Collective effects in the population growth of microbials

Abstract

We investigate the population growth of microbial species. While traditional approaches rely on the logistic equation, assuming the same growth type for all the community members, we show that the stochasticθ-logistic model (SθLM) for microbial ecosystems captures the diversity of growth patterns through a single parameter,θ. The estimation of this parameter from empirical data unveils a non-trivial distribution across taxa, indicating that population increasing is strictly species-dependent. Remarkably, the logistic scenario is not necessarily the most likely one, and sublinear growth is statistically ruled out. In addition to improving our understanding of how microbial abundance evolves over time, these results engage the field as a whole. From a macroecological perspective, this suggests that the abundance fluctuation distribution follows a generalized pattern, with the Gamma distribution discussed in previous literature being just a special case. Significantly, it contributes to the long-standing stability-diversity debate in the context of microbial ecosystems by discarding recent solutions involving sublinear growth.