-
Allometry of thermal variables in mammals: consequences of body size and phylogeny
-
A large number of analyses have examined how basal metabolic rate (BMR) is affected by body mass in mammals. By contrast, the critical ambient temperatures that define the thermo-neutral zone (TNZ), in which BMR is measured, have received much less attention. We provide the first phylogenetic analyses on scaling of lower and upper critical temperatures and the breadth of the TNZ in 204 mammal species from diverse orders. The phylogenetic signal of thermal variables was strong for all variables analysed. Most allometric relationships between thermal variables and body mass were significant and regressions using phylogenetic analyses fitted the data better than conventional regressions. Allometric exponents for all mammals were 0.19 for the lower critical temperature (expressed as body temperature - lower critical temperature), −0.027 for the upper critical temperature, and 0.17 for the breadth of TNZ. The small exponents for the breadth of the TNZ compared to the large exponents for BMR suggest that BMR per se affects the influence of body mass on TNZ only marginally. However, the breadth of the TNZ is also related to the apparent thermal conductance and it is therefore possible that BMR at different body masses is a function of both the heat exchange in the TNZ and that encountered below and above the TNZ to permit effective homeothermic thermoregulation.
Keywords: allometry,lower critical temperature,mammals,marsupials,thermal neutral zone,upper critical temperature.
Located in
Resources
/
Climate Science Documents
-
Carbon Dynamics of the Forest Sector
-
Main points: The basic ecosystem science behind carbon dynamics in forests is relatively straightforward (really!).This science doesn’t seem to be applied very routinely in the policy arena. This mismatch is undermining the potential of the forest sector in helping to mitigate greenhouse gases in the atmosphere
Located in
Resources
/
Climate Science Documents
-
USGS-NOAA: Climate Change Impacts to U.S. Coasts Threaten Public Health, Safety and Economy
-
According to a new technical report, the effects of climate change will continue to threaten the health and vitality of U.S. coastal communities' social, economic and natural systems.
Located in
News & Events
-
Wetlands clean water, provide homes for wildlife across the nation
-
Wetlands play a crucial role in the world’s ecosystem by protecting and improving water quality, filtering surface water, storing floodwater and creating or enhancing wildlife habitat.
Located in
News & Events
-
Executive Order -- Preparing the United States for the Impacts of Climate Change
-
President Obama signed an executive order that will begin to prepare the Nation for the impacts of climate change by undertaking actions to enhance climate preparedness and resilience.
Located in
News & Events
-
'Climate Hubs' Will Provide Regional Networks on Climate Science, Forecasting Impacts as Part of President's Climate Action Plan
-
Agriculture Secretary Tom Vilsack announced today the creation of the first ever Regional Hubs for Risk Adaptation and Mitigation to Climate Change at seven locations around the country. "Climate Hubs" will address increasing risks such as fires, invasive pests, devastating floods, and crippling droughts on a regional basis, aiming to translate science and research into information to farmers, ranchers, and forest landowners on ways to adapt and adjust their resource management.
Located in
News & Events
-
AAAS Kicks Off Initiative to Recognize Climate Change Risks
-
AAAS is announcing the launch of a new initiative to expand the dialogue on the risks of climate change.
Located in
News & Events
-
Fracking Components Affect Thyroid Hormone Receptors
-
A subset of chemicals used in hydraulic fracturing can interfere with thyroid hormone receptors, according to a study presented at the joint meeting of the International Society of Endocrinology and the Endocrine Society.
Located in
News & Events
-
Monthly carbon dioxide levels hit new milestone
-
NOAA scientists reported that in March 2015 the monthly average global carbon dioxide level went above 400 parts per million for the first time.
Located in
News & Events
