Abstract:

Throughfall,canopy interception and stemflow in Pinus massoniana forest were studied. The results showed:During the most rainfall period from May to August,the ratios of throughfall,canopy interception and stemflow accounted for total amount rainfall were more than half. The rainfall redistribution of P.massoniana was closely related with precipitation characteristics. The throughfall,interception and stemflow of P.massoniana positively related with precipitation amount. Under different rainfall intensity events,the ratios of throughfall and stemflow increased,but interception rate decreased as rainfall intensity increased. All the maximums of throughfall appeared in the ≥90.0 mm rainfall amount and 3.0～4.0 mm·h^-1 rainfall intensity. All the maximums of interception rate appeared in the <10.0 mm rainfall amount and <1.0 mm·h^-1 intensity. All the maximums of stemflow rate appeared in the 60.0～70.0 mm rainfall amount and 2.0～3.0 mm·h^-1 rainfall intensity. Throughfall rate below the canopy had clearly spatial variation and throughfall rate at positions closest to the trees was higher than those under the peripheral part. Spatial variation of throughfall rate below the canopy (I.e., the CV of throughfall ratio) decreased with increasing rainfall. The stemflow of P.massoniana was positively correlated with diameter at breast height and crown area.

Key words: Pinus massoniana, rainfall redistribution, canopy interception, stemflow, throughfall