Captioning is on! To turn off, click the CC button at bottom right. Follow the amoebas on Twitter (@amoebasisters) and Facebook! We love Disney movies and we have to say---Lion King is one of our favorites. And like a lot of Disney movies, it has a happy ending. We’re not going to give spoilers just in case you are one of the few people left in the world that hasn’t seen the Lion King--- go see it ---but at the end of Lion King, you start to see all this life growing back. The sun comes out and all these plants start growing. Happy music plays. The animals that had disappeared start to come back! I never really understood where they went but…they come back! And being a biology teacher, everything is destined to have a biology reference. So here’s what it reminds me of: ecological succession. Although, the movie is kind of like ultra fast impossible ecological succession. It’s not that fast in real life. Most dictionaries define succession as the following of one person or thing after another in an order or sequence. Well ecological succession is that but in terms of ecology. Ecological succession is a process---over time--- of organisms in an ecological community. What’s a community? Well in ecology, we have different levels of organization. We have a living organism as our first level. A hippo for example. Then we have a population, which is when you have the same species of an organism in a given area. For example, a population of hippos. Same species so that’s one population. Then we have a community. A community includes many populations living together in a particular area. So now we have hippos, lions, giraffes, and don’t forget plants because those are populations too. Trees and…shrubs. All of this together is a community. That’s where we are going to focus for succession. There are more levels beyond the community level, but this is our focus right now. There are two types of succession that we will talk about. One is called primary succession. In primary succession, the area this is happening in is brand new---well in the sense that you’re usually talking about an area that doesn’t have any soil. So this usually has to be a special circumstance. An example could be a volcano lava flow that now has left this new area with no soil present. Usually you have a pioneer species, which is a name for the species that colonize first. It sounds exciting…pioneer species in primary succession can be organisms like lichen. Who doesn’t like lichen? Ha…if you are unsure about what lichen is…google it! It’s very likely you’ve seen lichen before. Moss is another potential pioneer. After pioneer species colonize the area, they slowly break down rock into smaller, more plant friendly substrate---and over time, contributing more organic matter in newly formed soil which will support plants. Small vascular plants like grasses and plants that you might consider “weeds” can come in. Shrubs can follow. Then trees. Animals can move into the area. How long this takes can vary…but it’s often hundreds of years before you get a climax community going. And if you’re wondering---why this sequence? Why doesn’t it just stop with grass? Well, keep in mind that as other plants come in…bigger plants…you are going to see more competition for space and resources. Think about how it would be by the time trees come in! Trees are going to block some of the light that small plants underneath them may be dependent on. As new larger plant species come in, this competition brings about a new order. And if you are wondering---where did these plants even come from? Well there are so many ways that seeds can be dispersed---wind, water, animals. Check out our plant reproduction video for more information about how these plants could have actually come into the area. Now for secondary succession. Similar to primary succession, it follows a typical ecological sequence. With secondary succession---I like to think second---because it’s like a “coming back again a second time.” What I mean by that is usually you’re talking about an area that once had plants and animals and a full ecological community going on. But then we had a disturbance…an ecological disturbance…like a forest fire, a flood, a tornado. Actually it doesn’t have to be a natural disaster---human activity can be involved with secondary succession. Regardless of the type of event, in secondary succession, the soil is still there and that’s kind of the big key point here, because your pioneer species will actually have soil to grow in. That means your pioneer species in secondary succession will often be small plants as there is already soil present. Secondary succession will then follow a similar sequence to primary succession after that point. Since secondary succession involves soil already being available, it is more likely to be a faster process than primary succession. An important thing to remember about ecological succession is that it really shows the diversity of organisms---the sequence we had talked about--- in an ecological community over a period of time. Usually a long period of time. Ecological succession, over time, can support an ecological community that continues to increase in biodiversity. And, biodiversity is a beautiful thing. That’s it for the amoeba sisters and we remind you to stay curious!