Restoring a Degraded Riparian Forested Buffer While Balancing Phosphorus Remediation, Biodiversity, and Indigenous Land Access

Abstract

This research tested whether mycorrhizae can rejuvenate the water quality and pollinator functions of degraded riparian forested buffers (RFBs) in agricultural landscapes while facilitating indigenous Abenaki access to ancestral lands. Two plots within a degraded RFB were restored with a multi-functional plant community, one plot inoculated with commercial mycorrhizae and the other without. A control plot remained in a degraded state dominated by the invasive shrub Rhamnus cathartica. The restoration palette of 32 plants included 28 species useful to the Abenaki, representing opportunities for phosphorus removal through harvesting. Monitoring data from 2020 to 2023 indicated consistently greater plant diversity in the restored plots, with 58 newcomers appearing. Although the total phosphorus (P) decreased over time in all the treatments, the greatest decrease was in the uninoculated plot, likely due to pathogenicity from the commercial inoculant or the spatial variability of soil and light. The biomass P of five plant species differed among the species but not among the treatment plots. Nonetheless, Abenaki harvesting removed P and can be an effective form of phytoremediation, phytoextraction. However, this research revealed trade-offs between P mitigation, indigenous use, and pollinator functions of the RFB. Fostering higher biodiversity, Indigenous land access, and P mitigation are important solution-oriented aims to balance when restoring degraded RFBs.