Study Rain And Seed Dispersal Of South Slope Fagaceae Seeds

Seed rain and seed dispersal are two key stages during the process of natural regeneration of forest plant populations. The mature seeds falling from the trees is described as "seed rain". Plant seeds are important food resource of forest rodents, after the mature seeds fall down, part of the seeds will be eaten while the other part will be hoarded to meet future food shortages. This part of the seeds will germinate successfully and achieve plant renewal if they are stored in suitable conditions and escaped form the predation by hoarders. Therefore, forest rodents play an essential role in plant seed dispersal and forest regeneration.At present, although there are many domestic and foreign research on seed rain and seed dispersal, the current research in this area in the country is very uneven, and research about seed rain and dispersal behaviors of forest rodents in Qinling Mountains have rarely been reported. Based on the composition and dynamics of seed rain and the analysis of studies on seed dispersal by forest rodents, we select Foping National Nature Reserve which located in the subtropical and warm temperate transition zone of Qinling Mountains as the study site, using Fagaceae seeds and rodents which distributed sympatrically in the study region as the study object, to carry out the study of seed rain and seed dispersal.The main conclusions of this article are as follows:1. Studying the seed rian on the composition and dynamics of Castanea mollissima、Quercus aliena、Q. variabilis and Q. glandulifera seeds. The results showed that:The seed rain of four Facaceae species started from mid-August, and finished at the end of November. The peak in the number of seeds appeared in late September to mid October, and the fall peak of each seed rain category of Castanea mollissima was earlier than other three species. Whether in2011or2012, there were significant differences in each seed rain category dynamics among Q. variabilis, Q. aliena and Q. glandulifera, but there was no significant difference between each seed rain category dynamics in C. mollissima. There were significant differences in seed rain dynamics of four species within a year, and the seed rain density of each category was higher in2011 than in2012(except Q. variabilis). This result conjectured that2011may be the relatively mast seeding year.2. Studying the seed dispersal of Castanea mollissima.The results showed that the forest rodents play an important role for seed dispersal. In2011, the number of seeds peaked at day17,10%seeds stored and survived at the end of the experiment. In2012, although the seed hoard peaked earlier,6%seeds stored and survived at the end. There were significant differences of the dispersal process of Castanea mollissima between the two years, the results may have close connection with mast seeding phenomenon.3. Studying the seed dispersal of Q. aliena. The results showed that in2011, the dynamic of seed fate(remained in situ, eaten in situ, eaten after removal, hoarded) was different significantly. The seeds were dispersal slowly, were eaten and hoarded at very low proportion and still nearly90%of the seed retained in situ until the end of the experiment. In2012, the seeds were dispersed relatively fast, there had no seed after27days, the proportion of eaten and dispersal seeds are higher and still12%of the seeds survived at the end of the experiment.4. Studying the seed dispersal of three Fagaceae species. The results showed that there were significant differences in eating and hoarding strategy, the rodents like eating Q. aliena and Q. glandulifera because of its smaller size and lower nutrient content, it prefer hoarding larger, higher nutrient content of Q. variabilis. Therefore, the seed storage strategies of rodents have a very close relationship with seed size, nutrient content and seed characteristics.