Temperature-dependent body size effects determine population responses to climate warming

Area of Science:

• Ecology
• Climate Change Biology
• Physiological Ecology

Background:

• Ecological models often assume biological rates scale independently with body size and temperature.
• Empirical evidence suggests interactive effects between body size and temperature on vital rates are common.
• This assumption limits our understanding of animal population responses to warming.

Purpose of the Study:

• To investigate the consequences of interactive temperature- and size-scaling of vital rates on population dynamics under warming.
• To assess how these interactions alter population regulation, stage-structure, and community structure.
• To determine if size-temperature interactions in metabolic rate scaling are prevalent in fish populations.

Main Methods:

• Utilized a stage-structured consumer-resource model to simulate population dynamics.
• Incorporated interactive scaling of vital rates with both body size and temperature.
• Analyzed experimental data on metabolic rate scaling for 20 fish species.

Main Results:

• Interactive scaling of vital rates significantly alters population and stage-specific responses to rising temperatures.
• Warming, under interactive scaling, can induce shifts in population regulation and stage-structure.
• Size-temperature interactions in intraspecific metabolic rate scaling were found to be common in fish.

Conclusions:

• Accounting for size-specific temperature effects is pivotal for accurately understanding how warming impacts animal populations and communities.
• Current assumptions of independent scaling may lead to inaccurate predictions of ecological responses to climate change.
• The prevalence of size-temperature interactions highlights the need for more complex, size-structured models in ecological forecasting.