Abstract:

Forested areas of eastern China are predominatly evergreen broad_leaved forests which are typically zonal or climatic climax vegetation in subtropical areas, dominated by Castanopsis fargesii Franch.(Fagaceae)，a shade-tolerant and long-lived species. The observation and study of its reproductive characteristics in the field still remain poorly understood. Based on the methods of Randomized Branch Sampling and observation of labeled individuals, the flowering phenology, flower number and spatial distribution of Castanopsis fargesii Franch. from the Schimeto-Castanopsietum fargesii Association in the Tiantong National Forest Park (TNFP) were studied in this paper. The results showed that the floral bud flushing and inflorescence elongation of C. fargesii emerged at end of April and the trees flowered after leaf emergence. The onset of mass flowering occurred at late May, and its duration within population could last more or less eight days, while the flowering time among individuals experienced less difference. The refore C. fargesiidisplays synchronous flowering. Given the lower precipit ation and gradually increasing temperature during April_May, synchronous flowering and therefore pollination in C. fargesii is a beneficial adaptation. Floral buds commonly located at the first-order branch, which made up 91.92% of all the reproductive branch, nearly 7.07% and 1.01% at the second and the third branch, respectively. There was an apparent difference between the floral bud initiation at the toward-sun reproductive branch and the toward_shade ones within a crown (p<0.01) and the floral bud initiation were 78%±5.7% and 67%±5.7% respectively. Within a crown, there were about 4.89±1.82 panicles per reproductive branch at sun-side and 3.08 ±2.08 at shade-side.The number of male inflorescence of C. fargesii is more than that of the female and male inflorescence occupied 77.9% of the total and female inflorescence 22.1% respectively. There were 67.9±16.7 staminate at one male inflorescence and 26.1 ±5.08 pistillate at one female inflorescence. Furthermore, the flower numbers were male biased during spring censuses and the ratio of staminate to pistillate was about 9.2∶ 1.Mass staminate could produce higher pollen concentration during synchronous period 2.and should increase the pollination efficiency. Therefore flowering in spring exerted 3.great influence on the reproductive output ofC. fargesii.