Distribution and accumulation of trace elements in rhizosphere and non-rhizosphere soils on a karst plateau after vegetation restoration

Aims

The restoration of vegetation in the rocky desertified areas of karst plateaus is a major problem for present-day ecological studies. The aim of this study was to determine the effects of vegetation restoration on the distribution and accumulation of trace elements in rhizosphere and non-rhizosphere soils.

Methods

Four representative areas containing the plants Coriaria nepalensis Wall., Pinus armandii Franch., Elaeagnus pungens Thunb., and Cotoneaster hissaricus Pojark. were selected within a vegetation restoration area in the Karst Plateau of Caohai County, Guizhou Province, China. Soils were sampled using a grid method to measure the total contents of the trace elements iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in rhizosphere and non-rhizosphere soils.

Results

The representative area containing Elaeagnus displayed the greatest amount of accumulation in the rhizosphere of both total and available trace elements, except for total Zn. Representative areas of the rhizosphere with other types of vegetation showed accumulation of only some of the trace elements studied. All types of vegetation were associated with the bioenrichment of available trace elements in both rhizosphere and non-rhizosphere soils, except for available Cu in areas associated with Cotoneaster.

Conclusions

Representative areas containing Pinus displayed the greatest degree of bioenrichment for both total and available trace elements in both rhizosphere and non-rhizosphere soils.