99th ESA Annual Meeting (August 10 -- 15, 2014)

SYMP 16

Measuring Biotic Resistance from Mountains to Oceans

The observation that some ecosystems are more resistant to biological invasions than others dates back at least as far as Darwin’s observations, but was most famously articulated by Elton’s famous observational comparisons in invasibility between temperate and tropical, island and mainland, and agriculture versus natural systems. Although empirical work on biotic resistance (BR) has been expanding, a broad synthetic understanding of the conditions under which biotic resistance might be weak or strong has been slow in coming. Part of the reason for this concerns definitions; at what point does biotic resistance become meaningful? Are we most concerned about whether biotic resistance influences establishment or the abundance of established populations? Can we move beyond measures of impacts of BR on performance and more towards effects on populations? Are there predictable differences among systems in invasibility or in the impacts of competitive versus consumptive processes on imposing resistance? Recent meta-analyses have suggested intriguing patterns, but broad comparisons are plagued by in methodologies, definitions, and approaches. The primary goal of this symposium is to develop a more synthetic and predictive understanding of biotic resistance. Participants that have worked in diverse systems (marine, fresh water and terrestrial) will use their own data as a starting point and not an end point. Using their own data as motivation, participants will be required to discuss how best to: 1) operationally define BR, 2) measure standardized impacts of BR, and 3) measure attributes of species or systems that could best be used to predict the strength of BR. While there is great interest in BR, much of the work in this area has been idiosyncratic; the time is ripe for a more synthetic approach to this problem. Recent meta-analyses have suggested some intriguing patterns, but more efforts devoted to enhancing prediction of the systems and organisms that might be most prone to BR are needed. We anticipate that the results of this symposium will lead to reviews that will capture the results of the symposium as well as follow up work with additional authors. We also expect that the presenters will collaborate on an extensive review paper that will present the results of the symposium in a synthetic light. We may also be able to target a review format like Trends in Ecology and Evolution or Annual Review of Ecology, Evolution and Systematics.