WWF Ecoregions

Source: WWF Terrestrial Ecoregions of the World (TEOW) Year: 2001 Category: Accounting Coverage: Global Format: Boundary polygons Used in risk analysis: No (contextual layer; not used in materiality scoring)

What it shows

This layer maps the world's terrestrial ecoregions — relatively large areas of land that each contain a distinct assemblage of natural communities sharing most of their species, ecological dynamics and environmental conditions. It matters for nature-related risk because ecoregions provide a consistent biogeographic frame for situating a site within the natural community it belongs to, supporting accounting and context rather than scoring a hazard directly.

How it is built

The layer is the Terrestrial Ecoregions of the World (TEOW), a biogeographic regionalisation of the Earth's terrestrial biodiversity. It defines 867 terrestrial ecoregions, grouped into 14 broad biomes such as forests, grasslands and deserts. Each ecoregion represents the original distribution of distinct assemblages of species and communities. The dataset is supplied as mapped boundaries, with each area carrying its ecoregion and biome classification rather than a numeric risk value.

How to read it

This is a boundary layer used for context and classification. A site falls within exactly one ecoregion, which identifies the natural community and biome it belongs to. There is no higher-or-lower risk reading — the value lies in knowing which ecoregion a site sits in, for accounting and comparison against ecoregion-based delineations.

Class thresholds

This is a categorical boundary layer, not a continuous physical quantity, so it has no numeric thresholds and no risk-class table. The polygons are symbolised by biome — a 14-class qualitative typology (e.g. 1. Tropical and Subtropical Moist Broadleaf Forests, 6. Tundra, 11. Boreal forests/taiga, 13. Deserts and xeric shrublands, 14. Mangroves) — and each of the 867 ecoregions belongs to exactly one biome. There is no proximity trigger: the layer carries no risk flag and is used for accounting and context only. A site's "class" is simply the ecoregion (and biome) it overlaps.

How these thresholds were set. There are no thresholds to set. The biome and ecoregion delineations follow the WWF Terrestrial Ecoregions of the World (TEOW) classification (Olson et al., 2001); Darwin reproduces these boundaries unchanged and adds no in-house breaks.

Reference: WWF Terrestrial Ecoregions of the World (TEOW) — worldwildlife.org.

Source

Terrestrial Ecoregions of the World (TEOW), WWF — Olson et al. (2001).

Comparison with the WWF Risk Filter Suite

This is the biogeographic baseline (WWF terrestrial ecoregions, Olson 2001) that underpins WWF's ecoregion-based delineations. It is not itself a standalone Biodiversity Risk Filter risk indicator; rather, it provides the spatial framework on which several WWF area-based indicators are organised. Darwin and WWF share the same source family here.

Legend

Symbolised field: Biome

Generated from darwin/layers/layer-wwf-ecoregions.toml and risk_indicator_pairs.toml (develop).