SI2: Flowering synchrony index of Augspurger (1983)

In flower: Tools for characterizing flowering traits

Description

It measures the extent of overlapping in the flowering periods among pairs of individuals in a population.

Usage

SI2(dd, pop, ind)

Arguments

dd	Flowering data.
pop	Research scale, such as Population, individual, inflorescence, single flowers.
ind	ID ofindividual or inflorescence.

Details

si=(1/(n-1))*(1/fi)sum(ej);(j=1:n)

Value

n	The number of individuals in the population.
fi	The number of days individual i was flowering.
ej	The number of days that individuals i and j are flowering synchronously, with j != i.
bij	Number of days on which at least one of them (j and/or i) is flowering.
si	Synchrony index,from 0 (total lack of synchrony) to 1 (perfect synchrony).

Note

SI2 has been criticized for its dependence on flowering duration because the factor 1/fi increases the level of synchrony when flowering duration decreases.

Author(s)

WANG,XIE

References

[1]Augspurger, C. K. (1983). Phenology, flowering synchrony and fruit set of six neotropical shrubs. Biotropica 15: 257~267.

See Also

nothing

Examples

a1=c(0,1,1,1,0,0,0)
a2=c(0,1,0,1,1,0,0)
a3=c(0,0,0,1,1,1,0)
a4=c(1,0,0,1,1,0,1)
a5=c(0,0,1,1,1,0,1)
a6=c(0,0,0,1,1,1,1)
pop=c("pop1","pop1","pop1","pop2","pop2","pop2")
ind=c(1,2,3,1,2,3)
dd=rbind(a1,a2,a3,a4,a5,a6)
colnames(dd)=c("D5/1","D5/2","D5/3","D5/4","D5/5","D5/6","D5/7")
C=SI2(dd,as.matrix(pop),as.matrix(ind))
C

Example output

[1] "pop1"
         si
1 0.5000000
2 0.6666667
3 0.5000000
[1] "pop2"
    si
1 0.75
2 0.75
3 0.75
     n  min       max      mean         sd
pop1 3 0.50 0.6666667 0.5555556 0.09622504
pop2 3 0.75 0.7500000 0.7500000 0.00000000

flower documentation built on May 1, 2019, 9:27 p.m.