[Dominant species population structure and dynamics of natural secondary forest in Mulan-weichang, China]

To explicate the structure and dynamics of dominant tree populations of the natural se-condary forest in Mulanweichang, the canopy stratum composition, diameter class structure, static life table, survival curve, mortality curve, survival function and the time series prediction were studied. The results showed that there were 9 populations in canopy stratum, with Acer mono, Quercus mongolica, Tilia mandshurica and Betula platyphylla as the dominant populations. The survival curve of A. mono and T. mandshurica populations approximately belonged to Deevey-2 type, while that of Q. mongolica population and B. platyphylla population belonged to Deevey-3 type and Deevey-2 type, respectively. With the increase of diameter class, the mortality rate curves and the vanishing rate curves of all tree populations changed similarly. The maximum mortality rate and va-nishing rate of A. mono, Q. mongolica and T. mandshurica populations appeared in 4,1and1diameter class, respectively. B. platyphylla changed little over all diameter classes. The 4 survival functions showed that A. mono, Q. mongolica and T. mandshurica populations declined at early stage, but became relatively stable at intermediate and late stages. The B. platyphylla population had no obvious change. The time series prediction showed that the number of small-sized (1-2) individuals of B. platyphylla decreased gradually and tended to decline, while the populations of A. mono, Q. mongolica and T. mandshurica were fairly stable. We suspected that A. mono, Q. mongo-lica and T. mandshurica would finally dominate within this natural secondary forest.