Effects of Altitude on Growth and Yield in Carya cathayens

In order to scientifically guide extension and planting of Carya cathayens,effects of altitude on yield,diameter at breast height,and height were analyzed,by investigating mature C.cathayens forest in Ningguo City,Anhui Province,using plot method and fixing sample plant method.The results showed that yield was increased with a rise in altitude when altitude was below 550 m,but it was negatively correlated with altitude when altitude was above 550 m.Altitude was positively correlated with diameter at breast height,but negatively correlated with height.