scholarly journals An empirical test of the temperature dependence of carrying capacity

2017 ◽  
Author(s):  
Joey R. Bernhardt ◽  
Jennifer M. Sunday ◽  
Mary I. O’Connor
Keyword(s):  
Global Change ◽  
Temperature Dependence ◽  
Carrying Capacity ◽  
Empirical Test ◽  
Population Abundance ◽  
Metabolic Rates ◽  
Metabolic Scaling ◽  
Theoretical Predictions ◽  
Effects Of Temperature ◽  
Metabolic Performance

AbstractPredicting population persistence and dynamics in the context of global change is a major challenge for ecology. A widely held prediction is that population abundance at carrying capacity decreases with warming, assuming no change in resource supply, due to increased individual resource demands associated with higher metabolic rates. However, this prediction, which is based on metabolic scaling theory (MST), has not been tested empirically. Here we experimentally tested whether effects of temperature on short-term metabolic performance (rates of photosynthesis and respiration) translate directly to effects of temperature on population rates in a phytoplankton species. We found that effects of temperature on organismal metabolic rates matched theoretical predictions, and that the temperature dependence of individual metabolic performance translated to population abundance. Population abundance at carrying capacity, K, decreased with temperature less than expected based on the temperature dependence of photosynthesis. Concurrent with declines in abundance, we observed a linear decline in cell size of approximately 2.3% °C−1, which is consistent with broadly observed patterns in unicellular organisms, known as the temperature-size rule. When theoretical predictions include higher densities allowed by shifts toward smaller individual size, observed declines in K were quantitatively consistent with theoretical predictions. Our results indicate that outcomes of population dynamics across a range of temperatures reflect organismal responses to temperature via metabolic scaling, providing a general basis for forecasting population responses to global change.

scholarly journals Brain size varies with temperature in vertebrates

2014 ◽  
Author(s):  
James F Gillooly
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Dependence ◽  
Aerobic Capacity ◽  
Brain Size ◽  
Metabolic Rates ◽  
Temperature Dependent ◽  
Spatial And Temporal Scales ◽  
Effects Of Temperature

The tremendous variation in brain size among vertebrates has long been thought to be related to differences in species’ metabolic rates. Species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here I explore the effects of temperature on brain size among diverse vertebrates (fishes,amphibians, reptiles, birds and mammals). I find that, after controlling for body size,brain size increases exponentially with temperature in much the same way asmetabolic rate. These results suggest that temperature-dependent changes in aerobic capacity, which have long been known to affect physical performance, similarly affect brain size. The observed temperature-dependence of brain size may explain observed gradients in brain size among both ectotherms and endotherms across broad spatial and temporal scales.

scholarly journals Brain size varies with temperature in vertebrates

2014 ◽  
Author(s):  
James F Gillooly
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Dependence ◽  
Aerobic Capacity ◽  
Brain Size ◽  
Metabolic Rates ◽  
Temperature Dependent ◽  
Spatial And Temporal Scales ◽  
Effects Of Temperature

The tremendous variation in brain size among vertebrates has long been thought to be related to differences in species’ metabolic rates. Species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here I explore the effects of temperature on brain size among diverse vertebrates (fishes,amphibians, reptiles, birds and mammals). I find that, after controlling for body size,brain size increases exponentially with temperature in much the same way asmetabolic rate. These results suggest that temperature-dependent changes in aerobic capacity, which have long been known to affect physical performance, similarly affect brain size. The observed temperature-dependence of brain size may explain observed gradients in brain size among both ectotherms and endotherms across broad spatial and temporal scales.

scholarly journals Hotter is Smarter: The temperature-dependence of brain size in vertebrates

2013 ◽  
Author(s):  
James JF Gillooly
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Dependence ◽  
Brain Tissue ◽  
Brain Size ◽  
Metabolic Rates ◽  
Temperature Dependent ◽  
Spatial And Temporal Scales ◽  
Effects Of Temperature

The tremendous variation in brain size among vertebrates has long been thought to be related to differences in species’ metabolic rates. Species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here I explore the effects of temperature on brain size among diverse vertebrates (fishes,amphibians, reptiles, birds and mammals). I find that, after controlling for body size,brain size increases exponentially with temperature in much the same way asmetabolic rate. These results suggest that temperature-dependent changes inaerobic capacity, which have long been known to affect physical performance, similarly affect brain size. The observed temperature-dependence of brain size may explain observed gradients in brain size among both ectotherms and endotherms across broad spatial and temporal scales.

scholarly journals Oxygen limitation may affect the temperature and size dependence of metabolism in aquatic ectotherms

2020 ◽  
Vol 117 (50) ◽  
pp. 31963-31968
Author(s):  
Juan G. Rubalcaba ◽  
Wilco C. E. P. Verberk ◽  
A. Jan Hendriks ◽  
Bart Saris ◽  
H. Arthur Woods
Keyword(s):  
Body Size ◽  
Aquatic Organisms ◽  
Oxygen Limitation ◽  
Oxygen Availability ◽  
Ecological Niches ◽  
Metabolic Rates ◽  
Aerobic Scope ◽  
Metabolic Theory ◽  
Metabolic Scaling ◽  
Effects Of Temperature

Both oxygen and temperature are fundamental factors determining metabolic performance, fitness, ecological niches, and responses of many aquatic organisms to climate change. Despite the importance of physical and physiological constraints on oxygen supply affecting aerobic metabolism of aquatic ectotherms, ecological theories such as the metabolic theory of ecology have focused on the effects of temperature rather than oxygen. This gap currently impedes mechanistic models from accurately predicting metabolic rates (i.e., oxygen consumption rates) of aquatic organisms and restricts predictions to resting metabolism, which is less affected by oxygen limitation. Here, we expand on models of metabolic scaling by accounting for the role of oxygen availability and temperature on both resting and active metabolic rates. Our model predicts that oxygen limitation is more likely to constrain metabolism in larger, warmer, and active fish. Consequently, active metabolic rates are less responsive to temperature than are resting metabolic rates, and metabolism scales to body size with a smaller exponent whenever temperatures or activity levels are higher. Results from a metaanalysis of fish metabolic rates are consistent with our model predictions. The observed interactive effects of temperature, oxygen availability, and body size predict that global warming will limit the aerobic scope of aquatic ectotherms and may place a greater metabolic burden on larger individuals, impairing their physiological performance in the future. Our model reconciles the metabolic theory with empirical observations of oxygen limitation and provides a formal, quantitative framework for predicting both resting and active metabolic rate and hence aerobic scope of aquatic ectotherms.

scholarly journals Temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean

2014 ◽  
Vol 11 (16) ◽  
pp. 4529-4540 ◽  
Author(s):  
L. S. García-Corral ◽  
E. Barber ◽  
A. Regaudie-de-Gioux ◽  
S. Sal ◽  
J. M. Holding ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Temperature Dependence ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Gross Primary Production ◽  
Activation Energies ◽  
Community Respiration ◽  
Metabolic Rates ◽  
Net Community Production ◽  
Different Seasons

Abstract. The temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean was assessed on the basis of measurements of gross primary production (GPP), community respiration (CR) and net community production (NCP), as well as experimental assessments of the response of CR to temperature manipulations. Metabolic rates were measured at 68 stations along three consecutive longitudinal transects completed during the Malaspina 2010 Expedition, in three different seasons. Temperature gradients were observed in depth and at basin and seasonal scale. The results showed seasonal variability in the metabolic rates, the highest rates being observed during the spring transect. The overall mean integrated GPP / CR ratio was 1.39 ± 0.27 decreasing from winter to summer, and the NCP for the subtropical North Atlantic Ocean during the cruises exhibits net autotrophy (NCP > 0) in about two-thirds (66%) of the total sampled communities. Also, we reported the activation energies describing the temperature dependence of planktonic community metabolism, which was generally higher for CR than for GPP in the subtropical North Atlantic Ocean, as the metabolic theory of ecology predicts. Furthermore, we made a comparison of activation energies describing the responses to in situ temperature in the field (EaCR = 1.64 ± 0.36 eV) and those derived experimentally by temperature manipulations (EaCR = 1.45 ± 0.6 eV), which showed great consistency.

Bird Metabolism During Flight: Evaluation of a Theory

1973 ◽  
Vol 58 (3) ◽  
pp. 689-709 ◽  
Author(s):  
VANCE A. TUCKER
Keyword(s):  
Reynolds Number ◽  
Absolute Error ◽  
Metabolic Rates ◽  
Avian Flight ◽  
Theoretical Predictions ◽  
Reynolds Number Effects ◽  
Plate Area ◽  
Laughing Gulls ◽  
Modified Theory ◽  
Approximate Equations

1. Pennycuick's (1969) theory for the energetic requirements of avian flight predicts the metabolic rates of budgerigars and laughing gulls flying level at intermediate speeds in a wind tunnel with an accuracy of 10% or better. However, its predictions appear to be low for most birds with masses less than 0·1 kg and high for most birds with masses greater than 0·5 kg. 2. Four modifications are made to Pennycuick's theory: (1) a different computation of induced power; (2) a different estimate of equivalent flat plate area that includes Reynolds number effects, and is based on additional measurements; (3) a different estimate of profile power that includes Reynolds number effects; and (4) the addition of power terms for respiration and circulation. These modifications improve the agreement between the theoretical predictions and existing measurements for flying birds and bats. 3. The metabolic rates of birds and bats in level flight at various speeds can be estimated by the modified theory if body mass alone is measured. Improved estimates can be made if wing span is measured as well. In the latter case the theory predicts measured values with a mean absolute error of 8·3%. 4. The results of the modified theory are presented by approximate equations that can be solved quickly for metabolic rate and flight speed with a slide rule.

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