Positive and Negative Effects of Organisms as Physical Ecosystem Engineers

Abstract

Abstract. Physical ecosystem engineers are organisms that directly or indirectly control the availability of resources to other organisms by causing physical state changes in biotic or abiotic materials. Physical ecosystem engineering by organisms is the physical modification, maintenance, or creation of habitats. Ecological effects of engineers on many other species occur in virtually all ecosystems because the physical state changes directly create nonfood resources such as living space, directly control abiotic resources, and indirectly modulate abiotic forces that, in turn, affect resource use by other organisms. Trophic interactions and resource competition do not constitute engineering. Engineering can have significant or trivial effects on other species, may involve the physical structure of an organism (like a tree) or structures made by an organism (like a beaver dam), and can, but does not invariably, have feedback effects on the engineer. We argue that engineering has both negative and positive effects on species richness and abundances at small scales, but the net effects are probably positive at larger scales encompassing engineered and nonengineered environments in ecological and evolutionary space and time. Models of the population dynamics of engineers suggest that the engineer/habitat equilibrium is often, but not always, locally stable and may show long-term cycles, with potential ramifications for community and ecosystem stability. As yet, data adequate to parameterize such a model do not exist for any engineer species. Because engineers control flows of energy and materials but do not have to participate in these flows, energy, mass, and stoichiometry do not appear to be useful in predicting which engineers will have big effects. Empirical observations suggest some potential generalizations about which species will be important engineers in which ecosystems. We point out some of the obvious, and not so obvious, ways in which engineering and trophic relations interact, and we call for greater research on physical ecosystem engineers, their impacts, and their interface with trophic relations.

Alien species in a warmer world: risks and opportunities

“…These changes pose complex challenges for the management of biodiversity as well as of wild and cultivated resources and could include implications for ecosystem functioning, especially with the addition or loss of ecosystem engineers [96]. Hence, management practices with regard to the occurrence of 'new' species will require comprehensive evaluation of changing habitat conditions and will depend on the individual case.…”

Zonación vertical del macrobentos de sustratos sólidos del estuario del río Massangana, Bahía de Suape, Pernambuco, Brasil

“…2009 y Tanaidacea. Según Jones et al (1997), aunque la presencia de estas algas en mangles aumente la cantidad de nichos, ella provoca la disminución de la competición de forma indirecta por espacio. Los patrones de distribución vertical de la comunidad faunística epibionte, por otro lado, son atribuidos a disturbios antropogénicos, disponibilidad de alimentos, patrones de reclutamiento larval, depredación, competencia y regímenes de mareas (Sutherland 1980, Perry 1988, Ellison & Farnsworth 1992.…”

Benthic assemblages associated with native and non-native oysters are similar

“…Some invasive species that are considered ecosystem engineers (sensu Jones et al, 1997), however may provide structure and shelter for other species, which can occasionally lead to increased local species diversity (Crooks, 2002;Rodriguez, 2006). The zebra mussel Dreissena polymorpha, for example, an invasive ecosystem engineer in fresh water and estuarine habitat increases the diversity of other associated benthic consumers and primary producers, albeit by altering plankton communities (Higgins and Vander Zanden, 2015).…”