An interdisciplinary research team from the University of Hawaiʻi at Mānoa and the National Tropical Botanical Garden ( NTBG ) demonstrated how collaboratively-developed forest restoration in Limahuli Garden and Preserve can increase community benefits and improve resilience at lower cost than standard forest restoration programs. Because conservation managers are increasingly faced with making restoration decisions constrained by multiple goals and limited budgets, the research team collaborated with conservation professionals at Limahuli to co-design research that will directly inform adaptive management.

Specifically, authors of “Restoring to the future: Environmental, cultural, and management trade‐offs in historical versus hybrid restoration of a highly modified ecosystem” in Conservation Letters asked how manager-defined ecological, hydrologic and cultural metrics of success and long-term management costs vary across different restoration strategies.

The researchers focused on the ahupuaʻa of Hāʻena on Kauaʻi Island, and evaluated unrestored forest and forests restored to different states—ranging from a pre-human arrival state, to a “hybrid” state that includes mixes of native and non-native species of cultural importance. Their study site was Limahuli Valley, a 400-hectare nature preserve managed by NTBG in the most biodiverse ecoregion of the Hawaiian archipelago, which is home to dozens of endangered plants and birds found nowhere else on earth. They found that restoring forest to a hybrid state provided many of the same services that a restored ‘pre-human’ state can provide, but at a much lower cost. They also found it increased two important services: cultural value and resilience to disturbance such as hurricanes.

Kimberly Burnett, specialist with the UH Economic Research Organization ( UHERO ) and lead author of the study, said, “While conservation managers cannot make realistic decisions without considering costs, these type of tradeoff analyses are rare in restoration research. Our study provides a framework to consider these costs and benefits, while providing specific management direction for Limahuli and generalizable lessons for restoration strategies around the world.”

Tamara Ticktin, co-author on the study, professor of botany and principal investigator on the National Science Foundation grant that funded the research, added, “Like any restoration strategy, hybrid forest restoration also has its limitations. Our study concluded that hybrid forests can be an excellent strategy within a landscape mosaic that also includes more expensive restoration strategies needed to preserve the most endangered species. The value of our multidisciplinary approach is that it provides a powerful tool for resource managers to take into consideration the different metrics that are important to them, and to make more informed decisions about what that landscape mosaic of restored forest could look like.”