![](https://sites.evergreen.edu/l3notes/wp-content/uploads/sites/528/2020/05/MSHwillows1-300x225.png)
Willows, Salix species, are a common riparian plant across the globe and are a key early successional species. Willows are known to increase water quality and stabilize banks, so it is not hard to believe they are a dominant riparian plant on the Pumice Plain of Mount St. Helens.
![](https://sites.evergreen.edu/l3notes/wp-content/uploads/sites/528/2020/05/MSHwillows2.png)
Willows are a dioecious species (they have both male and female individual shrubs) that play a vital role in understanding ecological interactions across the Pumice Plain. Our lab has documented plant sex ratios, colonization locations, and chemical differences among willow populations to understand primary succession.
![](https://sites.evergreen.edu/l3notes/wp-content/uploads/sites/528/2020/05/MSHwillows3-300x224.png)
Interestingly, a high proportion of riparian plants are dioecious. We are working to understand what advantages there are to having male and female separation along streamsides in particular. In our system, females colonize closer to streams – maybe higher resource availability for producing flowers? Stay tuned for tomorrow’s post about our latest paper regarding willow sex differences at Mount St. Helens!