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Individual Highlight

Greenstrips in Hawaii protect high value ecosystems from fire

Photo of The greenstrip experiment within a highly flammable grassland environment surrounding an ecosystem fragment on Hawaii Island. The greenstrip experiment within a highly flammable grassland environment surrounding an ecosystem fragment on Hawaii Island. Snapshot : The purpose of the greenstrip study was to test a tool that has been used in parts of the arid continental U.S. to protect high value ecosystems from fire. Forest Service researchers wanted to identify species for restoration that would not only reduce the incidence of invasive grasses and, subsequently, fire in dryland ecosystems, but would also resist nonative species invasion once in place. They hypothesized that greenstrips with established native species would deter the reinvasion of fountain grass due to the preemption of space and resources, thereby reducing the maintenance required to remove grass fuels.

Principal Investigators(s) :
Cordell, Susan 
Research Location : Hawaii Island
Research Station : Pacific Southwest Research Station (PSW)
Year : 2017
Highlight ID : 1337

Summary

A component of Forest Service restoration of dryland ecosystems in Hawaii is to design fire reduction measures that protect remaining dry forest fragments within grass-dominated landscapes. Throughout leeward Hawaii, extensive areas of formerly dry forest have been completely converted to non-native grasslands. Managers need approaches that can enhance existing fire reduction measures to reduce the spread of large blazes across these landscapes. Greenstrip techniques are used widely in arid landscapes of the Intermountain West to limit the spread of large fires in grasslands invaded by fire-promoting alien grasses. The practice uses species with fire resistant characteristics (high water content, low levels of volatile compounds, and large leaves) to produce areas of non-flammable vegetation that disrupt fuel continuity and limit the production of fire promoting grasses. Green strips that grade into protected areas dominated by native grasses can also serve as sites of passive restoration, restoration of key ecosystem services (carbon, nutrient and water cycling), and corridors between forest fragments. Despite successes in the continental U.S., this novel approach to fuels management had not been attempted in Hawaii or the tropical Pacific. To test this concept, the scientists seeded fountain grass into plots of native species that differed in their fuel traits. The study revealed that these plots of native species significantly reduced fountain invasion compared to the control sites. Plots containing the native species Chenopodium had the lowest levels of invasion. Furthermore, Chenopodium had the highest moisture content and lowest heating value, important traits in reducing the spread of fire. Chenopodium grows quickly, grows large, and occupies space, thereby limiting reinvasion making it an excellent species to use for greenbreaks in Hawaii.

Forest Service Partners

External Partners

 
  • Cal Poly Pomona