To access BIEN data (occurrences, traits, geographic ranges and plots), use the BIEN R package (see the R BIEN publication, Maitner et al. 2018). The BIEN database provides a common schema that merges georeferenced observations of individuals and species — from herbarium specimens, vegetation inventories and regional checklists — with standardized species-level trait measurements such as plant size, growth form, wood density and specific leaf area.

BIEN 4.2 in numbers

The BIEN 4.2 release includes over 284 million primary botanical occurrence records, each a plant observation with an associated taxonomic identifier and, where available, geographic coordinates and a date.

Data type	Count (BIEN 4.2)
Total occurrence records	284,466,171
from herbarium specimens	73,927,842
from citizen science (e.g. iNaturalist)	153,551,098
from vegetation plots	17,247,823
from trait observations	380,417
from other / additional sources	39,358,991
Vegetation plots (surveyed)	363,258
Trait measurements (54 standardized traits)	25,932,454
Species with geographic range maps (Americas)	98,829
OpenRange maps (global)	289,743

Counts reflect the BIEN 4.2 release (Enquist et al. 2026; underlying data tables archived at Zenodo). Occurrence sub-rows show major sources and are not exhaustive; the “other / additional sources” row reconciles them to the total. Trait measurements and range maps are derived products. Values are version-dependent.

Standardized species counts (land plants, Embryophyta)

Species-name totals before and after taxonomic name resolution (TNRS). Ranges span alternative taxonomic backbones and TNRS settings.

Group	Species names
Total names, pre-TNRS	1,323,320
Total accepted names, post-TNRS	363,567–457,949
Angiosperms (flowering plants)	323,377–404,043
Gymnosperms (total)	1,280–1,429
conifers	856–978
non-conifers	424–451
Ferns and allies	12,102–20,921
Bryophytes	26,808–31,556

Occurrence records: herbarium and citizen science

Herbarium records and citizen-science observations (for example, iNaturalist) capture historical and contemporary plant occurrences, contributing valuable spatial and temporal insight. Major sources of compiled occurrence data in BIEN 4.2 include the aggregators GBIF and RAINBIO (Dauby et al. 2016), the Royal Botanic Garden Sydney, and NeoTropTree. BIEN includes data from 804 herbaria listed in Index Herbariorum. A full description of data contributors is provided in the BIEN 4.2 publication (Enquist et al. 2026).

Ecological plot and survey data

Plot and vegetation surveys provide systematically collected, location-specific data for plant communities — a complementary perspective to the presence-only records derived from herbarium specimens and citizen science. Unlike presence-only data, plot and survey data explicitly record species presence, abundance and true absence within a defined area, documenting taxa that were surveyed for but not observed. These explicit, effort-based absences provide a stronger basis for ecological inference than pseudo-absences generated for species distribution modelling.

Plot data in BIEN are drawn from established vegetation-monitoring programs and forest-inventory networks, including CTFS/ForestGEO (Anderson-Teixeira et al. 2015), the Carolina Vegetation Survey (Peet et al. 2012), Forest Inventory and Analysis (FIA; Gray et al. 2012), SALVIAS (Enquist & Boyle 2012), TEAM (Rovero & Ahumada 2017) and VegBank, among others. Plot sources are listed via BIEN_plot_list_datasource(), and BIEN_plot_metadata() provides detailed plot information.

Trait data

Trait observations add functional and physiological dimensions to BIEN’s records, recorded at the individual level. BIEN contains over 25 million trait records spanning 54 distinct plant traits, derived primarily from publicly available datasets from more than 800 published trait studies. These traits cover key characteristics such as leaf area, wood density and seed mass, enabling functional analyses across species and ecosystems. The most numerous trait data are: diameter at breast height (14,929,488); whole-plant height (10,167,913); whole-plant growth form (330,047; see Engemann et al. 2016); seed mass (93,543); stem wood density (39,162); and specific leaf area, SLA (51,894). Available trait data can be listed with BIEN_trait_list().

Derived products: species geographic ranges

Using the integrated observation data, BIEN provides 98,829 peer-reviewed species range maps for North and South America (Goldsmith et al. 2016; Maitner et al. 2017; Neves et al. 2021). Separately, BIEN 4.2 distributes a larger set of 289,743 modeled species range maps worldwide (112,953 of them in the Americas) through the BIEN OpenRange R package (Maitner et al. 2025). OpenRange maps are generated for terrestrial plant species with more than 15 unique records, on a 5 km grid suitable for species distribution modelling.

The Open Range maps are provided as a proof of concept, have not yet been peer-reviewed, and should be used cautiously; they include metadata for assessing quality and suitability. Range maps are available via an API and R package. Modeled ranges are statistical predictions of potential distribution, not verified occupancy.