Forests provide a wide range of services to humans and create critical habitat for countless species. Tree species composition and diversity, key attributes of forest health and identity, are influenced by both disturbance and conspecific negative density dependence (CNDD). These factors have been thoroughly researched in isolation, but much less is known about how they interact. We present results of a simulation model constructed to investigate the interactions of variable CNDD strengths and disturbance types. We found that while CNDD consistently increased diversity, the magnitude of this effect was heavily influenced by the disturbance regime. The difference between weak and strong CNDD was most pronounced with understory disturbance, and the greatest diversity overall was achieved when strong CNDD was paired with understory disturbance. Empirical studies of CNDD have yielded widely divergent results. Our study suggests a comprehensive understanding of forest ecosystems may require simultaneous consideration of both disturbance and CNDD
