Ecosystem degradation may reduce biodiversity, including plants and fungi. Although restoration ecologists rarely specify fungal restoration as a desired outcome, restoration methods may either promote or inhibit fungi. Direct fungal restoration may provide benefits to ecosystems and support restoration efforts, but little is known about how either degradation or restoration affect fungi.
We investigated how fungi respond to habitat fragmentation in coastal sage scrub (CSS) ecosystems. Using molecular and fluorimetric techniques, we found that leaf-litter fungal activity declined in smaller fragments with less diverse vegetation. We manipulated plant litter diversity using litter bags and found less mass remaining in litter bags containing more diverse litter. Moreover, these litter bags harbored greater numbers of fungal taxa. Our findings suggest that plant diversity controls decomposer fungal diversity and function in fragmented ecosystems.
Fragmented landscapes are particularly vulnerable to plant invasions. Both invasive plants and invasive removal methods may harm native plants and fungi. Within invaded CSS ecosystems, we compared invasive plant removal methods, monitored plant communities, and extracted soil fungi. While both herbicide and mowing reduced invasive cover, neither method promoted native plant recovery. Herbicide however had the added benefit of facilitating fungal recovery.
Mycorrhizal fungal recovery may support restoration outcomes by providing benefits to plants. However, it is unclear whether directly manipulating mycorrhizal fungi via inoculation has consistent effects across ecosystems or long-term effects on colonization, and whether types of inocula differ in their effectiveness. We synthesized data from restoration studies across ecosystems to examine the effects of inoculation on mycorrhizal establishment and plant growth under field conditions. We found that inoculation consistently increased mycorrhizal abundance across ecosystem types and improved growth and establishment of plants long-term. Both fungi from reference ecosystems and species-specific inoculum improved mycorrhizal associations with plants more than did commercial fungi.
Landscape degradation inhibits certain groups of fungi that either cycle nutrients or support plants. Depending on the method used, restoration may either not have any effect on fungi or may promote fungal recovery. We conclude that incorporating fungi into restoration efforts may better facilitate the establishment of both belowground and aboveground components of ecosystems.