Coefficient Definition and calculation
x Age at the start of each age class. We assume xs are 1–7 for age classes 1–7.
n Interval length between age classes, which is assumed to be one in this study.
nNx Observed number of individuals alive in the middle of an age interval. nNx in the first age class was calculated by assuming a proportional relationship between the number of germinated seeds and species basal area (see Materials and Methods); nNx of the other age classes (2–7) are from field survey.
nNx* Estimate of nNx by smoothing (see Materials and Methods).
nDx Number of individuals died during the observational period: nDx = nNx*\(-\) nNx+n*. All individuals are assumed to be dead in the final age class.
nmx Age-specific mortality rate: nmx = nDx / nNx.
nax Average length of survival time in each age range, which is assumed to be 0.5.
nqx Probability of death from ages x to x+n: nqx = (nmx) / (1+(n\(-\)naxnmx). nqx of the last age class is assumed to be one.
npx Probability of survival from ages x to x+n: npx = 1\(-\) nqx.
lx Relative number of individuals entering the interval at age x. lx+n = lx*npx. The initial population size entering the smallest age class (l1) is assumed to be one in this study. Thus, lx can be interpreted as the probability of survival to age class x.
ndx Relative number of individuals died from ages x to x+n: ndx = lx\(-\)lx+1.