Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Received 30 January 2002 Accepted 26 March 2002

Summary: Received 30 January 2002
Accepted 26 March 2002
Published online 11 June 2002
Bene ts and costs of mutualism: demographic
consequences in a pollinating seed­consumer
J. Nathaniel Holland
Department of Biology, University of Miami, Coral Gables, FL 33124, USA ( jholland@email.arizona.edu)
Interspeci c interactions can affect population dynamics and the evolution of species traits by altering
demographic rates such as reproduction and survival. The in uence of mutualism on population processes
is thought to depend on both the bene ts and costs of the interaction. However, few studies have explicitly
quanti ed both bene ts and costs in terms of demographic rates; furthermore there has been little con-
sideration as to how bene ts and costs depend on the demographic effects of factors extrinsic to the
interaction. I studied how bene ts (pollination) and costs (larval fruit consumption) of pollinating seed-
consumers (senita moths) affect the reproduction of senita cacti and how these effects may rely on extrinsic
water limitation for reproduction. Fruit initiation was not limited by moth pollination, but survival of
initiated fruit increased when moth eggs were removed from owers. Watered cacti produced more owers
and initiated more fruit from hand-pollinated owers than did unwatered cacti, but fruit initiation
remained low despite excess pollen. Even though water, pollination and larvae each affected a component
of cactus reproduction, when all of these factors were included in a factorial experiment, pollination and


Source: Azevedo, Ricardo - Department of Biology and Biochemistry, University of Houston
Holland, J. Nathaniel - Department of Ecology and Evolutionary Biology, Rice University


Collections: Biology and Medicine; Environmental Sciences and Ecology