Seasonal dynamics of pH and soil nutrients of Cunninghamia lanceolata forest after reconstruction with broadleaved trees
Cunninghamia lanceolata forest reconstruction was conducted using seedlings of Castanopsis hystrix,Michelia macclurel,Castanopsis fissa,Elaeocarpus sylvestris,Cinnamomum camphora,and soil nutrient dynamics was studied in five young Cunninghamia lanceolata stands after reconstruction with broadleaved trees from April 2008 to April 2009.The results showed that the soils of the five young stands were rather strong in acidity with the pH value ranged from 4.3 to 5.1,which firstly decreased,and then increased.Alkali-hydrolyzable N content decreased followed by a increase in 0-20 cm and 20-40 cm soil layers of C.hystrix stand,and in 0-20 cm soil layer of the stands of M.macclurel,C.fissa and E.sylvestris,whereas it decreased followed by an increase and then decreased again in 0-20 cm soil layer of C.camphora stand and 20-40 cm soil layer of the five stands.Available P content was relatively high in July and low in October in all stands,whereas available K content tended to decrease and then increased.Available nutrients in the 0-20 cm layer were higher than those in 20-40 cm layer.