Figure 3.

Interactions attenuated as richness increased

The shift in interactions between richness contexts varying by a richness of one for A) population level (presented as “ratio – 1”), and B) per-capita effects. All comparisons of an interaction were compared between richness contexts varying in richness by a single isolate. Each arrow on the plots represents an interaction observed in two separate richness contexts (e.g., 1=>2 and 2=>3 community members), with the tail of the arrow representing the value of the interaction in the lower richness context and the head of the arrow representing the value observed in the higher richness context (population level: n = 220, per-capita: n = 231). Arrows are colored by the initial direction and the shift in direction of an interaction. For ease of interpretation, interactions were ordered along the y axis by initial interaction strength. Some interactions were observed in multiple higher richness contexts and are thus presented as multiple arrows with tails aligned on the x axis. Labels display the shift in median interactions for initially positive and negative interactions, respectively, with p values summarizing the outcome of Wilcoxon signed-rank tests to determine if the shift in interaction value represented a significant change.