Soil Carbon And Nutrient Dynamics Following Cessation Of Anthropogenic Disturbances In Degraded Subtropical Forests

Subtropical forest (Public Domain Pictures)

Soil carbon (C) and nutrients are fundamental to forest biodiversity and function. Forest degradation has led to the reduction in soil C and nutrients in global forests, particularly in a tropical biome where human population density is high. Ecological restoration of degraded forests can increase soil C and nitrogen (N), but the dynamics of plant essential nutrients such as phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in soil following restoration, however, are largely unknown.

In a recent paper published in Land Degradation & Development (Feng et al. 2017), researchers from Anhui Agricultural University in China and Lakehead University in Canada studied how soil pH, bulk density, organic matter, water content, C stock and C, N, P, K, Ca, and Mg concentrations changed over time following the cessation of anthropogenic disturbances in subtropical forests in China. They also examined how the stoichiometric (mass concentration) ratios of C vs. nutrients and N vs. P respond over time following the cessation of anthropogenic disturbances.

The study found that stand basal area, soil water content, organic matter content, and C concentration and stock increased, while soil pH and bulk density decreased over time, with the most pronounced effects in topsoil layer. Total and available N and K, as well as available P and total Mg, increased, but total P in the 20-30 cm layer and Ca in all soil layers decreased over time. The mass concentration ratios of soil C to total N and available N, P, and K decreased, whereas those for C to total P and Ca as well as total N to total P and available N to available P increased over time.

The findings of the study indicate that C and biologically driven nutrients increase, and geochemically driven nutrients in soil decrease, while plant biomass accumulates following restoration. This study suggests that ecological restoration through the cessation of anthropogenic disturbances in degraded mountain forests increase ecological functions and prevent soil nutrient loss.

The study, Soil Carbon and Nutrient Dynamics Following Cessation of Anthropogenic Disturbances in Degraded Subtropical Forests was recently published in the journal Land Degradation & Development.