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Propagule pressure from historic U.S. plant sales explains establishment but not invasion

Authors:

Matthew Fertakos

B.A. Bradley

Publication Type:
Journal Article
Year of Publication:
2024
Publisher:
Wiley
Secondary Title:
Ecology Letters
ISSN:
1461-023X, 1461-0248
DOI:
10.1111/ele.14494
Issue:
8
Volume:
27
Year:
2024

Abstract

Introduction history, including propagule pressure and residence time, has been proposed as a primary driver of biological invasions. However, it is unclear whether introduction history increases the likelihood that a species will be invasive or only the likelihood that it will be established. Using a dataset of non‐native species historically available as ornamental plants in the conterminous United States, we investigated how introduction history relates to these stages of invasion. Introduction history was highly significant and a strong predictor of establishment, but only marginally significant and a poor predictor of invasive success. Propagule pressure predicted establishment better than residence time, with species likely to be established if they were introduced to only eight locations. These findings suggest that ongoing plant introductions will lead to widespread establishment but may not directly increase invasive success. Instead, other characteristics, like plant traits and local scale processes, may better predict whether a species becomes invasive.