Making Restoration More Efficient: Testing the Contributions of Planting Diversity and Tamarisk Legacy Effects to Recovering Tidal Marshes

There is often little funding for restoration of coastal wildlife areas, once they have been cleared of non-native plant species, such as tamarisk (also known as salt cedar). The absence of follow-up, scientists say, can leave habitats vulnerable to reinvasion. This project looks at whether inexpensive strategies, such as planting native species and/or mulching with removed weeds, can speed habitat and wildlife recovery of young coastal sage scrub ecosystems in Southern California. After three years of field study, scientists report that the development of these ecosystems (progression of young to mature ecosystems) is mainly structured by the presence and quantity of living and dead plant biomass and, to a lesser degree, by the kinds of plants present. This may be due to the low primary productivity of newly cleared and replanted sites. Researchers recommend that managers prioritize planting natives with large biomass and using left-over plant litter from invasive plant eradication as mulch. Findings were shared with the public, docents and managers at NOAA’s Tijuana River National Estuarine Research Reserve and are of relevance to wetland restoration projects in the south San Diego Bay.