Why is the rapid reproduction of certain plant species in the community a signal of its gradual death?

Usually, when the limiting factor of any population disappears, it begins to multiply indefinitely. At the same time, the density of the population of the territory occurs, since the number of individuals increases, they do not have enough food and water resources. There are also outbreaks of various diseases, so the population density is high. As a result of the influence of all these factors, there is a sharp decrease in the population size. Therefore, with the rapid reproduction of any population, we can talk about its imminent sharp reduction or disappearance.