spacc: Fast Spatial Species Accumulation Curves

High-performance spatial species accumulation curves using nearest-neighbor algorithms. Implements 'kNN' and 'kNCN' sampling methods with a 'C++' backend for speed. Supports Hill numbers (q=0,1,2), beta diversity partitioning (turnover/nestedness), coverage-based rarefaction and extrapolation, phylogenetic diversity (Faith's PD, mean pairwise distance, mean nearest taxon distance), functional diversity accumulation, diversity-area relationships (DAR), endemism-area curves, sampling-effort correction and fragmentation analysis, and species-area relationship (SAR) models based on extreme value theory (EVT). Multiple starting points (seeds) provide uncertainty quantification. Methods are described in 'Chao' et al. (2014) <doi:10.1890/13-0133.1>, 'Baselga' (2010) <doi:10.1111/j.1466-8238.2009.00490.x>, 'Chao' and 'Jost' (2012) <doi:10.1890/11-1952.1>, 'Faith' (1992) <doi:10.1016/0006-3207(92)91201-3>, 'Ma' (2018) <doi:10.1002/ece3.4526>, 'Borda-de-Agua' et al. (2025) <doi:10.1038/s41467-025-59239-7>, 'Hanski' et al. (2013) <doi:10.1073/pnas.1311190110>, and 'Jost' (2007) <doi:10.1890/06-1736.1>.

Version:	0.8.3
Depends:	R (≥ 3.5)
Imports:	Rcpp, RcppParallel, stats, parallel
LinkingTo:	Rcpp, RcppParallel
Suggests:	testthat (≥ 3.0.0), knitr, rmarkdown, svglite, ggplot2, cli, sf, areaOfEffect, ape, iNEXT, betapart, cluster
Published:	2026-06-20
DOI:	10.32614/CRAN.package.spacc (may not be active yet)
Author:	Gilles Colling [aut, cre, cph]
Maintainer:	Gilles Colling <gilles.colling051 at gmail.com>
BugReports:	https://github.com/gcol33/spacc/issues
License:	MIT + file LICENSE
URL:	https://gillescolling.com/spacc/, https://github.com/gcol33/spacc
NeedsCompilation:	yes
SystemRequirements:	GNU make
Language:	en-US
Citation:	spacc citation info
Materials:	README, NEWS
CRAN checks:	spacc results

Documentation:

Reference manual:	spacc.html , spacc.pdf
Vignettes:	Community Assembly and Turnover (source, R code) Diversity Accumulation (source, R code) Extrapolation and Species-Area Models (source, R code) Getting Started with spacc (source, R code) Rarefaction and Standardization (source, R code) Richness Estimation and Completeness (source, R code) Spatial Analysis: Endemism, Fragmentation, and SAR (source, R code)

Downloads:

Package source:	spacc_0.8.3.tar.gz
Windows binaries:	r-devel: not available, r-release: not available, r-oldrel: not available
macOS binaries:	r-release (arm64): spacc_0.8.3.tgz, r-oldrel (arm64): spacc_0.8.3.tgz, r-release (x86_64): not available, r-oldrel (x86_64): spacc_0.8.3.tgz

Linking:

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