Soil Homogenization Modifies Productivity, Nitrogen Retention and Decomposition in Restored Grassland

摘要: At the local (within site) scale, soil heterogeneity can influence ecosystem function. However, in former agricultural systems, be low as a legacy of tillage (that is, via process homogenization). We investigated relationship between homogenization and three functional response variables—aboveground productivity, nitrogen retention (assessed 15N tracer addition) plant litter decomposition using bags)—during first 2 years following tallgrass prairie restoration field. compared plots with substrate (topsoil patches enriched sand or woodchips) homogeneous that contained same overall ratios component materials. also topographic (pits mounds) flat plots. The variables varied significantly homogenization, but effect depended on type (sand vs. woodchips microtopography), which was consistent these sources having variable effects water nutrient availability. Soil reduced aboveground productivity by 50% for woodchip treatment, it had opposite topography treatment. Homogenization treatment 50%, rate increased 8%. Overall, variation were associated relative abundances forbs grasses. latter results suggest function may occur indirectly result its community assembly. Moreover, forb N along mound edges differed from means adjacent patches, revealed complementarity microsite contribute to