Tx—The sum of average life of all individuals, Tx=Σ Lx
ex— Average life expectance ex=Tx/nx
Lx— The sum of average life of this age , Lx=(nx+nx+1)/2
藤壶的生命表
Survivorship data are often shown as a survivorship curve for a particular population; a graph showing the proportion of survivors on a logarithmic scale through each phase of life.
1.4 38
0.082
35
1
0
0
0
0
0.5 35
3.555
Dynamic-composite life table
Same as dynamic life table, but the age is different, here the age is a group marked at one time, actually age maybe different.
Life table analysis
1. Survivorship curves（存活曲线）
A curve showing the number of individuals which survive per thousand of population through each phase of life, often use a log scale for the numbers of individuals.
Dynamic life tables
Numerical data was obtained by observing the
whole dynamic life processes of a population
born at one time. 同生群生命表
Cohort: a group of individuals born at the same time.
Diagrammatic life table
Diagrammatic life table
Begon和Mortimer在1976年专为高等植物设计的一种图解生命表
F
成熟植株Nt 时间：t
种子（ N Nt × F× g）
p
存
活
率
e
成熟植株Nt+1 时间：t+1
Nt+1 =（ Nt × F× g ×e ）+(Nt ×p)
Dynamic life tables
Cohort life table
年龄级 (每龄3个
月)
x
早熟禾的同生群生命表
存活数 （每一季
的）
ax
存活数 (标准化)
lx
死亡数 (标准化)
dx
死亡率 qx
亏损度
Kx
lg ax-
lg ax+1
该龄级的 单株平均 种子数
Bx
0
843
1000
143
0.143
0.067
10
8
0
0
—
—
Static life table
Numerical data was obtained by investing age structure of population at one time.
Time specific life table
云杉种群静态生命表
x
lx
dx
qx
Lx
Tx
ex
ax
kx
1
1000 997 997 501 506 0.5 67424 5.954
5
3
2
714 2
5
2.0 175
1.253
10
1
0
60
1
3
4.6 50
0.062
15
1
0
64
1
3
3.9 47
0.066
20
1
0
63
1
2
3.1 44
0.071
25
1
0
73
1
1
2.3 41
0.076
30
1
0
79
1
1
Life expectancy
Life expectancy--the average additional time still left to individuals alive at a particular age x
ex=Tx/nx
Life table types
Dynamic life tables（动态生命表）, age-specific life table(特 定年龄生命表 ), Cohort life table(同生群生命表) ,horizontal life table(水平生命表)
0
1
722
857
232
0.271
0.137
300
2
527
625
250
0.400
0.222
620
3
316
375
204
0.544
0.342
430
4
144
171
107
0.626
0.426
210
5
54
64
46.2
0.722
0.556
60
6
15
17.5
14.24
0.800
0.699
30
7
3
3.56
3.56
1.000
There are three generalized patterns of age-specific survivorship depending on whether the probability of dying is highest later in life (Type I), constant through life (Type II) or highest for young stages (Type III).
Static life table（静态生命表） time-specific life table(特定时 间生命表 ),vertical life table(垂直生命表)
dynamic-composite life table(动态混合生命表） diagrammatic life table (图解式生命表 )
x：年龄级 nx：在x龄级开始时的存活个体数 lx : 在x龄级开始时的标准化的存活个体数 dx : 从x到x+1期标准化的死亡个体数 qx : 从x到x+1期的死亡数 ex : x期开始时的平均期望寿命或平均余年 Lx : 从x到x+1龄期的平均存活个体数 Tx : 龄期x及其以上各年龄级的个体存活总年数
3生命表
x — Age
nx— Number alive at start of age X dx— Number of death during x to x+1 qx— Death rate during x to x+1, qx=dx/nx lx— Proportion alive at start of x, lx =nx/n1