Ecosystem services from old-fields: Effects of site preparation and harvesting on restoration and productivity of traditional food plants

Abstract

Highly disturbed landscapes, including fallowed or abandoned farmland, are known to experience losses in native plant diversity that negatively impact the ecological functions and services provided by an ecosystem. The restoration of native species to the post-agricultural landscape using principles derived from indigenous knowledge could reverse this damage. This study examines the effects of three site preparation treatments (prescribed burning, tilling, and mowing) and biomass harvesting on the establishment and productivity of four native, edible, culturally-significant forbs (Apios americana Medik., Helianthus annuus L., Helianthus tuberosus L., and Oenothera biennis L.) restored to a fallow farm field. Species' responses to site preparation treatments varied over three years of observations, with plants grown from tubers establishing populations more successfully after burning or mowing and plants grown from seed establishing better after tillage. Harvesting of biomass after the first growing season reduced the number of individual plants observed for all restored species across all site preparation treatments but demonstrated the potential for production of traditional food resources in a low-management, multi-purpose agroecosystem. H. tuberosus showed particular promise for this purpose, producing an average of 881, 1397, and 1848 kg ha−1 of dry edible biomass on tilled, burned, and mowed plots, respectively. Burning was also found to enhance concentrations of organic matter, calcium, and magnesium in the soil, and many indicators of soil quality varied seasonally. These results indicate that with low-energy input management strategies, native wild edibles could be reintroduced into old-field systems to provide provisioning and cultural ecosystem services while maintaining or enhancing ecosystem function.