FIGURE 4.

Null deviation values from soil bacterial communities sampled along a 5-year chronosequence of tree mortality from bark beetle infestations. Null deviation values close to zero occur when the species (OTU) composition of communities being compared deviates less from random assortments suggesting stochastic processes are important influences structuring the community, larger values (negative or positive) indicate increasing deviation from random and suggest an influence of deterministic processes, possibly due to niche associations.