2019 article
Ecology in the Sixth Mass Extinction: Detecting and Understanding Rare Biotic Interactions
Youngsteadt, E., Lopez-Uribe, M. M., & Sorenson, C. E. (2019, May). ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA, Vol. 112, pp. 119–121.
The Earth is experiencing a wave of anthropogenic biodiversity loss, such that current rates of extinction are 100–1,000 times the background rate observed between prior mass extinctions in the fossil record (Barnosky et al. 2011, Pimm et al. 2014). These losses place Earth’s biota in the early stages of an extinction event comparable to those precipitated only five times before in the past 540 million years (Barnosky et al. 2011, Ceballos et al. 2015). Among plants—the foundation of terrestrial food webs—an estimated 20% of all species are currently threatened with extinction (Brummitt et al. 2015). Among invertebrates, conservation status has been reviewed for only about 1% of described species, and of those, some 40% are threatened (Dirzo et al. 2014). Regional surveys regularly detect striking losses in insect biomass and population size over recent decades (e.g., Fox 2013, Hallmann et al. 2017, Lister and Garcia 2018). Loss of species richness, population size, and biomass are striking, but they do not capture the full impact of biotic change. Each species participates in a web of interactions, such as predation, parasitism, and mutualism, that underpin ecosystem functions (Tylianakis et al. 2008). These interactions are expected to disappear before the species themselves (McConkey and Drake 2006, Valiente-Banuet et al. 2015), precipitating changes in ecosystem function and extinction of other species that depend on the interactions (Säterberg et al. 2013, Risch et al. 2018). In this context, the study of rare biotic interactions is becoming more widespread and more urgent; however, challenges abound in detecting such interactions and interpreting their ecological relevance. These challenges were the focus of a Plant-Insect Ecosystems Section Symposium convened at the 2017 annual meeting of the Entomological Society of America in Denver, CO. Among the symposium’s 16 presenters, 6 contributed papers to this collection, providing a cross section of the dimensions of rarity with which ecologists must grapple.