Sample Life History Table: iteroparous
species with overlapping generations
|
Age (x) |
Number surviving
to each age class |
Probability of Survival (lx) |
Mortality to
each age class |
Probability of
dying by next age class (dx) |
Fecundity (bx) |
lxbx
|
lxbxx |
|
0 |
100 |
1.0 |
55 |
.55 |
0 |
0 |
0 |
|
1 |
45 |
.45 |
30 |
.67 |
2.0 |
.9 |
.9 |
|
2 |
15 |
.15 |
10 |
.67 |
2.5 |
.375 |
.75 |
|
3 |
5 |
.05 |
5 |
1.0 |
2.5 |
.125 |
.375 |
|
4 |
0 |
0 |
- |
- |
- |
0 |
0 |
Reproductive value (Ro) = å lxbx = 0 + .9 + .375 + .125 + 0 = 1.4
Generation Time (T) = å lxbxx / å lxbx = 2.025 / 1.4 = 1.45
Growth Rate (r) = lnRo / T = ln 1.4 / 1.45 = .336 / 1.45 = .232