Abstract:

In this study, storage and composition of fallen wood were investigated by sampling in a fixed area plot in a natural secondary Pinus tabulaeforims forest at Huoditang forest region in the Qinling Mountains. The fallen wood mass in the region was 8.25 t·hm^-2, of which P. tabulaeformis and Toxicodendron vernicifluum accounted for 69.58% and 30.42%, respectively. The storage of fallen wood investigated according to an international classification showed that the storage of decay class Ⅱ was dominant, accounted for 42.06% of the total, and the storage of decay class Ⅴ accounted for only 8%. The relationship of density and decomposition was simulated by monomial exponential attenuation model, and the decomposition constant of P. tabulaeformis fallen wood was 0.039 93 (R^</em>2=0.98178), while that of T. vernicifluum fallen wood was 0.045 33 (R^</em>2=0.982 68). The monomial exponential attenuation model predicted that it would take 17 and 75 years to decompose 50% and 95% of P. tabulaeformis fallen wood, and take 15 and 66 years to decompose 50% and 95% of T. vernicifluum fallen wood.

Key words: Qinling Mountains, natural secondary Pinus tabulaeformis forest, fallen wood, storage, decomposition, monomial exponential attenuation model