Stronger El Niños reduce tropical forest arthropod diversity and function.

Area of Science:

• Ecology
• Climate Change Biology
• Conservation Biology

Background:

• Arthropods are hyper-diverse in the tropics, providing crucial ecosystem functions.
• Tropical arthropod communities are understudied compared to temperate regions.
• Climate change impacts on arthropods, particularly tropical species, are debated.

Purpose of the Study:

• To investigate the long-term impacts of climate change, specifically intensified El Niño events, on tropical forest arthropod diversity and function.
• To correlate arthropod diversity changes with ecosystem functions like decomposition and herbivory.
• To assess the vulnerability of tropical arthropods to climate change-driven phenomena.

Main Methods:

• Time-series analysis of data from primary tropical forests.
• Correlation analysis between El Niño occurrence, species loss, and species traits (feeding, specialization).
• Comparison of impacts across continents (Americas, Southeast Asia).

Main Results:

• Long-term declines in arthropod diversity and function were linked to El Niño events.
• Species losses in the Americas correlated with El Niño sensitivity; abundant species fluctuated by feeding traits and specialization.
• Observed arthropod diversity changes correlated with altered rates of decomposition and leaf herbivory.

Conclusions:

• Intensified El Niño events pose an immediate threat to tropical forest arthropods and ecosystem functions.
• Widespread changes in arthropod communities could fundamentally alter tropical forest ecosystems.
• Long-term monitoring and mechanistic research are essential to address this novel threat to tropical biodiversity.