AN CONTRAST ON THE CHARACTERISTICS OF SOIL IN THE NATURAL HABITAT AND RE SITE RESERVE OF TWO ENDEMIC SPECIES OF THE THREE GORGES RESERVOIR REGION OF YANGZI RIVER

A field study and experiments are carried out in details about the characteristics of the habitat and soil in the natural distributing region and planting site in the re-site reserve of the two endangered species of the Three Gorge Reservoir Region:Adiantum reniforme var.sinense and Myricaria laxiflora.It's suggested in the result that:Adiantum reniforme var.sinense prefers the warm,wet and well-drai-ning situation,in which case it has an acid clay with high degree of salt-leaching,high content of nutrients.Myricaria laxiflora,on the other hand, prefers the alluvial soil with sand and gravel in subtropics climate.The soil is of weak alkalinity, has low content of nutrient but moderate salt.The soil at the re site reserve in Wuhan Institute of Botany of Chinese Academia is a kind of neutral clay,which is deve loped from the deposit on lakeside.The content of the chief nutrients and salts are mainly between that of the soil samples from natural habitats of the two endangered species,and its contents of the trace elements are rather different from that of the soil in natural habitats of Adiantum reniforme var.sinense.