Measuring ecological complexity

Complexity is an elusive term in ecology that is often used in different ways to describe the state of an ecosystem. Ecological complexity has been linked to concepts such as ecological integrity, diversity and resilience and has been put forth as a candidate ecological orientor. In this article, the concept of complexity as a system attribute is presented and candidate measures of ecological complexity are reviewed. The measures are distinguished by their ability to characterize the spatial, temporal, structural or spatiotemporal signatures of an ecosystem. Many of these measures have been adapted from disciplines such as physics and information theory that have a long history of quantifying complexity, however more work needs to be done to develop techniques adapted to ecological data. It is argued that if appropriate measures are developed and validated for ecosystems, ecological complexity could become a key ecological indicator.