There is a lot going on in the ground under our feet: earthworms, ants and termites crawl and crawling through and on the floor and are among the most ecologically important soil inhabitants. They mix the floor, serve as food and create habitats for other animal species with their buildings. To what extent these three species influence the soil and improve its properties, researchers have now analyzed.
Earthworms, ants and termites occur all over the world and make up a significant proportion of invertebrates in their number as well as in their biomass. Your mounds and underground passages change the microclimate of the soil and help both plants and other animals with nutrients and food. So far, studies that deal with the effects of these floor dwellers have only dedicated themselves to individual species, locations and ecosystems.
Soil dwellers improve many soil properties
A research team led by Donghao Wu from Sun Yat-Sen University has now analyzed the floor-improving effect of these three groups invertebral in various ecosystems in a meta-analysis. The team evaluated 1,047 studies from six continents and examined the effects of termites, ants and earthworms on 47 ecosystem properties. The properties examined include chemical parameters and soil nutrients, such as the nitrogen content, as well as physical soil parameters such as the moisture content. Processes of the nutrient cycle such as decomposition and biological factors such as plant diversity were recorded.
The evaluations showed that the presence of the three ground animal groups25 of the 47 ecosystem properties significantly improved – including ten for soil nutrients, four for plants and two for microorganisms. Above all, the soil residents helped increase the biomass of microorganisms: termites increased the biomass by 151 percent, ants by 73 percent and earthworms by 45 percent. But they also increased the biomass of plants, especially the termites with 75 percent.
Good for the climate and plant growth
But soil breathing also improved through the activity of the three invertebrates, as WU and his team found. Termitte increased soil breathing by 131 percent, ants by 81 percent and earthworms by 68 percent. Since termites live primarily in warmer climate zones, their positive effect on soil breathing was particularly detectable in the tropics. This is an important result, because earlier studies suggested that termites could decompose more wood due to climate change and thereby counteract the CO2-storing effect of wood and trees. Due to its ability to improve soil breathing, more CO2 could be saved in the ground to compensate, as the researchers explain.
Termitte and ants also support plant growth by increasing the content of important nutrients in the soil – especially in tropical and moderate climate zones. Termitte hills primarily promote the phosphorus content and ants hill in the nitrogen content in affected soils. “These results indicate that invertebrate soil creatures make a significant contribution to natural carbon binding in terrestrial ecosystems,” explains co -author Nico Eisenhauer from the German Center for Integrative Biodiversity Research.
Support for drought
The research team also found that termites and earthworms support the plants in dry phases. According to drought events in tropical rainforests, termites were, for example, more active. This improved the soil moisture, the survival rate of young plants, the decomposition rate of wood and the nutrient heterogeneity of the soil, such as WU and his colleagues. Earthworms are less common in dry regions, but when they occur, their graving enables the plant roots to better achieve nutrients from deeper layers of soil.
However, climate change could destroy these positive effects because it harms terms, ants and earthworms: “We know that global climate change with its extreme events and the intensification of land use threaten ants, earthworms and termites. It is time to recognize its importance for the functioning of ecosystems and protect them accordingly, ”says Eisenhauer.
Source: German Center for Integrative Biodiversity Research; Specialist articles: nature, DOI: 10.1038/S41586-025-08594-Y