Influence of Solidago canadensis L.on the physi-chemical properties of soil,main microorganisms,soil nutrients and heavy metal contents in 0-20 cm cultivated layer were studied by field investigation and sample analysis.Soil samples were collected under four disturbing modes(abandonment of cultivation,shrubbery,chemical control,ploughing)from 5 plots,i.e.Solidago canadensis L.massively invaded region,paddy field(CK),shrubbery,chemical treated field after Solidago canadensis L.invasion and tillage soil of invaded region in Changsha County.The re...