It's All About the Wind

Have you ever wondered how mosses travel from one continent to the next?

A typical answer is that moss spores can be transported long distances by winds such as the jet-stream. You might just take that response at face value and happily go on with your day. Or you might respond, "That is an interesting hypothesis, but do you have any evidence to support it?" As a scientist my responses usually tend toward the latter, being a questioning and skeptical sort of person.
(Side Note: A hypothesis is a suggested explanation based on previous observations. You can come up with hypotheses for all sorts of phenomena, but until you have data or evidence to support your hypothesis it does not carry much weight. It just an idea.)

Well here is an interesting paper that sheds some light and data on this topic.

Jesús Muñoz, Ángel M. Felicísimo, Francisco Cabezas, Ana R. Burgaz, and Isabel Martínez. 2004. Wind as a Long-Distance Dispersal Vehicle in the Southern Hemisphere. Science Vol. 304, no. 5674, pp. 1144-1147.


In this study the authors were interested in whether the plants were more similar 1) on islands that were closer to each other or 2) on islands that were connected by 'wind-highways'. They focused on plants (and fungi) that are spread by spores. Included in the study were mosses, liverworts, lichens, and pteridophytes (aka. ferns). They collected data for these plants from different continents and islands around Antarctica. Also they used wind data to determine where the wind-highways are located.

Then comes their statistical tests and it is a little intense, just to warn you. Scientific papers published in Journals like Science and Nature are usually pretty short and can pack a punch. Figure 1 is pretty cool. It shows how connected Bouvet Island (loc. 8) is to other locations by the wind-highways.

The Take Home Message: For the mosses, liverworts, and lichens their data showed that the lands connected via the wind-highways had more similar species growing on them. This supports the hypothesis that the plants (and lichens) are traveling from one place to the next on the winds.

So the next time someone asks you how mosses travel from one continent to the next (Ok I admit you might never be asked that question, but who knows?), you can confidently state that they travel using the wind. And you can point to this paper to back you up.