Distinct strategies of soil bacterial generalists and specialists in temperate deciduous broad-leaved forests

Based on global biotic homogenization, habitat generalists and specialists play an important role in maintaining the stability of ecosystems. However, limited information is available about the assembly processes and co-occurrence patterns of soil bacterial habitat specialists and generalists in forest ecosystems, particularly their response mechanisms to environmental factors. In this study, high-throughput sequencing technology was used to investigate the role of the ecological assemblage processes of soil bacterial habitat specialists and generalists and their role in maintaining the stability of the symbiotic network in temperate deciduous broad-leaved forests (China). The results showed that compared with specialists, the diversity of bacterial habitat generalists was lower, but their distribution ranges and environmental niche breadth were wider. Results from the null and neutral models indicate that, compared to deterministic processes, the community assembly of habitat generalists and specialists is more strongly influenced by stochastic processes, with generalists exhibiting a higher degree of stochasticity than specialists. Network analysis results showed that habitat specialists played a greater role in maintaining the stability of the bacterial co-occurrence network than the generalists. In addition, bacterial habitat specialists were more likely to be affected by light and spatial feature vectors than generalists. These findings provide a novel perspective for understanding the assembly processes and diversity maintenance mechanisms of the forest soil bacterial community.

Limited information is available about bacterial specialists and generalists in forests. Generalists were more affected by stochastic processes than specialists. Specialists played a more important role in network stability than generalists. Light and spatial vectors had stronger effects on specialists than generalists.