Characteristics of the Age Structure and Dynamics of Malus sieversii Population
The wild apple forest of Malus sieversii endemic to Toli and Emin Counties,Xinjiang,were surveyed by sampling method of typical sampling methods.Based on the survival analysis,and with space (diameter at breast height,DBH) instead of time (age of tree),we constructed the age structure and static life tables,and drew the curves of survival.With the time series models,the forecast development trend of the population was also predicted.Results showed that:(1) The individual number of the middle level(20 ＜DBH≤30 cm) in M.sieversii population was relatively stable.While the individual numbers of saplings (DBH≤15 cm) in M.sieversii population was many,but was unstable.The big(30＜DBH≤40 cm) and old (DBH＞40 cm) trees in M.sieversii population were significantly reduced as a result of physiological aging,interspecific competition and environmental factors.(2) The estimated survival curve roughly showed the form of Deevey-Ⅰ.Dynamic performance prophase and mid-term slow growth,relatively stable,later period recession.(3) Time sequence prediction models for different populations after 10,20 and 30 years indicated that the number of old individuals would increase and that young individuals would decrease,both 2 populations showed apparently aging tendency.
Toli CountyEmin CountyMalus sieversiiage structuredynamics
NETL
NSTL
万方数据
维普
