3.4. Indexes of aggregation1. Coefficient of dispersion:
2. Mean crowding (Lloyd 1967) is equal to the mean number of "neighbors" in the same quad:
It means that the mean number of "neighbors" is = 4.25.
Note: mean crowding has biological sense only if the size of each quad corresponds to "interaction distance" among individuals.
Consider probability distribution p(i) = the proportion of samples with i individuals. Then:
For a random (poisson) distribution, CD=1, and thus, = m.
3. Lloyd (1967) suggested a "patchiness" index: /m, which is 1 for a random distribution, > 1 for aggregated distributions, and <1 for regular distributions. However it does not make more sense than CD.