In inhibition model of succession:
The inhibition model gives early occupants a negative effect on later colonists. Once pioneers establish, they monopolize space, light, nutrients, or attachment sites, or they release inhibitory chemicals, thereby preventing other species from recruiting successfully. Succession proceeds mainly when residents die, are damaged, or are removed by consumers or disturbance, creating openings that another species can occupy. The first colonist need not prepare the site for its successor and may even be a long-lived species, so the sequence depends strongly on arrival order and priority effects. In
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20