Engineering role models: do non-human species have the answers?

A shift from traditional engineering approaches to ecologically-based techniques will require changing societal values regarding ‘how and what’ is defined as engineering and design. Non-human species offer many ecological engineering examples that are often beneficial to ecosystem function and other biota. For example, organisms known as ‘ecosystem engineers’ build, modify, and destroy habitat in their quest for food and survival. Similarly, ‘keystone species’ have greater impacts on community or ecosystem function than would be predicted from their abundance. The capacity of these types of organisms to affect ecosystems is great. They exert controlling influences over ecosystems and communities by altering resource allocation, creating habitats and modifying relative competitive advantages. Species’ effects in ecosystems, although context-dependent, can be evaluated as ‘beneficial’ or ‘detrimental’. The evaluation depends on whether effects on other species or ecosystem function are more or less desirable from a given perspective. Organisms with beneficial impacts facilitate the presence of other species, employ efficient nutrient cycling, and are sometimes characterized by specific mutualisms. In contrast, many cases of detrimental engineering are found from introduced (i.e., exotic) species and are characterized by a loss of species richness, a lack of nutrient retention and the degradation of ecosystem integrity. Species’ impacts on ecosystems and community traits have been quantified in ecological studies and can be used similarly to understand, design and model human engineering structures and impacts on the landscape. Emulation of species with beneficial impacts on ecosystems can provide powerful guidance to the goals of ecological engineering. Using role model organisms that have desirable effects on species diversity and ecosystem function will be important in developing alternatives to traditional engineering practices. © 2003 Elsevier B.V. All rights reserved.