Urban–rural gradients in soil nutrients beneath Chinese pine (Pinus tabulaeformis Carr.) are affected by land-use

Urban–rural gradients of soil nutrients may be affected by many factors including land use, vegetation cover, and management. In this study, focusing on one vegetation type (Chinese pine, Pinus tabulaeformis Carr.) to exclude the effects of vegetation cover, we investigated soil nutrients in three land-use types (neighborhoods, parks and roadsides) along urban–rural gradients in Beijing, China, to explore the differences in soil nutrients across land-use types and the changes of soil nutrients along the urban–rural gradient. Soil nutrients (organic carbon, calcium and magnesium) are significantly higher in neighborhoods and parks than in roadsides, while soil nutrients (except for magnesium) showed no significant differences between in neighborhoods and in parks. Interestingly, soil moisture, nitrate-nitrogen, calcium, magnesium, and available phosphorus and potassium all decreased along urban–rural gradients in parks, while only soil available phosphorus did so in neighborhoods and none soil variables studied showed this trend in roadsides. Thus, land use plays an important role in modifying urban–rural gradients of soil nutrients.