Table 1.

Mean ± s.e. community structure measures for the control (c1–c4) and drought (d1–d4) treatments for connected species within the food web. See §2 for details. Paired t-tests were performed to test for significance of mean differences (d) from zero. Results for additional scenarios testing for indirect effects (see §2) are given in the electronic supplementary material, table S2.

	control webs	drought webs	d	t	p
pairwise links, tritrophic interactions and food chains
median link angle	−27.17 ± 0.24	−27.59 ± 0.24	0.42	3.52	0.039
mean link length	18.23 ± 0.18	18.62 ± 0.11	−0.40	−2.11	0.125
median Alower	−26.67 ± 0.40	−25.76 ± 1.02	−0.91	−1.04	0.375
median Aupper	−31.80 ± 1.09	−142.30 ± 9.67	110.5	10.46	0.002
log10 number of tritrophic chains	2.05 ± 0.20	1.29 ± 0.01	0.77	4.05	0.027
median Abetween	−8.99 ± 3.93	−116.53 ± 9.78	107.5	13.40	0.001
mean two-span	19.2 ± 0.19	18.05 ± 0.11	1.11	6.21	0.008
mean chain span	19.4 ± 0.17	18.7 ± 0.10	0.69	6.06	0.009
mean food chain link count	1.49 ± 0.17	1.09 ± 0.01	0.39	2.32	0.103
trophic level of apex predator (chain length)	2.53 ± 0.05	2.16 ± 0.04	0.37	7.64	0.005
community scaling and whole-network properties
allometric slope	−0.50 ± 0.006	−0.52 ± 0.002	0.017	3.71	0.034
community span	28.1 ± 0.17	27.7 ± 0.08	0.33	1.94	0.148
constraint space area (MN convex hull area)	60.23 ± 2.45	43.09 ± 1.86	17.14	4.76	0.018
S, the number of connected food web nodes	60 ± 1.3	46.5 ± 1.3	13.5	11.34	0.001
log10 L, number of links	2.48 ± 0.05	2.31 ± 0.04	0.17	3.20	0.050
C, directed connectance	0.08 ± 0.008	0.09 ± 0.008	−0.01	−0.87	0.448