Southern California’s endangered coastal salt marsh habitats face many issues including invasive plant species. At the Agua Hedionda Lagoon, our wetlands suffer from an abundance of invasive Algerian Sea Lavender (ASL), or Limonium ramosissimum. ASL outcompetes sensitive native plants and leaves a dense carpet. This negatively affects the wildlife that roams this salt marsh which can create problems for our endangered species that inhabit this area. A few projects have taken place to eradicate this invasive, with one currently taking place today. The most commonly used method to control these infestations was using herbicides (chlorsulfuron benzenesulfonamide). While this method was able to control the current infestation at the time, it did not control the regrowth, and it heavily damaged the soil conditions and surrounding native plants of the wetlands. Our current experiments compares the effects of black plastic vs clear plastic tarps to see which tarp will eradicate this invasive most effectively and restore the native salt marsh community.
The Black and Clear experiment has taken place over the past 6 months. There are several randomized plots that cover these dense mats of ASL, one side being covered by black plastic tarp and the other by clear. While we expect this experiment will eradicate existing Limonium, we are also looking to create soil conditions where seeds that drop cannot re-sprout into a new plant. Following the control of ASL, we plan to encourage the recolonization of native coastal salt marsh plants through seedings or plantings. Through this experiment, the Foundation is providing educational opportunities for the public, community members, and those interested in supporting local salt marshes. Our hope is to create public awareness about how ASL threatens our native habitats, so everyone can report occurrences to the Foundation or California Department of Fish and Wildlife.
The Agua Hedionda Lagoon Foundation (AHLF) is always accepting students, community members, and the public to join us in this experiment. Anyone that comes will be provided with a wonderful educational opportunity about ASL and the surrounding watershed. Those who have volunteered in the past have enjoyed connecting with others while working together to protect their local environment. If you or someone you know wants to get involved, the AHLF would love to host you for planned events or monitoring.
Figure 1: Dense stand of ASL in the Agua Hedionda Lagoon Ecological Reserve
Figure 2: Active solzarization treatment along an intertidal channel. This treatment areas measures 20 feet by 300 feet and will be installed for 4 months.
Figure 3: Active Clear vs Black Solarization treatment plot
This article was written by Sean Richardson. Sean is a research intern at the Agua Hedionda Lagoon Foundation, and a current student at California State University San Marcos. He has helped plan, implement, and monitor the Limonium project through multiple iterations and has helped get local high-school students involved with scientific research and monitoring.