Fire-Derived Charcoal Attracts Microarthropods in the Litter of Boreal Deciduous Forest

Abstract

Larch forests in the permafrost zone of Eastern Eurasia are exposed to frequent wildfires, which are expected to increase with climate warming. However, little is known about how fire-derived charcoal is linked to the decomposition process in these forests. Fire-derived charcoal can affect the faunal communities in the forest litter. In a two-year field litterbag experiment, we investigated the effect of fire-derived charcoal on the colonisation by microarthropods (Collembola and Acari) of three decomposing litter species dominant in boreal larch forests. Charcoal addition led to an average 15% decrease in body size of collembola but significantly increased their abundance by 5 times throughout the experiment and acari by 1.5 times in the second year of decomposition, and this effect was consistent across all litter species. The increased microarthropod community may have hampered microbial activity and mass loss rate in the presence of charcoal. Charcoal altered the microarthropod community composition, increasing the proportion of collembola up to 20% compared to acari. The difference in abiotic conditions (increased litter water content during dry periods) induced by fire-derived charcoal was a more substantial factor determining the microarthropod community than litter species in the boreal larch forest. Our results indicate that fire-derived charcoal influences the biological drivers of decomposition in boreal larch forests, stimulating the growth of microarthropod community in decomposing litter.