Many invasive species, like garlic mustard (Alliaria petiolata), are quickly changing the world’s natural ecosystems. For this reason, invasive species are of great interest to students of ecology and evolution as well as to the broader public. Many contemporary ecological hypotheses for explaining successful biological invasions assume that plants grow more vigorous, produce more seeds, and reach higher population densities in introduced populations than in their native range. Yet there are insufficient data to test this assumption for most invasive plants because geographic variation and environmental heterogeneity within native and introduced regions requires the field sampling of many native and introduced populations, which is beyond the financial and time budgets of most research labs. Here we report on the first year of data from the Global Garlic Mustard Field Survey (www.garlicmustard.org), an ongoing global collaborative effort to quantify and compare the growth and reproductive success, population densities, and herbivore attack rates of garlic mustard (Alliaria petiolata) across its native and introduced ranges. We highlight the opportunities presented by this project for undergraduate and senior high school education, by incorporating ‘real’ scientific data, and for public outreach through the participation of ‘citizen scientists.’
Results/Conclusions
Using a relatively simple, standardized protocol and an online database we received measurements taken throughout the summer and early autumn of 2009. Samples from 64 populations in Europe and North America were provided by 23 different participants, mostly from Europe. So far, there was a disproportionate representation of European populations (55 of 64). Preliminary data on population means show strong correlations among plant height and fruit numbers, but there was no indication that introduced populations generally reached higher densities, contained larger plants or produced more seeds. However, because of the small number of North American populations, it is too early to make any generalizations. Nevertheless, reports from educators and citizen scientists involved in the project were very positive. Students were particularly motivated by the prospect of contributing to ‘real’ science while learning about invasive species and field survey methods. This project demonstrates that a mass collaboration is an efficient method for gathering data across large geographical areas, and provides exciting opportunities for education and public outreach.