Authors: Rebecca Ostertag and Nicole DiManno

In this age of the Anthropocene, restoration to a previous reference condition may not be feasible in all situations, due to lack of information, organization, invasive species, or climate change. When site improvement and enhanced ecosystem services are desirable, a valuable option may be hybrid ecosystems, in which species are planted together even if they did not coexist together historically. The Hawaiian Islands are known for a prevalence of non-native species, a portion of which are highly invasive and degrade ecosystems structure and function. A restoration experiment in an invaded lowland wet forest in Hilo, Hawaiʻi tests four different species combinations (teams)—using both native species and non-native non-invasive species—that were carefully chosen using functional trait theory. The teams were followed for five years to determine whether hybrid ecosystems can meet the objectives of increased carbon storage, regeneration of native biodiversity, resistance from invasive species, and low levels of maintenance. Because hybrid ecosystems represent a paradigm shift in restoration planning, opinions about the value and functions of non-native species will be challenged. This module ponders how supporting tropical forest recovery in the Anthropocene engenders hard decisions that restoration practitioners must confront about what species belong in an ecosystem and which tradeoffs are acceptable, in terms of biological desires and economic realities. This module works best with a class discussion component.