Degree distribution in plant-animal mutualistic networks: forbidden links or random interactions?

VÁZQUEZ DP

OIKOS

Año: 2005 vol. 108 p. 421 - 426

0030-1299

Recent studies show that ecological interaction networks departfrom the ‘‘scale-free’’ topologies observed in many other realworld networks. Such a departure has been hypothesized to resultfrom non-matching biological attributes of species, such asphenology or morphology, that prevent the occurrence of certaininteractions (‘‘forbidden links’’). Here I compare the topology of17 plant
/animal mutualistic networks with that predicted by asimple null model that assumes that a species’ degree (number ofinterspecific interactions) is a function of its frequency ofinteraction. The topology predicted by this null model isstrikingly close to that observed in the real networks. Thus, thisnull model provides a simple alternative interpretation of patternsobserved in ecological interaction networks that does not requirethe existence of non-matching species traits.