LAUSR

Abstract Restoration is difficult when topsoil and subsoil become mixed during pipeline construction. We studied soil properties, seedling emergence and establishment after pipeline construction in the Rio Grande Plains, Texas following physical (with or without erosion control blanket, ECB), chemical (humic substances, HS), and/or biological (native species mix) treatment. We documented higher soil water following precipitation under ECB; even with ECB soil water evaporated rapidly between rainfall events. Soil temperatures were cooler at mid-day under ECB on sunny days but similar on cool days and during evening. We observed from 3 to 8 more seedlings/0.09 m2 with ECB. Plots were dominated by exotic grasses after 2 years, likely because of seed bank and seed rain influences. The annual cover crop reduced exotic species biomass but did not negatively impact native species biomass. Pipeline construction affected all soil properties analyzed when compared to adjacent undisturbed areas; many soil properties changed on the pipeline following construction. Humic substances had no measurable effects. ECB enhanced seedling emergence but did not affect 2-year growing season biomass. Recommendations include proper seedbed preparation; ECB during periods of unfavorable conditions; use of locally-adapted species and an annual cover crop; and measures to preclude invasion of non-native species.