- Author: Elise S Gornish
In California, a general requirement of plant species used for revegetation and restoration projects is its classification as a native species. However, the high cost of native plant materials is one of the dominant obstacles to effective revegetation nationwide. The exclusive use of native plants may also inhibit revegetation success because natives may not compete well with existing invasive species, and may not establish as readily as non-natives. As a result, in some cases, non-native plants could provide greater management value than natives for revegetation and restoration projects. For example, rapid establishment rates of non-natives in high-stress environments can also provide utility for erosion control or revegetating landscapes exposed to intense wildfire. Many practitioners now appear to be more willing to consider non-native species in revegetation projects. As expected, however, there is heated debate as to the overall environmental benefit and ecological ethics associated with using non-natives for revegetation projects.
In California, where over 1,500 non-native species have become naturalized or invasive in agricultural and natural areas, discussions concerning the potential role of non-natives for revegetation are particularly intense due to the well-recognized ecological and economic impacts of weedy species. Given that approaches to revegetation may be shifting, the development of a general understanding of how California's diverse land management community currently considers non-native plant species for ecological revegetation efforts would be helpful as a foundation for discussion of the potential role of non-native plant species for revegetation.
In an upcoming article available in the journal California Agriculture, researchers conducted a survey of 192 California restoration stakeholders that work in a variety of habitats to understand decision-making strategies involving the use of non-native plant species in revegetation projects. They found that a large portion (42%) of the respondents consider non-natives for their projects, and of survey respondents who do not currently use non-natives in vegetation rehabilitation, almost half indicated that they would consider using non-natives in the future. Across habitats, the dominant value of non-natives for vegetation rehabilitation was found to be erosion control, and many respondents noted the high cost and unavailability of natives as important drivers of non-native use in revegetation projects. Exploring the use of non-native species in revegetation involves both the philosophical aspects of accepting the role of non-native plants in ecosystems as well as practical considerations of objectives, availability and cost. This survey illuminates current practices of those working in restoration in California, and these data will support further discussion about the role of non-native plants in restoration.