Breath of Clarity

Ecology Discussion #4: A

Comment #1 as a response to Amanda Ruffini’s Succession Infographic:

Hi Amanda,

Thanks for distinguishing primary succession from secondary succession. It is interesting secondary succession does not include the entire lichens/mosses block. The picture you selected is a great way to communicate how the progress made in primary succession impact the secondary succession’s process.

The graphic also shows the progression from plant –> shrub –> tree. It focuses on showing the increase in plant growth as opposed to the increase in complexity of plant species. It was helpful for me to see yours as mine focused on the latter of the two. I wonder how a picture integrating animals into the equation would alter the photo. It would definitely depend on the types of animals chosen as they all do not feed on the same types of plants.

In terms of the progress you outlined, you made a great point in saying, at the end of the disturbance, soil is intact and resource rich. It is a crucial element to allowing the succession to continue. I also appreciate how you noted competition happening in stage 2, as opposed to only in stage 3. It acknowledges not everything dies during the stage 1 disturbance phase. Lastly, good job in saying shade tolerant vegetation remains after trees mature. The changing sun exposure definitely is a major factor in determining the results of competition. Question- can you signify the word “resemble” in the final stage? To what degree is the final stage similar to pre-disturbance?

Response by Amanda Ruffini:


From my understanding, lichen/moss is part of primary succession as the soil is undeveloped and is not nutrient-rich like the soil in secondary succession. This is the only type of vegetation then that can really successfully grow there. Since the image showed a disturbance, I wanted to be clear that this will result in secondary succession, not primary. I also would have been interested to see succession in terms of wildlife as well. I would imagine that it starts off with smaller creatures and by the time it becomes a mature forest once again, it can house bigger and more complex species, as it provides more resources, a larger habitat, and good protection.

And thanks for the question! What I meant by “resemble” is that the new climax community, after the disturbance, will not 100% match the previous climax community. It will instead resemble it but not be it. That is because disturbances can change the look of the community, so it will never go back to what it was exactly. Maybe resemble was not a good word choice for this.

Comment by Professor Fenton Kay:

Very good point regarding the appearance and composition of “restored” systems, Amanda. You are correct, the systems nearly never look just like they did before the disturbance. Some of the species take a long time to recover. Others just don’t come back for a variety of reasons. In fact, that is one of the things that restoration ecologists hope for in controlling invasives.



Comment #2 as a response to Michael Muehlberger’s Succession Infographic:

Hi Michael,

Awesome infographic! I noticed all of us have portrayed succession in four stages. I wonder whether there is any other consistency in all instances of succession aside from the steps we are all noting. It is interesting the same four stages occur across various forest areas far in distance from one another. I am also amazed by the ability of forests to be resilient following various types of disturbances. I also appreciate the way you listed the three levels of species under stages 2-4. It helped me understand the difference between the pioneer community and intermediate community. It also helps communicate how the diverse plant and animal species feed on the original pioneer community. I also notice a general trend of all the graphics emphasizing stability at the climax.

Some questions: Is the pioneer community always only plants? Is your graphic depicting the large trees in the climax community as the same types of trees that were small in the intermediate community? Do the actual plant and animal species types grow in size from pioneer to climax or does the ecosystem community grow in complexity?