Research On Seed Fate Of Chinese Yew Taxus Chinensis Var. Mariei In TianMu Mountain

Seed rain and seed bank of a Chinese yew (Taxus chinensis var. mairei) population in Tianmu Mountain were researched in 2008 and 2009. The result conveyed as follows:1. With five mother trees as the research object, use the collection box to collect the seeds drop of mother trees. The seed rain lasted from 16th~23th of Oct. to 5th~14th of Dec., and the heaviest seed falling period was from Nov. 2nd to18th. The intensity of seed rain showed a great inter-annual variation, with a good harvest in 2008. The fallen seeds were composed of 49.9% proportion of immature seed, 33.8% proportion of chewed seed and 16.3% proportion of mature seed.2. Network selection method was conduct to analysis on the soil seed bank among 4 periods. The analysis on the soil seed bank under mother forest showed that the number of intact seeds was 122.75±108.08grain/m~2 in Oct., 279.25±210.73grain/m~2 in Dec. 2008, and 166.5±165.34grain/m~2 in Oct., 322.5±275.73grain/m~2 in Dec. 2009. The increased number of seed was 156.5±222.723grain/m~2 in 2008 and 156±275grain/m~2 in 2009, which showed a significant variation. Large number of intact seeds added into soil seed bank after seed rain each year. The number of intact seeds in soil seed bank decreased 112.75±47.74 grain/m~2 from Dec. 2008 to Oct. 2009. Large number of intact seeds lost from seed rot and seed predation by animals. The number of seeds in soil bank under bamboo forest was much lower than that of mother tree forest, and the increased number of seeds was 0.63±1.60 grain/m~2 in 2008 and 2.88±1.86grain/m~2 in 2009. This result showed a relatively subtle variation after seed rain, but significantly difference of seed density was occurred between Dec. 2008 and Oct. 20093. Total 14 animals were observed to visit Chinese yew, include 7 species were observed on the tree, 3 species of rodents captured by cage on the ground and 3 species of ants and 1 species of squirrels. Four bird species, Urocissa erythrorhyncha, Dendrocitta formosae, Spizixos semitorques, and Myophonus caeruleus, are responsible for long-distance dispersion of Chinese yew seeds. Nearly 800 grains seeds were eaten by these four birds during 10 days according to field observation. A total of 5.72±4.16 grain/m~2 seeds were eaten by Tamiops swinhoei and Callosciurus pygerythrus. Paguma larvata is another animal feed on a large of Chinese yew seed. Average quantity of seed in faeces of Paguma larvata were 134±17.46(n=15), ants responsible for seed disappear in Paguma larvata faeces and become important post-disperser of Chinese yew seed according to post-dispersal removal experiment. Feeding peak of animals occurred after the top time of seed rain and mostly concentrated in the middle slope. The total catch rate of rodents on the ground was 5.03%. Callosciurus pygerythrus was captured two times, eight times with Niviventor confucianu and six times with Rattus tanezumi, the catch rate was 0.63%, 2.52% and 1.98% respectively. The removal rates of animals get top under bamboo forest according to post-dispersal experiment, thereinto, ants remove 54.5% and rodent remove 44.5%.4. The number of seedling under the bamboo forest was related to the distance from the mother tree forest. The nearer from the mother tree the higher amount of seedling appear to be. The number of seedling was 0.73±1.10trees/m~2 in mother tree forest and 0.09±0.35 trees/m~2 in bamboo forest. Seedling survival ratio was 0.37% in mother tree forest and 10.23% in bamboo forest. The micro-habitat in bamboo forest was fit for seed germination. Birds transported seeds to bamboo forest, and had an important effect on the regeneration of Chinese yew.