Invasive species are estimated to cost the United States more than $120 billion a year — more, most years, than earthquakes and floods. You cannot manage what you have not listed, so the U.S. Geological Survey keeps one list of every nonnative species known to have established itself anywhere in the country: the United States Register of Introduced and Invasive Species (US-RIIS).
What the register holds
| Records | 14,700 in version 2.0, covering 12,571 species (a species established in two places has two records) |
| Localities | three sub-lists: Alaska, Hawaii, and the lower 48 states |
| Sources | more than 5,800 — papers, books, databases, risk screenings, pest alerts and the like — with every record citing its own |
| Reviewers | more than 30 invasive-species scientists |
| Names | standardised to the Integrated Taxonomic Information System and GBIF |
| Each record | taxonomy; date of introduction where known (47% of records); whether it is invasive or only introduced; whether it was released for biological control; citations |
A species is listed for a locality only if it is nonnative everywhere in that locality and reproducing somewhere in it. The register grew out of the USGS's earlier Comprehensive List of Non-Native Species Established in Three Major Regions of the United States, and it feeds the international Global Register of Introduced and Invasive Species through the Global Biodiversity Information Facility.
Introduced, established, invasive, sleeper
How the categories nest. USGS.
- Introduced: arrived with human help — a biocontrol release, a hitchhiker on a boat, plane or car, an escaped pet or garden plant (and their parasites), something carried by tourists or shipped goods.
- Established: introduced and reproducing. Only a small share of introduced species get this far. Being established says nothing about harm: the species may be harmless, or even useful.
- Invasive: established and shown to cause, or likely to cause, harm. A much smaller share again.
- Sleeper: established and quiet for years or decades — then an environmental change sets it off. Because nobody knows which quiet species are sleepers, the register lists every established species, not only the harmful ones.
- Biocontrol species are introduced on purpose to fight an invader. They are risk-assessed first, but some have turned invasive themselves, and more could through mutation, a changing environment or a trait nobody spotted.
Hawaii stands apart
Established nonnative species per 10,000 square kilometres, by locality. USGS.
| Area (km²) | Established nonnative species | Per 10,000 km² | Mostly | |
|---|---|---|---|---|
| Lower 48 | 8,081,867 | 8,527 | about 11 | insects and flowering plants, about equally |
| Hawaii | 28,313 | 5,628 | 1,988 | insects (52%) |
| Alaska | 1,723,337 | 545 | about 3 | flowering plants (70%) |
Hawaii, the smallest of the three, has the second-largest list: for its size, it holds almost two hundred times as many established nonnative species as the lower 48 and more than six hundred times as many as Alaska. Across the whole register, 45 percent of records are insects and 39 percent flowering plants.
What it is for
- Horizon scanning: lists of species that might arrive should leave out those already here.
- Local lists: combined with species-occurrence data, the register gives a county, park or watershed its own list of established nonnatives.
- Priorities: it helps pick which potential sleepers to watch or control.
Help improve it
The USGS takes additions, corrections and suggestions, each supported by an authoritative reference, through its Science Synthesis, Analysis and Research Program.
Sources
Written from United States Register of Introduced and Invasive Species (US-RIIS), U.S. Geological Survey Fact Sheet 2024–3037, a work of the United States government in the public domain; the register itself is Simpson and others (2022), USGS data release.
이용 허락: CC0 1.0 (퍼블릭 도메인) · 출처 pubs.usgs.gov
1
0
0
0
코멘트
