Microhabitats reduce animal's exposure to climate extremes

Area of Science:

• Ecology
• Climate Change Biology
• Herpetology

Background:

• Extreme weather events pose significant threats to wildlife survival by exceeding physiological limits.
• Organismal survival during climate extremes depends on access to suitable microhabitats that buffer harsh environmental conditions.
• Understanding the thermal buffering capacity of microhabitats is crucial for predicting species' vulnerability to climate change.

Purpose of the Study:

• To investigate the effectiveness of various microhabitats in buffering extreme temperatures in Philippine rainforests.
• To compare microhabitat temperatures with the critical thermal maxima (CTmax) of inhabitant frog and lizard species.
• To assess the influence of microhabitat buffering on the projected vulnerability of animal communities under future climate change scenarios.

Main Methods:

• Collected temperature data from four microhabitats (soil, tree holes, epiphytes, vegetation) and macrohabitat controls in primary rainforests.
• Measured the critical thermal maxima (CTmax) of resident frog and lizard species.
• Modeled the impact of uniform and non-uniform temperature increases on community vulnerability with and without microhabitat buffering.

Main Results:

• Microhabitats reduced mean temperatures by 1-2°C and extreme temperature duration by 14-31 times compared to macrohabitats.
• Microhabitat temperatures remained below the CTmax of frogs and lizards, while macrohabitat temperatures often exceeded lethal levels.
• Microhabitat buffering reduced projected community vulnerability by up to 32-fold under uniform warming and 108-fold under non-uniform warming.

Conclusions:

• Microhabitats possess substantial potential to buffer climate extremes and mitigate mortality during extreme weather events.
• Macroclimate-based predictions assuming uniform microclimate changes may overestimate species' vulnerability to climate change.
• Despite buffering, even non-uniform temperature increases within microhabitats could still pose a threat to sensitive species like frogs and lizards.