So here we have an example problem that says to identify whether each of the following scenarios are examples of primary succession, which we'll abbreviate with the letters "PS", secondary succession, which we'll abbreviate with the letters "SS", a climax community, which we'll abbreviate with the letter "CC", or none of the above, which we'll abbreviate with the letter "X".

Now the first scenario says that after a severe landslide washes away all the soil in a forest, new species colonize the area. Since all of the soil is being washed away and initially there's no soil for the new species to colonize the area, this is what makes this primary succession. So we can put "PS" here for that.

Now the next one says an apex predator population in a river community declines due to a new disease. This one doesn't provide enough information to distinguish if soil is being impacted, and so we can't really determine whether primary or secondary succession is occurring here. Since this disease seems to be only impacting a single species within the community, which we would expect to have multiple different species, and there's no reason to assume that this predator couldn't recover back to its original state after the few individuals die from the disease. With not enough information to conclusively determine that this predator is part of a climax community that has reached its final stage and is in its most stable state, the best option is to classify it as none of the above, with an "X" here.

So we'll go ahead and do that. Now the next one says an ocean community has been stable for many years but still experiences occasional disturbances. The stability of this community indicates that this is a climax community. So we'll put "CC" here for that. Recall that the climax community is somewhat of the final and most stable stage of ecological succession where ecological succession is still occurring but at a significantly reduced rate.

Now the next one here says a volcanic eruption underwater creates a new oceanic island, which takes years for plants to colonize. Because a brand new oceanic island is being created and initially there will be no soil, this makes this primary succession. So we can put "PS" here for that.

Last but not least, the final scenario says a big wildfire kills virtually an entire community, but the soil is left intact allowing for new plant species to grow. Since the soil is left intact here, this makes this secondary succession. So we can put "SS" here for that.

This concludes this example problem, and I'll see you all in our next video.