Function to calculate the variance in size ratios
between adjacent, ordered species. If there is a tendency towards a
constant size ratio between adjacent species, this
variance will be relatively small. Alternatively, if some adjacent species
are close in size, but others are very distant, this variance will be
large. Small variances might be indicative of assemblages in which
there is a competitively-based limit to similarity.
Usage
var_ratio(m = runif(20))
Arguments
m
a vector of non-negative trait measures, one for each species
Value
Returns the variance of the size ratios between adjacent, ordered values.
References
Poole, R.W. and B.J. Rathcke. 1979. Regularity, randomness,
and aggregation in flowering phenologies. Science 203:470-471.
Simberloff, D. and W.J. Boecklen. 1981. Santa Rosalia reconsidered: size
ratios and competition. Evolution 35: 1206-1228.