Lower carbon fractions and microbial carbon use efficiency in ant-mound surface soils than in adjacent biocrusted soils of a revegetated desert

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides insights into the role of ants in dryland carbon cycling, useful for refining soil carbon models and understanding biocrust contributions.

🏢実務担当者:Limited direct application, but relevant for companies involved in land restoration or carbon offset projects in dryland regions.

🏛政策担当者:May inform policies on dryland restoration and carbon accounting, emphasizing the need to include faunal disturbances in carbon stock estimates.

Drylands are key components of the global carbon cycle, and biological soil crusts (biocrusts) are important secondary groups of primary producers. Ants are among the most abundant soil-dwelling animals in drylands; however, the relationship between ant nesting activity and the surface soil carbon cycle in biocrust systems remains unclear. In a revegetated area of the Tengger Desert, we compared five surface (0–5 cm) microhabitats (ant-mound soil, the biocrust and soil beneath mounds, and adjacent control biocrust and soil) in terms of physicochemical properties, 12 carbon fractions, 13 C-glucose-based microbial carbon use efficiency (CUE), and greenhouse-gas fluxes under standardized laboratory incubation. Compared with the control surface soil, ant-mound soils exhibited significantly lower water content, pH, and nutrient content, as well as a coarser texture. Mound soils also contained significantly less soil organic carbon (−62%), microbial biomass carbon (−63%), and labile fractions (e.g., particulate organic carbon − 69% and easily oxidizable carbon − 66%), as well as a significantly lower microbial CUE (0.305 vs. 0.418; −27%). During incubations, intact biocrust plus its underlying soil acted as a net CH 4 sink (−2.9 to −3.7 µg C kg −1 d −1 ), whereas mound and exposed surface soils were net CH 4 sources (+3.2 to +4.8 µg C kg −1 d −1 ); N 2 O efflux was higher in mound soil than in control surface soil, although control biocrust showed comparably high N 2 O. Because ant nest sites are not chosen at random, we interpret these contrasts as associations that may arise from nest construction, pre-existing site differences, or both. Ant mounds occupy only approximately 0.12% of the surface; therefore, their contribution to landscape-scale fluxes is small; the principal finding is a consistent surface-soil contrast showing that ant nesting is associated with lower near-surface carbon storage and microbial carbon-use efficiency in biocrust-covered drylands. Explicitly accounting for such faunal surface disturbance would improve assessments of biocrust carbon accrual in dryland restoration.

• openalex https://doi.org/10.1016/j.geoderma.2026.117948first seen 2026-08-01 05:47:57