Developing integrated ecosystem indices

• Proposes developing integrated indices of human dimensions and natural system indicators.
• These integrated indices employ a hierarchical, recursive relationship.
• The method allows assessment of the holistic ecosystem while maintaining detailed information.
• Consistent indices enable comparison of human dimensions and natural system conditions.

Enabling ecosystem-based management requires, among other things, reaching a scientifically based consensus with respect to the key characteristics of a sustainable ecosystem capable of supporting those levels of key ecosystem services desired by society. To determine and convey whether an ecosystem is in fact approaching this goal implies developing indicators that capture the status of both the natural and societal aspects of the system. That said, developing consistent and useful indicators for both societal and natural system aspects of the ecosystem requires both resolving disparate perspectives and inconsistent terminology between human dimensions and natural system scientists and keeping the number of indicators manageably few, without oversimplifying a highly complex ecosystem. To accomplish this we employed a “recursive relationship” approach that defined (and redefined) variables, indicators, and indices along a sliding hierarchy from measurable parameters to highly aggregated indices. To illustrate this approach it is applied herein to both a human dimensions index (recreational quality), and a natural sciences index (water column). This “recursive relationship” approach facilitated development of a parsimonious set of high-level indices that together constitute an ecosystem report card integrating natural system status and related societal dimensions from an ecosystem services perspective, while maintaining all of the information at lower levels necessary to inform specific management decisions.