Restoring to the future: Environmental, cultural, and management trade‐offs in historical versus hybrid restoration of a highly modified ecosystem

Abstract

With growing calls to scale up reforestation efforts worldwide, conservation managers increasingly must decide whether and how to restore highly altered ecosystems. However, empirical research on potential trade‐offs remains scarce. We use a Hawai'i watershed to demonstrate a collaborative, interdisciplinary approach to identifying synergies and trade‐offs associated with maintaining an unrestored forest, versus restoration to a historical or hybrid (native and non‐native plant species) state. We focused on restoration scenarios designed by conservation managers and measured ecological, hydrologic, and cultural outcomes they identified as important metrics of success. The hybrid restoration scenario maximized potential outcomes at moderate cost, and increased two rarely measured but often critical metrics to managers and communities: cultural value and resilience to disturbance. Hybrid restoration approaches developed collaboratively can provide a viable option for scaling up restoration in island ecosystems and other contexts where invasive species pose significant challenges and/or where community support is important.

Towards more effective integration of tropical forest restoration and conservation

“…Forest restoration is a long‐term process, and areas undergoing restoration need to be protected and sustained. In many contexts, conservation managers are faced with the urgent need to practice restoration to sustain natural ecosystems (Burnett et al., ). Within conservation areas, habitats often need to be restored following disturbances, and fragments need to be reconnected through the restoration of biological corridors.…”

“…Several serious challenges remain that will need to be resolved through focused applied research. Use of non‐native species to initiate forest restoration can be highly effective (Brockerhoff et al., ; Catterall, ), but may conflict with conservation goals if exotic species become invasive or have other negative effects on native ecosystems (Cordell, Ostertag, Michaud & Warman, ; Burnett et al., ). Large scale tree plantations can consume more water than native forests, negatively affecting native ecosystems and water supplies for people, particularly in seasonally dry tropical regions (Yu et al., ).…”

The Moku System: Managing Biocultural Resources for Abundance within Social-Ecological Regions in Hawaiʻi

“…Coastal plants tend to be distributed by ocean currents, whereas inland species tend to be distributed by wind or wing [50]. 'Ōhi'a lehua (Metrosideros polymorpha), the native tree with the highest biocultural value [51], has wind-born seeds that can be dispersed great distances. As for culturally-important trees with fleshy fruits-such as Māmaki (Pipturus spp.…”

Integrating co‐production and functional trait approaches for inclusive and scalable restoration solutions

“…These linked human-natural systems (Liu et al, 2007) contribute to social-ecological resilience (Ticktin et al, 2018) and are often based on customary knowledge-practice-belief systems developed through adaptive processes and transmitted over generations (i.e., indigenous and local knowledge; Berkes, 2008). When applied in a restoration context, agroforestry practices are often called hybrid restoration (Burnett et al, 2019;Hobbs et al, 2014), and fit under the umbrellas of the restorative continuum (Gann et al, 2019) and forest landscape restoration (Mansourian et al, 2020).…”

“…However, in certain contexts, the intersection of these two concepts (green square) holds the most potential for increasing biodiversity, ecosystem services, and human wellbeing. Practices at this intersection are often called agroforestry or hybrid restoration (Burnett et al, 2019;Hobbs et al, 2014). Placement of diversified agriculture practices along the restorative continuum varies with implementation (e.g., alley cropping that includes native plants could be considered "initiating native recovery").…”