%0 Journal Article
%A Ya-Ping HE
%A Shi-Min FEI
%A Jun-Ming JIANG
%A Xiu-Ming CHEN
%A Xu-Dong ZHANG
%A Fei HE
%T INFLUENCES OF SUBSTITUTING SIZE VARIABLES FOR AGE ON POPULATION SURVIVAL ANALYSIS: A CASE STUDY OF *PINUS TABULAEFORMIS* AND *P. ARMANDII* IN QINLING MOUNTAIN, CHINA
%D 2008
%R 10.3773/j.issn.1005-264x.2008.02.024
%J Chinese Journal of Plant Ecology
%P 448-455
%V 32
%N 2
%X *Aims* Our objectives were to 1) explore the feasibility of using individual height and basal diameter as substitutes for age, and 2) determine the influence of using these parameters on survival curve analysis for *Pinus armandii* and *P. tabulaeformis* populations in an area damaged by water disaster in the northern Qinling Mountain.

*Methods* We investigated two dominant species, *P. tabulaeformis* and *P. armandii*, which had regenerated after damage by water disaster 17 years earlier. We measured height, basal diameter and age of two species in 6 plots (total plot area was 11 900 m ^{2}). We determined age by counting number of whorls of branches.

*Important findings* It was infeasible to use basal diameter and tree height in place of age for *P. armandii* because the relationship to age was an exponential function for both parameters; therefore, we used logarithmic values for basal diameter and tree height. In contrast, the functions were linear for *P. tabulaeformis*. The survival curves were all linear type with no type differences between base diameter, tree height and factual age. Our study indicates that it is feasible to use basal diameter and tree height as indices for factual age when the relationships of basal diameter and tree height to age are linear. Investigation of relations of age and size and their influential factors is important for the analysis of plant population demography.

%U https://www.plant-ecology.com/EN/10.3773/j.issn.1005-264x.2008.02.024