Management of indigenous plant-microbe symbioses aids restoration of desertified ecosystems

Disturbance of natural plant communities is the first visible indication of a desertification process, but damage to physical, chemical, and biologica l soil properties is known to occur simultaneously. Such soil degradation l imits reestablishment of the natural plant cover. In particular, desertific ation causes disturbance of plant-microbe symbioses which are a critical ec ological factor in helping further plant growth in degraded ecosystems. Her e we demonstrate, in two long-term experiments in a desertified Mediterrane an ecosystem, that inoculation with indigenous arbuscular mycorrhizal fungi and with rhizobial nitrogen-fixing bacteria not only enhanced the establis hment of key plant species but also increased soil fertility and quality. T he dual symbiosis increased the soil nitrogen (N) content, organic matter, and hydrostable soil aggregates and enhanced N transfer from N-fixing to no nfixing species associated within the natural succession. We conclude that the introduction of target indigenous species of plants associated with a m anaged community of microbial symbionts is a successful biotechnological to ol to aid the recovery of desertified ecosystems.