The world needs biogeographers
A recent meeting of the International Biogeographical Society discusses the past, present and future impacts of climate on biodiversity.
"The world needs biogeographers" led the opening address by society President Dov Sax to the assembled crowd at the Climate Change Biogeography meeting in Évora, Portugal, last week. Biogeography as a scientific discipline has a long history, running back as least as far as the work of Alexander von Humboldt, whose 250th birthday the society will be celebrating next year. Acknowledging that a distinguished history also comes with it the danger of being perceived as "stuffy", Sax argues that, in the face of rapid climatic change, never has there been a more urgent time for scientists to study the impacts of this change on the natural world.
With this historical context in mind, the meeting started by looking backwards. To understand how communities in the future will respond to climatic change we can look to the past, using the paleoecological record. Kate Lyons' (University of Nebraska Lincoln) opening plenary on the influence of climate and biodiversity loss on community structure and function outlined her work disentangling the relative roles of climate and humans on the fossil record and co-occurrence structure of North American mammals. Past climatic change has coincided with increases in range size, and community homogenisation, with levels of homogenisation seen in the Pleistocene greater than that predicted to occur under future climatic scenarios [read more in Lyons et al 2016 Nature].
In a similar vein, Felisa Smith (University of New Mexico) concluded the opening plenary session by discussing the impacts of climate at the individual level, with evidence of past climatic influences on mammalian body size through the Cenozoic. Although massive body size changes occurred after the K/Pg mass extinction opened up ecological space for mammals, it seems that no consistent pattern in body size change with climate has happened over the last 65 million years --except when humans appeared on the scene [read more in Smith et al 2010 Science]
Flying the flag for non-biologists, climate scientist Alan Haywood (University of Leeds) cautioned that collaboration and interdisciplinarity should continue to be strengthened in the field of climate change ecology, outlining how the use of climatic models in biogeographic analysis is perhaps "not optimal" at present. Catalina Pimiento's (Museum für Naturkunde) talk on the impacts of past sea level change on marine megafauna was also one of only a handful of talks that outlined impacts of climate on non-terrestrial environments [read more in Pimiento et al 2017 Nature Ecology and Evolution].
Moving from the past to the present, José Alexandre Felizola Diniz Filho (Universidade Federal de Goias) highlighted new approaches to understanding the feedback between ecology and evolution as species shift their ranges under climate. Combining quantitative genetics and comparative analyses, his work cautioned that not adequately accounting for plasticity and adaptation to changing climates could lead to overestimating future extinction rates. Conclusions like this will also clearly require a cautious approach in the way they are reported, in case they give the mistaken impression that taking action over climatic change is less urgent than it appears.
Of course, species are not just shifting their latitudinal ranges, they are also moving upwards. Mountains as testbeds for future warming scenarios was a major focus here too, as they provide a natural environmental gradient in which to explore how species respond to temperature change. Erin Cameron (University of Helsinki) raised awareness of just how little information there is in the literature about the spread of non-native terrestrial invertebrates in mountains (answer: not enough for a meta-analysis), although the state of knowledge appears healthier in plants: describing the results of a major global synthesis, Sylvia Haider (Martin-Luther-University Halle-Wittenberg) outlined how the spread of lowland flora upslope appears to be the principle driver of plant invasions in mountains across the world, more so than by any particular groups of invasive taxa. [Read more in McDougall et al 2010 Diversity and Distributions].
The city of Évora and its university was a beautiful venue in which to welcome this diverse, international crowd of biogeographers, and the society and meeting organisers should be congratulated for a stimulating few days of science. Special mention should also be made of the exemplary balance of plenary speakers from across continents, career stages, and gender. Biogeography may be an old science, but there's little sign of any stuffiness here.