While biological invasions have the potential for large negative impacts on local communities and ecological interactions, increasing evidence suggests that species once considered major problems can decline over time. Declines often appear driven by natural enemies, diseases, or evolutionary adaptations that selectively reduce populations of naturalized species and their impacts.  Using permanent long-term monitoring locations, we document declines of Alliaria petiolata (garlic mustard) in eastern North America with distinct local and regional dynamics as a function of patch residence time.  Projected site-specific population growth rates initially indicated expanding populations, but projected population growth rates significantly decreased over time and at the majority of sites fell below 1, indicating declining populations. Negative soil feedback provides a potential mechanism for the reported disappearance of ecological dominance of A. petiolata in eastern North America.

Standardized long-term data collection in permanent 0.5m² quadrats using multiple locations at a site with sites rangin from New Jersey to Illinois in eastern North America.  Duration of data collection varied by site but in the longest sites it spanned over a decade. Data were collected on important demographic parameters for garlic mustard (number of seedlinsg or mature plants, etc.) to allow building demographic models to forecast population trends.

The data we provide in excel is the raw data and all column headings are explained in a separate excel file called metadata.