Anthropogenic areas as incidental substitutes for original habitat.
One speaks of ecological substitutes when an introduced species performs, to some extent, the ecosystem function of an extirpated native species. We suggest that a similar case exists for habitats. Species evolve within ecosystems, but habitats can be destroyed or modified by natural and human-made causes. Sometimes habitat alteration forces animals to move to or remain in a suboptimal habitat type. In that case, the habitat is considered a refuge, and the species is called a refugee. Typically refugee species have lower population growth rates than in their original habitats. Human action may lead to the unintended generation of artificial or semiartificial habitat types that functionally resemble the essential features of the original habitat and thus allow a population growth rate of the same magnitude or higher than in the original habitat. We call such areas substitution habitats and define them as human-made habitats within the focal species range that by chance are partial substitutes for the species' original habitat. We call species occupying a substitution habitat adopted species. These are 2 new terms in conservation biology. Examples of substitution habitats are dams for European otters, wheat and rice fields for many steppeland and aquatic birds, and urban areas for storks, falcons, and swifts. Although substitution habitats can bring about increased resilience against the agents of global change, the conservation of original habitat types remains a conservation priority.
Evolutionary Biology Group, Facultad de Ciencias, Universidade da Coruña, Campus da Zapateira s/n, 15071, A Coruña, Spain. a.abrain@udc.es.|Population Ecology Group, Mediterranean Institute of Advanced Studies (CSIC-UIB), C/Miquel Marquès 21, 07190, Esporles, Mallorca, Spain. a.abrain@udc.es.
Alejandro
A
Martínez-Abraín
Servicio de Vida Silvestre, Consellería de Infraestructuras, Territorio y Medio Ambiente, Generalitat Valenciana, C/ Castán Tobeñas, 77, 46018, Valencia, Spain.
Juan
J
Jiménez
D000818:Animals; D001717:Birds; D003247:Conservation of Natural Resources; D017753:Ecosystem; D006801:Humans; D010041:Otters
adopted species; conceptos nuevos; conservación; conservation; equivalencia funcional; especies adoptadas; functional equivalence; human-modified systems; hábitats sustitutos; new concepts; resilience; resiliencia; sistemas modificados por humanos; substitution habitats