Changes in Soil Properties and Quality for a Eucalyptus Introduction Area: A Case Study in Lancang County, Yunnan Province

摘要

Establishment of exotic species in the natural secondary forest and Pinus kesiya forest regions is common in Lancang County, southwestern Yunnan province, but their effects on soil properties and quality have not been fully studied. This research analyzed the effects of Eucalyptus plantation on soil physical and chemical properties, and evaluated the soil quality after Eucalyptus plantation replaced natural secondary evergreen broad-leaved forest and Pinus kesiya plantation. It was found that soil porosity, soil water content, soil pH, soil organic matter, exchangeable calcium, exchangeable magnesium and microelement decreased, soil bulk density increased and soil aeration permeability became very low after establishment of Eucalyptus . However, with forest litter retained, the contents of soil N, P and K had been rising in the case of applying fertilizer at the initial stage of Eucalyptus introduction. The soil quality indexes ( SQI ) under Eucalyptus plantation were lower than those under the natural secondary evergreen broadleaved forest and Pinus kesiya plantation. The SQI of soils in Eucalyptus plantation which replaced Pinus kesiya plantation lands (SQI = 0.208) was lower than that of soils in Eucalyptus plantation which replaced natural secondary evergreen broad-leaved forest lands (SQI = 0.269). The study results showed that replacement of natural secondary evergreen broad-leaved forest and Pinus kesiya plantation by Eucalyptus plantation has changed soil properties and lowered soil quality. The secondary evergreen broad-leaved forest vegetation that restored naturally is more favorable to maintaining and improving soil quality