Facilitation

One model of ecological succession is facilitation. This mechanism takes place when a large disturbance has taken place in an environment rendering it useless to the organisms who once called it home. A pioneer species able to survive in this environment gains a foothold and begins to transform its surroundings by simply existing. The type of change it may produce will likely be in favor of its own species while simultaneously making the habitat not suitable for other species. After some time this initial species has become a prominent figure in the budding ecosystem, however, the modifications to the environment have made it ideal for other species. With their upcoming, the pioneer species population may be reduced in size until there is little to none left. The dominant species could not have lived in this environment if it weren't for the pioneer species. For this reason, the model was named 'facilitation, as one pioneer species facilitated the means by which another organism can come up.