Effects of litter removal on soil organic carbon mineralization and temperature sensitivity of Pinus sylvestris var.mongolica forest in urban park

Litter is an important source of soil organic matter. The changes of its quantity and quality influence the mineralization of soil organic carbon. The fallen leaves of trees in urban parks are often cleaned up as garbage, which leads to soil barrenness and affects the stability of organic carbon mineralization and its temperature sensitivity, and thus may impact global climate change. In this study, the forest understory soil of Pinus sylvestris var. mongolica in Changchun Park, Changchun City, Jilin Province was selected in order to explore the effects of litter removal on forest soil chemical properties and soil organic carbon mineralization and its temperature sensitivity as well. The results showed that the removal of litter changed the soil chemical properties, soil organic carbon mineralization rate and its temperature sensitivity of Pinus sylvestris var. mongolica forest. Soil pH, C/N ratio and electrical conductivity decreased; total phosphorus, total nitrogen, soil organic carbon, easily extracted glomalin-related soil protein and total glomalin-related soil protein increased. The content of total nitrogen was with the most obvious change, increasing by 53.1%. After litter removal, soil organic carbon mineralization rate, accumulation CO₂ emissions and SOC mineralization temperature sensitivity coefficient (Q₁₀) increased with the increase in temperature. Specifically, after litter removal at 10 ℃, 20 ℃ and 30 ℃, the SOC mineralization rate of Pinus sylvestris var. mongolica forest increased by 1.17%, 8.4% and 16.4%, the cumulative CO₂ emissions of SOC mineralization increased by 6.70%, 1.98% and 9.67%, respectively. The temperature sensitivity coefficient (Q₁₀) of SOC mineralization increased by 0.51% and 8.99% at 20 ℃/10 ℃ and 30 ℃/20 ℃, respectively.