The height, breadth and depth of physiological diversity

Speakers

Curtis Deutsch

Curtis Deutsch

Associate Professor (University of Washington, USA)

Talk title: Diversity of marine hypoxia traits: Implications for biodiversity and extinction

The role of climate in shaping species habitats is mediated by a variety of physiological and ecological traits.  Here we analyze three traits regulating aerobic habitat of marine animals: the physiological oxygen tolerance, its sensitivity to temperature, and the factor by which resting O2 demand is elevated by the energetic requirement for ecological activity. Across >70 diverse species, hypoxia vulnerability varies widely, and is shown to arise from coupled variations in O2 supply and demand.  Despite this physiological diversity, species from disparate ocean environments all currently encounter a lower limit of O2 supply to demand (Metabolic Index) whose distribution of values is indistinguishable from the active to resting energetic ratios of terrestrial animals.  These results extend and strengthen previous findings that the geographic range of marine species is limited in part by energetic requirements common to all life.


Enrico Rezende

Enrico Rezende

Assistant Professor (Pontifical Catholic University of Chile, Chile)

Talk title: Thermal performance across levels of biological complexity

Forecasting which lineages and ecosystems are vulnerable or resilient to ongoing global climate change remains a crucial challenge. The relationship between environmental temperature and performance among ectotherms, or thermal performance curve, is currently used as a baseline to examine the response of organisms under scenarios of global warming. Unfortunately, predictions ignore the confounding effects of increasing complexity as biological levels of organization increase: whereas measurements often focus on performance at the level of the organism, responses involve demographic processes other than survival that are expressed at the population level or higher. We developed an integrative analysis to study if thermal performance curves vary predictably across levels of biological complexity, and show that this is indeed the case. We discuss how this observation might impact their putative use as an indicator of the effect of global warming on organisms along geographic gradients.

Biography:

Assistant Professor at the Catholic University of Chile. Bachelor in Sciences from the University of Chile, PhD from University of California Riverside. Postdoctoral experience as a Ramón y Cajal and Young Talent Fellow, awarded for young researchers by the Spanish and Brazilian governments, respectively, and previous position as Senior Lecturer at the University of Roehampton, UK. Author of 70 ISI articles, currently Senior Editor for Functional Ecology.


Francisco Bozinovic

Francisco Bozinovic

Professor (Pontifical Catholic University of Chile, Chile)

Talk title: Thermal performance across levels of biological complexity

Forecasting which lineages and ecosystems are vulnerable or resilient to ongoing global climate change remains a crucial challenge. The relationship between environmental temperature and performance among ectotherms, or thermal performance curve, is currently used as a baseline to examine the response of organisms under scenarios of global warming. Unfortunately, predictions ignore the confounding effects of increasing complexity as biological levels of organization increase: whereas measurements often focus on performance at the level of the organism, responses involve demographic processes other than survival that are expressed at the population level or higher. We developed an integrative analysis to study if thermal performance curves vary predictably across levels of biological complexity, and show that this is indeed the case. We discuss how this observation might impact their putative use as an indicator of the effect of global warming on organisms along geographic gradients.

Biography:

Full Professor at the Catholic University of Chile. Bachelor and Ph.D. from the University of Chile; Post-Doctorate by Carnegie, USA. Researcher responsible in the Center of Applied Ecology and Sustainability and the International Laboratory of Global Change. Author of approximately 300 ISI articles and three books. Has directed 9 M.Sc and 21 Ph.D. thesis; he has also guided 17 post-docs. Visiting professor of national and international universities, editor and member of the editorial committees of ten mainstream journals. Belongs to the Chilean Academy of Sciences, received fellowships  from  Andes Foundation, Carnegie Institution and J.S. Guggenheim; Scopus-Elsevier award, among others.


Jennifer Sunday

Jennifer Sunday

Associate Professor (McGill University, Canada)

Talk title: Environmental variability across marine and terrestrial gradients

Connecting physiological responses at the organism level to species-level patterns of abundance and distribution is a key challenge in ecology. Here I explore the role of variability in temperature and pH in improving linkages between physiological data and species distributions and projecting responses to environmental change.

Biography:

Jennifer Sunday’s research is focused on understanding the ecological factors that determine species’ biogeographical ranges and their responses to environmental change. She uses analyses of biogeography through time, comparative traits-based analyses, and laboratory experimental approaches to better understand ecological and evolutionary responses to environmental change.


John Spicer

John Spicer

Professor of Marine Zoology (University of Plymouth, UK)

Talk title: There may be giants – but why? Testing the oxygen hypothesis of gigantism with amphipod crustaceans

Adaptation to the Polar oceans has led to the evolution of unique physiological traits to cope with life in the constant cold, where metabolic rates are low. The paradigm states that body size of polar marine ectotherms can be bigger than in warmer or lower oxygen environments. The resultant expectations are that: 1) large species will have poor physiological capacity under low oxygen and 2) larger species and individuals will be more susceptible to oxygen limitation under warming. To test these hypotheses, the oxygen consumption of 3 species of Antarctic amphipod, collected at Rothera research station (67°S), was investigated in closed cell respirometers.Paracerodocus miersi (30-40mm),Prostabbingia brevicornis (20mm) and P. gracilis (15mm) all live in hollows underneath rocks. The swimming speeds of two of these species, P. miersi and P. brevicornis, were tested at temperatures ranging between 0 and 9°C.

P. miersiis an oxyconformer; its oxygen consumption fell with ambient oxygen concentration and it did not alter its ventilation rate. This species also maintained the same speed of locomotion between 0 and 9°C.P. brevicornismaintained a constant oxygen consumption from 100 to 40% of air saturation with increased ventilation rate, possibly assisted by its extra-branchial surfaces. The swimming speed ofP. brevicornisincreased up to 3°C but dropped at higher temperatures.P. graciliswas intermediate to the two other amphipods.

The differences between these species suggest that mixed strategies have evolved in response to oxygen availability in polar waters.


Scott Bennett

Scott Bennett

Marie Curie Research Fellow (Mediterranean Institute of Advanced Studies (IMEDEA), Spain)

Talk title: Population vulnerability to warming across latitudinal gradients

Here we estimate warming vulnerability for coastal marine communities across latitudinal gradients, capturing the full spectrum of local physiological adaptability that may exist among species within a community. We identify several global hot-spots and safe-spots of climate change vulnerability for marine communities and highlight many coastal areas where populations with locally-adapted and conserved thermal niches display stark differences in climate change vulnerability. These findings highlight important variation in warming vulnerability within and among biological communities across latitudinal gradients, enhancing our capacity to anticipate climate change impacts and identify areas of management priority from local to global scales.

Biography:

Scott Bennett is broadly interested in understanding the ecological and evolutionary processes that shape the structure, function and resilience of coastal marine ecosystems. His work has an emphasis on population, community and climate change ecology and principally applies comparative experimental approaches to test the spatial and temporal context of processes across broad environmental gradients.


Simon Morley

Simon Morley

Ecophysiologist (British Antarctic Survey, UK)

Talk title: There may be giants – but why? Testing the oxygen hypothesis of gigantism with amphipod crustaceans

Adaptation to the Polar oceans has led to the evolution of unique physiological traits to cope with life in the constant cold, where metabolic rates are low. The paradigm states that body size of polar marine ectotherms can be bigger than in warmer or lower oxygen environments. The resultant expectations are that: 1) large species will have poor physiological capacity under low oxygen and 2) larger species and individuals will be more susceptible to oxygen limitation under warming. To test these hypotheses, the oxygen consumption of 3 species of Antarctic amphipod, collected at Rothera research station (67°S), was investigated in closed cell respirometers.Paracerodocus miersi (30-40mm),Prostabbingia brevicornis (20mm) and P. gracilis (15mm) all live in hollows underneath rocks. The swimming speeds of two of these species, P. miersi and P. brevicornis, were tested at temperatures ranging between 0 and 9°C.

P. miersiis an oxyconformer; its oxygen consumption fell with ambient oxygen concentration and it did not alter its ventilation rate. This species also maintained the same speed of locomotion between 0 and 9°C.P. brevicornismaintained a constant oxygen consumption from 100 to 40% of air saturation with increased ventilation rate, possibly assisted by its extra-branchial surfaces. The swimming speed ofP. brevicornisincreased up to 3°C but dropped at higher temperatures.P. graciliswas intermediate to the two other amphipods.

The differences between these species suggest that mixed strategies have evolved in response to oxygen availability in polar waters.

Biography:

Simon Morley is a marine biologist working in the Polar Regions whose research focuses on the mechanisms underlying physiological tolerance and therefore community structure across environmental gradients. Our research ranges across temporal, spatial and biological scales to identify the key factors that are likely to determine community resilience. The aim is to provide better tools for managing marine ecosystems.


Steven Chown

Steven Chown

Professor (Monash University, Australia)

Talk title: Thermal foraging traits as mediators of ant abundance and occupancy variation

In this work, we test key hypotheses about the way in which thermal traits mediate interspecific variation in abundance and occupancy across broad spatial scales, and their implications for global change impact forecasts. We use a decade-long, bi-annual survey of abundance variation in 53 ant species from 37 sites, spanning major climatic gradients in Southern Africa. We show that broad relationships do exist between microclimate, thermal tolerance limits and foraging limits. However, interspecific variation in the range of temperatures over which ants can forage and, in consequence, the time available for foraging in given settings (which includes the influence of interspecific interactions), are much better predictors of variation in abundance and occupancy.

Biography:

Steven L. Chown holds a Professorship in Biological Sciences at Monash University, Australia. A key part of his research concerns the biological impacts of the major global change drivers, and he is jointly responsible for the development of macrophysiology. He has published widely, including many scientific papers and several scientific and popular books. Steven is the inaugural recipient of the Tinker-Muse Prize for science and policy in Antarctica. He has also received the SCAR Medal for Excellence in Antarctic Research, the South African Antarctic Gold Medal, and the Zoological Society of Southern Africa Gold Medal.