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 =
(n·nmx) /
(1+(n\(-\)nax)·nmx).
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. |