Suppose a plot of forest is cleared of trees in anticipation...

Name: Problem 9, Chapter 19: Biology: The Essentials
Uploaded: 2020-10-30T16:09:25-08:00
Duration: 4 min 20 s
Channel: Hiram Johnson
Description: Suppose a plot of forest is cleared of trees in anticipation of a new shopping mall. However, after the bulldozers are gone, the company runs out of money, and the land sits undisturbed for many years. Describe the events that may occur in the years following the damage to the forest. What are these community changes called?

Suppose a plot of forest is cleared of trees in anticipation of a new shopping mall. However, after the bulldozers are gone, the company runs out of money, and the land sits undisturbed for many years. Describe the events that may occur in the years following the damage to the forest. What are these community changes called?

Key Concepts

Ecological Succession

Ecological succession is a process of gradual change and development in an ecosystem after a disturbance. It involves the sequential appearance and replacement of species over time, which eventually leads to a climax community that has reached a relatively stable state. This process highlights the dynamic nature of ecosystems as they respond to both natural and human-induced changes.

Secondary Succession

Secondary succession refers to the ecological recovery process that occurs in an area where an existing community has been disturbed or partially removed but where the soil and some organisms remain intact. This type of succession typically follows events that alter the ecosystem, such as clearing or fire, and it tends to progress more rapidly than primary succession because of the residual organic matter and seed bank present.

Disturbance

Disturbance in an ecological context is any event that disrupts the structure, composition, or functioning of an ecosystem. It may be caused by natural events like fires or storms or by human activities such as deforestation and construction. Disturbances act as catalysts for ecological succession and community reassembly, ultimately influencing biodiversity and ecosystem resilience.

Community Dynamics

Community dynamics refer to the changes and interactions among species within an ecosystem over time. This concept encompasses the processes of species colonization, competition, and extinction, which together shape the structure and function of ecological communities. Understanding community dynamics is essential for studying ecological succession and the overall health of ecosystems.

Transcript

00:01 So basically this question is asking us, what happens in a biological community over time after an event, as described here, basically a section of forest being cleared to make room for development? what happens if that space that was cleared is then abandoned and left its own devices? now, this is basically a fantastic example of what we call secondary.

00:34 Succession.

00:37 Now, brief recap, secondary succession, what succession is, ecological succession, is basically how the species structure of an ecological community changes over time.

00:48 Secondary succession takes place when the community already existed, the ecological community, i mean, small scale disturbance, nothing like a, you know, volcano exploding or a meteor hitting, but small -scale disturbance, not tree -cutting, forest clearing takes place, but not, but the succession does not take place from scratch because the materials needed for life to be sustained are still there in the soil.

01:52 So to illustrate this, let's draw this kind of ecological timeline.

01:59 Sorry, it's not too straight.

02:00 I'm not too good on straight lines on this whack -home.

02:04 Let's see.

02:06 So 0, 1, 2, and 3.

02:13 So for number 0, this is right after the clearing.

02:18 There's nothing here but dirt.

02:22 All right.

02:24 This second stage, however, in this first stage of secondary succession, technically, is what happens when small kind of annual grasses and flowers begin to kind of colonize the space left behind by the cleared trees.

02:48 Basically, these guys are called pioneer plants.

02:58 So this first stage, pioneer plants.

03:00 Plants move in and start to recultivate the soil and prepare it for bigger plants...

Please give Ace some feedback