Partitioning the Apparent Temperature Sensitivity into Within- and Across-Taxa Responses: Revisiting the Difference...

Area of Science:

• Ecology
• Environmental Science
• Microbiology

Background:

• Conventional ecological analyses suggest heterotrophs are more thermally sensitive than autotrophs.
• This implies that rising temperatures could disrupt trophodynamics and carbon fluxes.
• Previous studies often conflate within- and across-taxa responses.

Purpose of the Study:

• To differentiate between within- and across-taxa thermal sensitivity in protists.
• To test the 'hotter-is-partially-better' hypothesis in ecological contexts.
• To clarify the drivers of apparent thermal sensitivity differences between autotrophs and heterotrophs.

Main Methods:

• Separated within-taxa and across-taxa analyses of thermal sensitivity.
• Examined responses in autotrophic and heterotrophic protist communities.
• Quantified the contribution of within-taxa trends to overall thermal sensitivity.

Main Results:

• 92% of the observed difference in thermal sensitivity between autotrophic and heterotrophic protists is due to within-taxa responses.
• Biochemical relationships show a positive correlation between temperature and growth rate within taxa.
• Inter-taxa fitness differences offer only partial compensation for these within-taxa effects.

Conclusions:

• The study underscores the critical importance of distinguishing within- and across-taxa responses for accurate ecological interpretations.
• Findings support the 'hotter-is-partially-better' hypothesis, indicating warming can enhance growth up to a point.
• Accurate understanding of thermal sensitivity is crucial for predicting climate change impacts on trophic dynamics and biogeochemical cycles.