Spatial And Temporal Dynamics Of Seed Dispersal Of Pinus Koraiensis, Corylus Heterophylla And Corylus Mandshurica In Xiaoxing'an Mountains

To study seed dispersal effectiveness of Pinus koraiensis, Corylus heterophylla, Corylus mandshurica by small rodents, we carried out studies in Xiaoxing'an mountain areas, Heilongjiang Province in 2008, 2009 and 2010. Results are as follows:(1) Seed removal rates is mainly affected by seed species and seed traits,the rates of three seeds removal did not differ significantly among years.(2) The proportions of seeds eaten in situ, cached seeds and missing seeds were different among years, indicating the annual effects on seed fates.(3) Dispersal distances of Pinus koraiensis and Corylus mandshurica did not variy among years, however, dispersal distance differed in seeds of Corylus heterophylla.(4) Mast seeding of Corylus mandshurica showed negative effects on seed dispersal of Corylus heterophylla, but not Corylus mandshurica and Pinus koraiensis.(5) Mast seeding of Corylus mandshurica significantly increased the proportion of cached seeds of Corylus mandshurica and Pinus koraiensis. Mast seeding of Corylus mandshurica significantly increased its own seed dispersal distances, reduced those of Corylus heterophylla. No effect was detected on Pinus koraiensis.(6) Seed traits and seed species rather than habitat heterogeneity influenced seed dispersal and removal. However, seed fates were significantly different among habitats. our studies also indicated that seed hull thickness was one of the crucial factors influencing seed dispersal.(7) Seed dispersal distances were greatly influenced by habitat heterogeneity, surface conditions seemed to be an important factor determining seed dispersal.