Changes in soil carbon sequestration in Pinus massoniana forests along an urban-to-rural gradient of southern China

[摘要] Urbanization is accelerating globally, causing a variety of environmentalchanges such as increases in air temperature, precipitation, atmosphericCO₂, and nitrogen (N) deposition. However, the effects of these changeson forest soil carbon (C) sequestration remain largely unclear. Here, we usedurban-to-rural environmental gradients in Guangdong Province, southern China,to address the potential effects of these environmental changes on soil Csequestration in Pinus massoniana forests. In contrast to ourexpectations and earlier observations, soil C content in urban sites wassignificantly lower than that in suburban and rural sites. Lower soil C poolsin urban sites were correlated with a significant decrease in fine rootbiomass and a potential increase in soil organic C decomposition. Variationof soil C pools was also a function of change in soil C fractions. Heavyfraction C content in urban sites was significantly lower than that insuburban and rural sites. By contrast, light fraction C content did not varysignificantly along the urban-to-rural gradient. Our results suggest thaturbanization-induced environmental changes may have a negative effect onforest soil C in the studied region.

[学科分类] 地球化学与岩石