originates from the occurrence retrieval workflow first employed
in Chauvier et al. (2021, *Ecological Monographs*).

```{r plot-tiger-occ, eval = FALSE}
countries <- terra::vect(
  ext_file("world_countries.shp")
)
terra::plot(countries, col = "#bcbddc")
graphics::points(obs_pt[, c("decimalLongitude", "decimalLatitude")],
       pch = 20, col = "#99340470", cex = 1.5)
```

```{r fig-tiger-occ, echo = FALSE, out.width = "100%"}
knitr::include_graphics("../man/figures/Part0_plot1.png")
```

Note that some records of likely captive individuals remain (e.g., in Europe,
the U.S., and South Africa) — the default `CoordinateCleaner`-based filters do
not remove all zoo or botanical garden records. The `get_gbif()` help page
documents the available post-processing arguments for stricter cleaning.

### Build the range map

`get_range()` implements the ecoregion-constrained range inference algorithm
originally developed by Hagen et al. (2019) and can accept any types of
observations as long as 'decimalLongitude`, `decimalLatitude` columns are valid:

```{r range-tiger, eval = FALSE}
# Download and read the packaged terrestrial ecoregions (The Nature Conservancy 2009)
eco_terra <- read_ecoreg(ecoreg_name = "eco_terra", save_dir = tempdir())

# Range (default)
range_tiger <- get_range(
  occ_coord = obs_pt,
  ecoreg = eco_terra,
  ecoreg_name = "ECO_NAME",
  degrees_outlier = 5,
  clust_pts_outlier = 4,
  format = "SpatVector"
)

# Plot
terra::plot(countries, col = "#bcbddc")
terra::plot(range_tiger$rangeOutput, col = "#238b45",
            add = TRUE, axes = FALSE, legend = FALSE)
```

```{r fig-tiger-merged, echo = FALSE, out.width = "100%"}
knitr::include_graphics("../man/figures/Part0_plot2.png")
```

`degrees_outlier` and `clust_pts_outlier` control how isolated clusters of
observations are handled before the ecoregion lookup. Increasing either
parameter produces a more conservative range that excludes more distant
clusters; the defaults (~550 km and ~440 km respectively) already removed the
most obvious anomalies in Europe, the U.S., and South Africa for
this example. Note that default parameters are usually recommended for
creating range at the global scale — see the *"Tuning the main range arguments"*
section of `vignette("ecoregion-constrained-range-inference")`.

Optionally, `format` controls the geometry type of the output range. Three are
available: `SpatVector`, `sf`, and `SpatRaster`. If polygons, then `merge_range`
can be optionally used to aggregate the geometry:

```{r merge-range, eval = FALSE}
plot(merge_range(range_tiger), col = "#238b45")
```

```{r fig-merge-range, echo = FALSE, out.width = "50%"}
knitr::include_graphics("../man/figures/Part0_plot3.png")
```

By default, the range output has its number of features defined by `ecoreg_name`
for exploratory purposes. If not needed, `merge_range` can be applied to
dissolve them into a single polygon.

## Marine example: *Delphinus delphis*

For species with very large GBIF footprints, `occ_samp` extracts a subsample
of *n* observations per geographic tile rather than retrieving all available
records. This trades completeness for speed and is appropriate for exploratory
analysis or very broad-extent range inference.

**Note:** that the download takes longer without `occ_samp`. Although giving
**less precise observational distribution**, `occ_samp` allows extracting a
**subsample of *n* GBIF observations** per created tile over the study area.

```{r marine-example, eval = FALSE}
# 1000 observations per tile — faster, but less spatially complete
obs_dd <- get_gbif("Delphinus delphis", occ_samp = 1000)

# level = "all" includes doubtful or provisional names for manual inspection
get_status("Delphinus delphis", level = "all")

# Build range maps at three levels of ecoregion detail
eco_marine <- read_ecoreg(ecoreg_name = "eco_marine", save_dir = tempdir())
range_dd1 <- get_range(obs_dd, eco_marine, "ECOREGION")
range_dd2 <- get_range(obs_dd, eco_marine, "PROVINCE")
range_dd3 <- get_range(obs_dd, eco_marine, "REALM")

# Plot the coarsest result
terra::plot(countries, col = "#bcbddc")
terra::plot(range_dd1$rangeOutput, col = "#238b45",
            add = TRUE, axes = FALSE, legend = FALSE)
graphics::points(obs_dd[, c("decimalLongitude", "decimalLatitude")],
       pch = 20, col = "#99340470", cex = 1)
```

```{r fig-dolphin, echo = FALSE, out.width = "100%"}
knitr::include_graphics("../man/figures/Part0_plot4.png")
```

The three range levels (`"ECOREGION"`, `"PROVINCE"`, `"REALM"`) produce similar
results here because most observations are near the coast. Because only a
marine subsample was retrieved, the resulting map closely follows the GBIF
sampling pattern. Increasing or removing `occ_samp` would produce a more complete
distributional estimate.

## Available ecoregions

The `ecoreg_list` object lists all ecoregion files that can be downloaded with
`read_ecoreg()`:

```{r ecoreg-list, eval = FALSE}
ecoreg_list
```

The packaged ecoregion layers and their available spatial levels are:

| Layer | `ecoreg_name` values | References |
|---|---|---|
| `eco_terra` — terrestrial | `"ECO_NAME"`, `"WWF_MHTNAM"`, `"WWF_REALM2"` | Olson et al. (2001); The Nature Conservancy (2009) |
| `eco_marine` — marine | `"ECOREGION"`, `"PROVINCE"`, `"REALM"` | Spalding et al. (2007); The Nature Conservancy (2012) |
| `eco_hd_marine` — high-detail marine coastlines | `"ECOREGION"`, `"PROVINCE"`, `"REALM"` | Spalding et al. (2007, 2012); The Nature Conservancy (2012) |
| `eco_fresh` — freshwater | `"ECOREGION"` | Abell et al. (2008) |

Beyond the packaged layers, `get_range()` accepts any polygon object as
`ecoreg` — including habitat maps, expert-defined units, or bioregions from
species composition data (Denelle et al. 2025) — as long as it has a named
character column for `ecoreg_name`. See Part 1 for full details on both.

## Local example: custom ecoregions with `make_ecoreg()`

For regional analyses the packaged ecoregions may be too coarse.
`make_ecoreg()` builds a custom ecoregion layer by k-medoid-based clustering of one
or more spatial raster layers (Chauvier et al. 2021, *Global Ecology and Biogeography*).
Any spatially structured raster variable can be used as input — not just
climate layers.

The example below first illustrates what a `make_ecoreg()` output looks like
with 10 classes over the European Alps, using two CHELSA bioclimatic layers
(Karger et al. 2017) — mean annual temperature (bio1) and annual precipitation
(bio12) at 5 × 5 km resolution:

```{r make-ecoreg-plot, eval = FALSE}
bio <- terra::rast(ext_file("rst.tif"))
eco_eg <- make_ecoreg(env = bio, nclass = 10)
terra::plot(eco_eg, col = grDevices::rainbow(10))
```

```{r fig-ecoreg, echo = FALSE, out.width = "70%"}
knitr::include_graphics("../man/figures/Part0_plot5.png")
```

For a real regional analysis, more classes are appropriate. The full workflow
with 200 classes and *Arctostaphylos alpinus*:

```{r custom-ecoreg, eval = FALSE}
# Two CHELSA bioclimatic layers for the European Alps at 5 x 5 km resolution
bio <- terra::rast(ext_file("rst.tif"))

# 200 ecoregion classes
my_eco <- make_ecoreg(env = bio, nclass = 200)

# Download Arctostaphylos alpinus within the Alps bounding box
shp_lonlat <- terra::vect(
  ext_file("shp_lonlat.shp")
)
obs_arcto <- get_gbif(
  sp_name = "Arctostaphylos alpinus",
  geo     = shp_lonlat,
  grain   = 1            # 1 km precision — appropriate for a local extent
)

# Build the range (always use 'EcoRegion' as ecoreg_name for make_ecoreg() output)
range_arcto <- get_range(
  occ_coord            = obs_arcto,
  ecoreg               = my_eco,
  ecoreg_name          = "EcoRegion",
  res                  = 0.05,        # 5 x 5 km output resolution
  degrees_outlier      = 5,
  clust_pts_outlier    = 4,
  buff_width_point     = 4,
  buff_incrmt_pts_line = 0.5,
  buff_width_polygon   = 4,
  format = "SpatRaster"
)

# Plot
alps_shp <- terra::crop(countries, terra::ext(bio))
terra::plot(alps_shp, col = "#bcbddc")
terra::plot(range_arcto$rangeOutput,
  add = TRUE,
  col = "darkgreen",
  axes = FALSE,
  legend = FALSE
)
graphics::points(obs_arcto[, c("decimalLongitude", "decimalLatitude")],
       pch = 20, col = "#99340470", cex = 1)
```

```{r fig-arcto, echo = FALSE, out.width = "70%"}
knitr::include_graphics("../man/figures/Part0_plot6.png")
```

Three design choices matter here. First, `grain = 1` keeps only records with
coordinate uncertainty ≤ 1 km; at larger scales the default 100 km grain is
appropriate, but for a small alpine extent it would retain too many imprecise
records. Second, the `res` argument sets the output raster resolution, which can
be as fine as the input environmental layers allow. Third, the outlier and
buffer parameters above were left at their defaults, which is appropriate here
because *Arctostaphylos alpinus* occurs broadly across the Alps and Europe
wherever conditions are suitable. For species with a more spatially
restricted or biogeographically constrained distribution, these parameters
often need tightening — see the *"Tuning the main range arguments"* section of
`vignette("ecoregion-constrained-range-inference")` for a worked example.

## Large downloaded GBIF tables

For multi-species analyses where GBIF data have already been downloaded as a
single large file, `gbif.range` provides a disk-based batch workflow that
avoids loading the full table into memory:

```{r disk-workflow, eval = FALSE}
gbif_file <- ext_file("occ_example_4sps.csv")
split_dir <- file.path(tempdir(), "gbif_split")
range_dir <- file.path(tempdir(), "gbif_ranges")

# 1. Split the large table into one file per GBIF taxon key
split_summary <- split_gbif_by_species(
  input_file = gbif_file,
  outdir     = split_dir,
  chunk_size = 100,
  sep_in     = "\t",
  sep_out    = "\t",
  overwrite  = TRUE,
  verbose    = FALSE
)

# 2. Build one range per species from the per-species files
range_summary <- species_csvs_to_ranges(
  species_dir   = split_dir,
  ecoreg        = "eco_terra",
  ecoreg_name   = "ECO_NAME",
  outdir        = range_dir,
  range_save_as = "rds",
  overwrite     = TRUE,
  verbose       = FALSE
)

# 3. Read one saved range back from disk
rg <- read_range_rds(range_summary$range_file[1])
terra::plot(merge_range(rg), col = "darkblue")
```

```{r fig-disk, echo = FALSE, out.width = "50%"}
knitr::include_graphics("../man/figures/Part0_plot7.png")
```

## Next steps

The three focused vignettes cover each part of the workflow in depth:

- Part 1: `vignette("gbif-retrieval-and-taxonomy", package = "gbif.range")` —
  `get_status()`, `get_gbif_count()`, `get_gbif()`, `obs_filter()`,
  `make_tiles()` and `get_doi()`.
- Part 2: `vignette("ecoregion-constrained-range-inference", package = "gbif.range")` —
  `get_range()`, the packaged and custom ecoregion options, `merge_range()`,
  and the evaluation functions `cv_range()` and `evaluate_range()`.
- Part 3: `vignette("large-downloaded-gbif-tables", package = "gbif.range")` —
  the disk-based batch workflow built around `split_gbif_by_species()`,
  `species_csvs_to_ranges()` and `read_range_rds()`.

## References

Abell, R., Thieme, M. L., Revenga, C., Bryer, M., Kottelat, M., Bogutskaya, N., … Petry, P. (2008). Freshwater ecoregions of the world: a new map of biogeographic units for freshwater biodiversity conservation. *BioScience*, 58(5), 403–414. https://doi.org/10.1641/B580507

Chamberlain, S., Oldoni, D., & Waller, J. (2022). rgbif: interface to the global biodiversity information facility API. https://doi.org/10.5281/zenodo.6023735

Chauvier, Y., Zimmermann, N. E., Poggiato, G., Bystrova, D., Brun, P., & Thuiller, W. (2021). Novel methods to correct for observer and sampling bias in presence-only species distribution models. *Global Ecology and Biogeography*, 30(11), 2312–2325. https://doi.org/10.1111/geb.13383

Chauvier, Y., Thuiller, W., Brun, P., Lavergne, S., Descombes, P., Karger, D. N., Renaud, J., & Zimmermann, N. E. (2021). Influence of climate, soil, and land cover on plant species distribution in the European Alps. *Ecological Monographs*, 91(2), e01433. https://doi.org/10.1002/ecm.1433

Denelle, P., Leroy, B., & Lenormand, M. (2025). Bioregionalization analyses with the bioregion R package. *Methods in Ecology and Evolution*, 16, 496–506. https://doi.org/10.1111/2041-210X.14496

Hagen, O., Vaterlaus, L., Albouy, C., Brown, A., Leugger, F., Onstein, R. E., Novaes de Santana, C., Scotese, C. R., & Pellissier, L. (2019). Mountain building, climate cooling and the richness of cold-adapted plants in the Northern Hemisphere. *Journal of Biogeography*, 46(8), 1792–1807. https://doi.org/10.1111/jbi.13653

Hijmans, R. J. (2022). terra: Spatial Data Analysis. R package version 1.6-7. https://CRAN.R-project.org/package=terra

Karger, D. N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R. W., Zimmermann, N. E., Linder, H. P., & Kessler, M. (2017). Climatologies at high resolution for the earth's land surface areas. *Scientific Data*, 4, 170122. https://doi.org/10.1038/sdata.2017.122

Olson, D. M., Dinerstein, E., Wikramanayake, E. D., Burgess, N. D., Powell, G. V. N., Underwood, E. C., … Kassem, K. R. (2001). Terrestrial ecoregions of the world: a new map of life on Earth. *BioScience*, 51(11), 933–938. https://doi.org/10.1641/0006-3568(2001)051[0933:TEOTWA]2.0.CO;2

Spalding, M. D., Fox, H. E., Allen, G. R., Davidson, N., Ferdaña, Z. A., Finlayson, M., … Robertson, J. (2007). Marine ecoregions of the world: a bioregionalization of coastal and shelf areas. *BioScience*, 57(7), 573–583. https://doi.org/10.1641/B570707

Spalding, M. D., Agostini, V. N., Rice, J., & Grant, S. M. (2012). Pelagic provinces of the world: a biogeographic classification of the world's surface pelagic waters. *Ocean & Coastal Management*, 60, 19–30. https://doi.org/10.1016/j.ocecoaman.2011.12.016

The Nature Conservancy (2009). Global Ecoregions, Major Habitat Types, Biogeographical Realms and The Nature Conservancy Terrestrial Assessment Units. Cambridge (UK): The Nature Conservancy. https://geospatial.tnc.org/datasets/b1636d640ede4d6ca8f5e369f2dc368b/about

The Nature Conservancy (2012). Marine Ecoregions and Pelagic Provinces of the World. Cambridge (UK): The Nature Conservancy. https://habitats.oceanplus.org

Zizka, A., Silvestro, D., Andermann, T., Azevedo, J., Duarte Ritter, C., Edler, D., … Antonelli, A. (2019). CoordinateCleaner: Standardized cleaning of occurrence records from biological collection databases. *Methods in Ecology and Evolution*, 10(5), 744–751. https://doi.org/10.1111/2041-210X.13152
