Dynamic characteristics of litterfall and nutrient return of four typical forests along the altitudinal gradients in Mt. Shennongjia, China
神农架海拔梯度上4种典型森林凋落物现存量及其养分循环动态

To explore the litterfall and their seasonal dynamics of the four typical forests along the altitudinal gradient in Mt. Shennongjia, Hubei. We measured litterfall of Evergreen broad-leaved forest (EBF), Mixed evergreen and deciduous broad-leaved forest (MF), Deciduous broad-leaved forest (DBF), and sub-alpine coniferous forest (CF) in Shennongjia. Litterfall collection was conducted monthly from September 2009 to January 2011. The result showed that the total annual litterfall of the four typical forests along the altitudinal gradient in Mt. Shennongjia was increased and then decreased along the altitude. The annual amounts of EBF was 6 807.97 kg/hm2, MF 7 118.14 kg/hm2, DBF 6 975.2 kg/hm2 and CF 4 250.67 kg/hm2. The seasonal dynamics of litterfall iccurred two peaks during the periods from April to May and November annually. The returns of N from the littlefall of four forests along the elevation gradients were 132.06, 162.29, 157.12 and 185.77 kg/hm2, and that of P was 4.62, 4.39, 8.24 and 4.15 kg/hm2.