Consequences of agricultural deforestation and subsequent afforestation on soil biodiversity and ecosystem multifunctionality

The Earth is currently in an era where massive deforestation and afforestation coexist. The impact of large-scale agricultural deforestation and the subsequent afforestation on soil biota multidiversity, ecosystem multifunctionality (EMF), and the relationship between soil biota multidiversity and EMF (BEFm) remain unclear. Here, we investigate 405 paired plots along a 4000 km south-north transect, spanning tropical, subtropical, temperate, and boreal zones. We measure 19 ecological functions and sequence soil biota (including bacteria, fungi, archaea, viruses, protists, and invertebrates) and metagenomes. We find that agricultural deforestation reduces soil multitrophic biodiversity by 25% and EMF by 58%, and afforestation has partially restored them, but pristine levels have not been reached. Agricultural deforestation decouples the positive BEFm relationship across four climatic zones, while afforestation restores the positive BEFm relationship in tropics and subtropics but not in temperate and boreal zones. Afforestation in the warmer zone triggers potential multitrophic cascades to enhance EMF, thereby strengthening BEFm relationship. The changes in biogeochemical-cycling genes induced by afforestation exert more significant driving effects on EMF in the warmer zone than the colder zone. Our study provides integrative evidence that climate modulates the recovery of BEFm relationship and offers multitrophic and metagenomic insights into the mechanisms underlying EMF. Large-scale deforestation and afforestation currently coexist. Along a 4,000 km transect, Yu et al. show that deforestation reduces soil multi-diversity by 25% and ecosystem multifunctionality by 58%, while afforestation partially restores both.