Fantasy football for community ecologists: Building hybrid ecosystems in Hawaiian lowland wet forests

Background/Question/Methods

As novel assemblages of native and non-native species become increasingly common globally, many conservation and restoration efforts have concentrated on the removal of exotic (and often invasive) species. However, in some cases, removing non-native species is no longer economically or ecologically feasible. Furthermore, some of these non-native, non-invasive species may be providing important ecosystem goods and services, including benefits to native species. In Hawai’i, the remnant lowland wet forest communities contain a mixture of native and invasive species, and most have very low rates of native species regeneration.  How can we facilitate sustainable native biodiversity and maintain ecosystem goods and services, while minimizing management inputs? We suggest an approach similar to fantasy football, where ‘teams’ of species are picked to work together to form self-sustaining units. We present an approach for choice of species (‘players’) based on functional trait characteristics of native and non-invasive introduced species, and on functional diversity indices from existing lowland forests with varying degrees of domination by exotic species. We tested this approach by determining the functional characteristics of 29 candidate species across east Hawai‘i Island, and those of naturally-formed assemblages in the region.

Results/Conclusions

Sampling of functional traits across the study species showed native and non-native species separating into distinct groups based primarily on foliar carbon to nitrogen ratios, SLA and total leaf nitrogen content. Secondary subsets of species emerged, whose grouping was based on characteristics such as taxonomic status (e.g., palms independent of status as native or non-native), habitat preferences (e.g., species with high light requirements) and growth form (plant structure and total height). Together with data collected on functional diversity, we suggest that new hybrid communities can be experimentally assembled based on principles of complementarity and redundancy.