The role of stochasticity in microbial community assembly

Most studies on microbial community dynamics focus on the deterministic drivers; that is, niche-based changes in community composition that can be explained by environmental factors. Additional unexplained variance can be attributed to unmeasured factors, or to stochastic processes, like demographic drift or priority effects. Although these processes are difficult to measure, null model approaches can help to reveal the relative roles of starting abundance, random interactions, and demographic drift in patterns of microbial community composition and function.