Science Advances: Standing biomass estimates of arthropods could improve understanding of food webs

Scientists have revealed and elaborated on the global biomass and population of insects and other arthropods in a research article published by Science Advances in early 2023. 

The research team was led by the Weizmann Institute of Science's Yuval Rosenberg and Yinon Bar-On and featured Amir Fromm, Meital Ostikar, Aviv Shoshany, Omer Giz and Ron Milo.

The team analyzed thousands of evaluations from approximately 500 sites worldwide and estimated that there are approximately 1 x 10¹⁹ soil arthropods on Earth, with approximately 95% of them being soil mites and springtails. 

The soil contains approximately 200 million metric tons (Mt) of dry biomass, with termites contributing approximately 40% of its biomass and ants contributing approximately 10%. The current global biomass of above-ground arthropods is unknown and requires further research.

The team estimates that the combined dry biomass of all terrestrial arthropods is approximately 300 Mt, with the uncertainty range spanning from 100 to 500. The total is similar to the mass of humanity and its livestock. 

The new information will enhance scientists' understanding of arthropods in terrestrial ecosystems and provide a benchmark for those studying their decline.

"For example, the knowledge of the global biomass distribution of termites allows estimating their contribution to global warming through the greenhouse gases they produce," the article says. "Likewise, standing biomass estimates of arthropods may improve our understanding of food webs and of possible effects of declines in arthropod numbers."

"We estimate the global biomass and population size of terrestrial arthropods and provide a holistic view of their taxonomic composition and distribution," the report continues. "This collection reveals the current state of quantitative knowledge on the global abundance of arthropods and highlights key knowledge gaps, which future research should help close."