The IUCN Red List of Ecosystems
(RLE) is a global standard for assessing the risk of ecosystem collapse. This
page summarizes the criteria and categories that rle-python’s metrics feed
into. The reference constants below live in rle.core.rle.
Criteria¶
An ecosystem is assessed against five criteria; the overall status is the highest risk category obtained under any single criterion.
| Criterion | Description |
|---|---|
| A | Reduction in geographic distribution |
| B | Restricted geographic distribution |
| C | Environmental degradation |
| D | Disruption of biotic processes and interactions |
| E | Quantitative analysis estimating the probability of ecosystem collapse |
rle-python computes the two spatial sub-measures of Criterion B:
EOO (Extent of Occurrence) → Criterion B1 — see Extent of Occurrence (EOO).
AOO (Area of Occupancy) → Criterion B2 — see Area of Occupancy (AOO).
Threat categories¶
import pandas as pd
from rle.core.rle import rle_categories
pd.DataFrame(rle_categories)[["name", "abbreviation", "threatened"]]The categories, from highest to lowest risk, are Collapsed (CO), Critically Endangered (CR), Endangered (EN), Vulnerable (VU), Near Threatened (NT), Least Concern (LC), plus Data Deficient (DD) and Not Evaluated (NE). CO, CR, EN, and VU are the threatened categories.
The equal-area projection¶
Both EOO area and AOO grids are computed in ESRI:54034 (World Cylindrical
Equal Area) — the equal-area projection used for RLE spatial measures, so that
areas and 10×10 km grid cells are consistent across datasets and latitudes.
For the full criteria thresholds and sub-criteria, see the IUCN RLE categories and criteria reference.