The introduced and invasive flora of Bermuda
Understanding Bermuda’s Introduced and Invasive Flora: Insights from a Comprehensive 2025 Study
The resource document The introduced and invasive flora of Bermuda presents one of the most thorough analyses ever conducted on the island’s plant life. Compiled by researchers Alison Copeland and Jane Dawson, the study brings together centuries of historical records, herbarium specimens, modern literature, and garden centre surveys to produce a complete inventory of the plants that currently occur in Bermuda. This includes native species, long‑established introductions, casual escapes, naturalized species, and invasive plants.
This document is a major contribution to understanding how Bermuda’s plant communities developed, how they are changing, and which species pose the greatest risks to island biodiversity.
A Flora Dominated by Introduced Species
According to the inventory, Bermuda today contains 1,587 vascular plant species. Only 151 of these are native, while 89.8%—a total of 1,424 species—are introduced. This ratio (roughly 9 introduced species for every native species) reflects more than 400 years of human influence, trade, agriculture, ornamental gardening, and ecological disruption.
Of the introduced plants:
Many remain only in cultivation
321 have escaped cultivation and occur in the landscape
165 are fully naturalized
52 are considered invasive
These numbers reflect a long history of plant introductions, dating back to Bermuda’s early settlement in the 1600s.
How and Why These Plants Arrived
The document outlines the major pathways through which non‑native plants have entered Bermuda:
Intentional Introductions
Most introduced species arrived because people brought them in:
Ornamental plants for gardens, tourism landscapes, and landscaping
Fruit and agricultural species
Shade and windbreak trees imported after the mid‑century Cedar Blight
This intentional movement accounts for the majority of both naturalized species and invasive plants.
Accidental Introductions
Some plants arrived unintentionally:
Contaminants in imported hay, soil, and agricultural goods
Seeds carried via shipping, trade routes, or modern aircraft movements
Accidental pathways were especially significant in Bermuda’s early centuries.
The Legacy of the Cedar Blight
One of Bermuda’s most defining ecological events was the Cedar Blight of the 1940s and 1950s, which killed roughly 90% of the island’s native Bermuda cedar population over an 11‑year period.
With the landscape suddenly exposed, the government began a massive replanting effort, importing hardy, salt‑tolerant, fast‑growing species from around the world. Many of these introduced trees and shrubs—chosen for practicality rather than ecological fit—eventually escaped cultivation and established self‑sustaining populations. Today they dominate many parts of Bermuda’s woodlands.
This moment represents a turning point in Bermuda’s ecological history and greatly accelerated the spread of introduced and invasive species documented in the report.
What Counts as an Invasive Species?
In the study, a plant is considered invasive if it:
Is not native to Bermuda
Reproduces and persists in the wild
Spreads across multiple locations or habitats
Shows evidence of dominance or exclusion of native vegetation
Using this definition, the study identifies 52 invasive plant species currently established on the island.
These include a range of trees, shrubs, grasses, vines, ferns, and aquatic species. Many were originally brought in as ornamentals or for landscaping. Others arrived accidentally or were intentionally released for coastal stabilization or agricultural uses.
Where These Plants Come From
Bermuda’s invasive flora originates from several global regions, reflecting both historical trade patterns and modern horticultural trends. The most common source regions include:
Temperate Asia
Tropical Asia
Africa
The Americas
Australasia
The broad geographic origins demonstrate how global plant movement—especially ornamental horticulture—has shaped Bermuda’s environment.
Why This Document Matters
This resource provides essential insight into:
How Bermuda’s plant communities have evolved over time
Which species are most likely to become naturalized or invasive
How trade, landscaping practices, and tourism development have shaped today’s ecosystems
How future biosecurity and plant‑import policies can be strengthened
For environmental managers, horticulturists, conservationists, and educators, this inventory serves as a baseline reference for understanding Bermuda’s ecological challenges and planning effective invasive‑species management.
A Tool for the Future
By creating a standardized classification of plant origins, introduction status, growth forms, and invasion stages, the authors have produced a foundation for ongoing monitoring. This allows new introductions to be flagged early, naturalized species to be tracked as they spread, and invasive species to be managed more effectively.
For the public, the report underscores the importance of thoughtful plant selection, responsible gardening, and environmental awareness. For a small island like Bermuda, every introduction matters.
