Plant-soil feedbacks benefit plant invaders under multiple global change factors.

Plant-soil feedbacks (PSFs) are an important mechanism determining plant community dynamics and invasion by non-native species. While the individual responses of plants and soil microbes to multiple concurrent global change factors (GCFs) have been documented, it remains poorly understood how multiple GCFs affect PSFs and, particularly, whether this effect depends on plant origin. We conducted a PSF experiment with five pairs of native and alien species and nine GCFs applied in concurrent combinations of 0, 1, 3 and 6 GCFs. As GCF number increased, PSFs shifted from negative to neutral or positive in native species, but were consistently positive and became stronger in alien species. The positive response of PSFs to multiple GCFs was due to specific interactions between coacting GCFs in native species, but not in alien species, and was related to changes in soil mutualists. Our study highlights that PSFs could promote the spread of alien species under multiple concurrent GCFs.