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climniche

Climate change becomes exposure when it is read against the climate a species already occupies. climniche measures where each projected climate moves in that niche: how far, toward or away from the realised niche centre, into a different climatic combination, or beyond the current boundary.

R-CMD-check CRAN status pkgdown

Website: https://bohao0813.github.io/climniche/

Niche climate exposure concept
Niche climate exposure concept

Installation

Install the CRAN release:

install.packages("climniche")

Install the development version from GitHub:

install.packages("remotes")
remotes::install_github("Bohao0813/climniche")

Decomposition

climniche reports four quantities from one niche-relative decomposition. Field names in fitted R objects use snake_case; figures and reports use the formal names below.

  • Climatic Displacement (climate_change_amount): distance between current and future conditions in the fitted sensitivity weighted climatic space.
  • Niche Distance Shift (niche_distance_change): signed change in distance from the current realised climatic niche centre.
  • Climatic Reconfiguration (climate_reconfiguration): non radial component of climatic displacement. It is derived from Climatic Displacement and Niche Distance Shift rather than estimated independently.
  • Niche Boundary Exceedance (niche_boundary_exceedance): positive excess beyond the chosen weighted quantile of current reference-cell distances from the realised niche centre.

Basic use 

library(climniche)

sim <- simulate_climniche()

fit <- fit_climniche(
  current = sim$current,
  future = sim$future_away,
  occupied = sim$occupied,
  center = sim$center,
  sensitivity = sim$sensitivity
)

climniche_summary(fit)
climniche_report(fit, species = "example species")
plot_climniche_summary_figure(fit)

For raster workflows, use fit_climniche_raster() or fit_climniche_terra(). The reference layer can be binary or continuous. Continuous SDM suitability values are treated as weights; occupied_threshold removes low-suitability cells but keeps the remaining suitability values continuous. Use domain to restrict the analysis to the accessible area or study region. Map functions can draw sf, Spatial, SpatVector or x-y boundary objects through study_region.

Worked example

The Examples page uses European anchovy in the Mediterranean Sea. OBIS occurrences and Bio-ORACLE v3 predictors are used to prepare a presence-background SDM. The SDM cutoff is selected by maximum test-set TSS; cells below the cutoff are removed from the reference set, and cells above the cutoff keep their continuous suitability values as reference weights. The example then maps the four exposure metrics inside current suitable habitat under SSP2-4.5.

Contributor

Contributions are welcome. Please make a pull request or contact .