Data and code from: Network theory predicts ecosystem robustness across environmental conditions

Network theory quantifies how changes in species richness, S, lead to
changes in the number of interactions (or links) between species, L.
Networks with a steep relationship between L and S have a high number of
links per species, making the network resistant to collapse and therefore
more robust. However, changes in S often coincide with environmental
shifts, which can lead to impacts on L that are not expected from network
theory. In this paper, we constructed relationships between L and S for 18
ecosystems using 1081 observations collected across 420 environmental
conditions. We found that environmental noise (unspecified spatiotemporal
variation) and environmental gradients (directional environmental change)
commonly affected ecological network size (S and L), community
composition, and also induced network rewiring, which means that species
changed interaction partners as the environment changed. Yet, we found the
log(L) ~ log(S) relationship to be remarkably constant across
environmental conditions. Specifically, the slope of this relationship
remained constant across conditions, implying consistency in how species
loss proportionally affects L. Our results therefore show that network
theory predicts ecosystem robustness across environmental conditions.
These results suggest generality to how environmental drivers operate at
the level of ecological networks, which is encouraging for conservation.