Consequences of aboveground invasion by non-native plants into restored vernal pools do not prompt same changes in belowground processes

: Given the frequent overlap between biological plant invasion and ecological restoration efforts it is important to investigate their interactions to sustain desirable plant communities and modify long-term legacies both above and belowground. To address this relationship, we used natural reference, invaded, and created vernal pools in the Central Valley of California to examine potential changes in direct and indirect plant effects on soils associated with biological invasion and active restoration ecosystem disturbances. Our results showed that through a shift in vegetation composition and changes in the plant community tissue chemistry, invasion by non-native plant species has the potential to transform plant inputs to soils in vernal pool systems. In particular, we found that while invasive plant litter decomposition was driven by seasonal and interannual variability, associated with changes in precipitation, the overall decomposition rates for invasive litter was drastically lower than native species. This shift has important implications for long-term alterations in plant-based inputs to soils in an amplifying feedback to nutrient cycling. Moreover, these results were independent of historic active restoration efforts. Despite the consistent shift in plant litter decomposition rates and community composition, we did not detect associated shifts in belowground function associated with invasion by non-native plants. Instead, soil C:N ratios and microbial biomass did not differ between invaded and reference naturally occurring pools but were reduced in the manipulated created pools independent of invasion levels. Our results suggest that while there is an observed invasive amplifying feedback aboveground this trajectory is not represented belowground, and restoration legacies dominated ten years after practices were applied. Restoration practices that limit invasive plant feedbacks and account for soil legacy recovery, therefore offer the best solution for disturbed ephemeral ecosystems. decomposition than native species, with decomposition of invasive non-native grass litter driven by season and changes in interannual precipitation. These findings suggest that aboveground community structure shifts to favor invasive dominated species has the potential to impact plant inputs to belowground processes over long-term shifts in plant inputs to soils. potential there, instead, we found that legacies resulting from vernal were stronger drivers invasion and belowground function suggests that aimed controlling however additional efforts may be appropriate to account for legacy effects of restoration on belowground processes. our vernal pools. However, this study illustrates the opportunity to limit long-term effects of altered aboveground plant-soil feedbacks in directing belowground processes should additional restoration occur. The importance of this time lag in establishing altered community feedbacks within the ecosystem provides a window of opportunity for adaptive management practices aimed at ecosystem recovery.