Welcome to Chinese Journal of Ecology! Today is Share:

cje

• Articles • Previous Articles     Next Articles

Growth dynamics and quantitative population characteristics of young trees in coastal Pinus thunbergii windbreak forest in northern Shandong Peninsula.

HAN Guang-xuan;ZHANG Zhi-dong;WANG Guang-mei;MAO Pei-li;LIU Su-jing;XUE Qin-zhao   

  1. Yantai Institute of Coastal Zone Research for Sustainable Development, Chinese Academy of Sciences, Yantai 264003, Shandong, China
  • Received:2008-10-14 Revised:1900-01-01 Online:2009-06-10 Published:2009-06-10

Abstract: Coastal Pinus thunbergii windbreak forest is a typical ecosystem in th e coastal zone of northern Shandong Peninsula, and plays a key role in regional ecological security. To study the natural regeneration pattern of the forest, th e growth dynamics and quantitative characteristics of regenerated P. thunbergi i trees were investigated in three plots. The tree ages were determined by cou nting tree branches, and the growth dynamics, age structure, and spatial distrib ution of regenerated young trees were studied by the method of spatial series su bstituting for time series. Based on the life table of population and the theory of survival analysis, the life tables of regenerated young P. thunbergii tr ees were established, and the survivorship curves were drawn with field data. Th e results showed that in the three plots, the height and basal diameter growth o f regenerated young P. thunbergii trees had exponential, linear, and quadrat ic functional relations with age, and the age structure was of spindle, discrete , and pyramid types, respectively. Most of the regenerated young trees were dist ributed at 03〖KG-*2〗-〖KG-*7〗12 m from their nearest standing trees, and the individuals of the young trees decreased near to or far from the nearest sta nding trees. In plots Ⅰ and Ⅲ, the expected average life of regenerated young P. thunbergii trees had a decreasing trend with their increasing age, and th e survival number of the population also decreased with increasing population ag e. The survivorship curves of regenerated young P. thunbergii trees in the t wo plots approximated to the type of Deevey Ⅱ, indicating that the young P. t hunbergii populations in the plots were at stable development stage. The popul ation structure of regenerated young P. thunbergii trees in plot Ⅱ was less er integral, suggesting that the population was of declining type, being related to human disturbance, slope and other environmental factors.

Key words: Daphnia magna, 1,8-dihydroxyanthraquinone, Toxicity, Toxicology