Thursday, August 9, 2007: 8:00 AM-11:30 AM
A3&6, San Jose McEnery Convention Center
SYMP 18 - Yin and yang: The combined influences of positive and negative interactions in ecological communities
Ecological interactions can be positive, negative, or neutral, though to-date negative effects (competition, predation, parasitism, abiotic stress) have received the lionís share of attention. There has been significant progress in understanding how positive interactions (mutualism, facilitation) influence community structure and ecosystem processes. Despite this newfound attention, less progress has been made in integrating the relative roles of positive and negative interactions into a coherent picture of ecological and evolutionary processes. Interactions commonly classified as mutualism or facilitation are increasingly recognized to be dynamic and context dependent. Mutualism is now sometimes thought of as a reciprocal parasitism that alternates between positive and negative interactions. Consequently, a pairwise interaction that is beneficial to a species in one context can be neutral or negative in other another. While case studies of context-dependent mutualisms have accumulated, there is still little synthesis to predict when and where potential mutualisms or facilitations are likely to emerge. The goal of this symposium will be to form a bridge between the two research areas outlined above. Two principal questions will be addressed. First, can we understand the conditions where mutualism and facilitation develops between pairs of species? Are there attributes of certain communities or environments that foster the development of mutualisms between component species? Second, does an understanding of context-dependency in pairwise interactions allow us to understand how positive interactions work to structure entire communities?
Organizer:Kailen A. Mooney, Cornell University
Co-organizer:John D. Parker, Cornell University
Moderator:John D. Parker, Cornell University
8:00 AMIntroductory remarks: Positive vs. negative interactions in the function of ecological communities
John D. Parker, Cornell University
8:10 AMTwo sides of the same coin: Conditional outcomes and conflicting selection pressures in plant-pollinator-herbivore interactions
Lynn Adler, University of Massachusetts
8:30 AMTheoretical perspective: Evolutionary dynamics of mutualisms in a variable environment
Claire de Mazancourt, McGill University
8:50 AMCooperation and exploitation: Exploring how parasites shape the success and stability of mutualisms
Cameron R. Currie, University of Wisconsin, Ainslie E.F. Little, University of Wisconsin
9:10 AMBreak
9:20 AMCommunity impacts of context dependence in ant-aphid mutualisms
Kailen A. Mooney, University of California at Irvine
9:40 AMMutualisms as keystone interactions and extended phenotypes
Micky D. Eubanks, Auburn University
10:00 AMMovement of arbuscular mycorrhizae along the mutualism-parasitism continuum
James D. Bever, Indiana University
10:20 AMSmall mutualists with big impacts: Community-level consequences of pairwise mutualisms between fungal endophytes and grasses
Jennifer Rudgers, Rice University
10:40 AMSimultaneous positive and negative plant-microbe interactions in plant communities / Symposium summary and synthesis
John Klironomos, University of Guelph
11:10 AMDiscussion

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See more of The ESA/SER Joint Meeting (August 5 -- August 10, 2007)