Measuring specialization in species interaction networks

BMC Ecology

Table 1 Elements in a species association matrix. Interaction frequencies (a_ij) between c animal and r plant species and their respective totals (rows:A_i, columns: A_j, total elements: m).

	Animal sp.1	sp. 2	...	sp. c	Total
Plant sp. 1	a ₁₁	a ₁₂	...	a_1c	$A_{i = 1} = \sum_{j = 1}^{c} a_{1 j}$
sp. 2	a₂₁	a ₂₂	...	a_2c	$A_{i = 2} = \sum_{j = 1}^{c} a_{2 j}$
...	...	...	...	...	...
sp. r	a _{r 1}	a _{r 2}	...	a_rc	$A_{i = r} = \sum_{j = 1}^{c} a_{r j}$
Total	$A_{j = 1} = \sum_{i = 1}^{r} a_{i 1}$	$A_{j = 2} = \sum_{i = 1}^{r} a_{i 2}$	...	$A_{j = c} = \sum_{i = 1}^{r} a_{i c}$	$m = \sum_{i = 1}^{r} \sum_{j = 1}^{c} a_{i j}$

ISSN: 1472-6785