Fine-scale soil heterogeneity at an urban site: implications for forest restoration

Soils within a forested park in New York City, NY, USA, were sampled to evaluate spatial variation in pH on a disturbed forest restoration site, and compare soil physicochemical parameters (pH, texture, moisture, organic matter [OM], plant available Mg, Ca, Mn, Al, Fe, K, Na, P, Cu, and Zn) between the restoration site and an intact forest. The divergence of soil parameters between sites suggests that forest clearing on the restoration site initiated the erosion of fine particles and altered soil chemistry. Within the restoration site, the spatial pattern, and correlation with base-cations, suggests that localized impacts from the built environment drive fine-scale pH variation with implications for nutrient availability and native plant establishment. The majority of our site was found to be unsuitable for native species adapted to acidic soils. However, sampling points spaced less than 10 m apart can capture the pH variation and allow for the identification of acidic soil patches.