Seed Bank Expression

Control and eradication of non-native invasive plants in forest ecosystems is a process that can take years. Under the rapid detection / early response framework, invasives are spotted in the very early stages of infestation, allowing the issue to be tackled with relative ease. In most cases, however, we don’t have this luxury. Infestations are often only noticed or recognized as a problem after the invasive plants have established multiple generations, producing seeds year after year and building up an unseen seed bank below the soil’s surface. This reservoir of seeds awaits the right conditions to germinate, sprout, and eventually go on to produce seeds of their own. 

One strategy that we have found to be valuable in this latter case involves encouraging seed bank expression before performing a thorough treatment of the understory. Seed bank expression means that all or most of the underground seed bank has germinated, sprouted, and “expressed” itself in the form of aboveground plants. The seeds of many invasive plants can stay dormant in the soil for multiple years. For instance, common buckthorn seeds can remain viable for up to five years, emphasizing the need for patience in such scenarios (https://www.ontarioinvasiveplants.ca/wp-content/uploads/2016/06/OIPC_BMP_Buckthorn.pdf). 

These photos were taken from one of our ongoing projects, where we were able to successfully halt seed production in the past two years by killing all of the large, seed-producing trees. The results in the understory, after just two years of seed bank expression, are astonishing. At this point we can say that much of the seed bank has expressed itself, and we can now perform a thorough understory treatment to kill the new seedlings before they ever get to seed. 

If you or someone you know has an infestation of non-native invasive plants, don’t wait! Contact Riverscape Ecology today to find out how we can help.