title: Specialization and rarity predict nonrandom loss of interactions from mutualist networks.
abstract: The loss of interactions from mutualistic networks could foreshadow both plant and animal species extinctions. Yet, the characteristics of interactions that predispose them to disruption are largely unknown. We analyzed 12 pollination webs from isolated hills ("sierras"), in Argentina, ranging from tens to thousands of hectares. We found evidence of nonrandom loss of interactions with decreasing sierra size. Low interaction frequency and high specialization between interacting partners contributed additively to increase the vulnerability of interactions to disruption. Interactions between generalists in the largest sierras were ubiquitous across sierras, but many of them lost their central structural role in the smallest sierras. Thus, particular configurations of interaction networks, along with unique ecological relations and evolutionary pathways, could be lost forever after habitat reduction.
authors.affiliation: Laboratorio Ecotono-Centro Regional Universitario Bariloche (CRUB), Universidad Nacional del Comahue, San Carlos de Bariloche, Río Negro, Argentina. maizen@comahue-conicet.gob.ar
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Aizen
authors.forename: Malena
authors.initials: M
authors.lastname: Sabatino
authors.forename: Jason M
authors.initials: JM
authors.lastname: Tylianakis
mesh_terms: D000818:Animals; D001118:Argentina; D044822:Biodiversity; D005075:Biological Evolution; D017753:Ecosystem; D020387:Food Chain; D007313:Insecta; D010944:Plants; D054817:Pollination; D011157:Population Dynamics; D013559:Symbiosis