Succession

(AHL portion of IB Topic D4.2)

Essential Idea(s): Ecological succession is the gradual change in species composition and ecosystem structure over time, as organisms modify their environment and create conditions that allow new communities to establish, culminating in a relatively stable climax system.

Unit Length: 1 AHL Lesson

  Guiding Questions

◊ What features of ecosystems allow stability over unlimited time periods?

◊ What changes caused by humans threaten the stability of ecosystems?

Materials:

Self-Teaching Slides (AHL) Quizlet Vocab Set (for all of D4.2)
Notes Template (AHL)

 

IB Statement(s) and Objective(s)

 

Additional Higher Level Topics

D4.2.12: Ecological succession and its causes

  • Define ecological succession
  • State an example of ecological succession triggered by an abiotic factor
  • State an example of ecological succession triggered by a biotic factor

 

D4.2.13: Changes occurring during primary succession

  • Describe changes occurring during primary succession in a community, including: increases in size of plants, amount of primary production, species diversity, complexity of food webs and amount of nutrient cycling

 

D4.2.14: Cyclical succession in ecosystems

  • Define cyclical succession
  • Explain an example of cyclical succession in an ecosystem

 

D4.2.15: Climax communities and arrested succession

  • Define climax community and plagioclimax
  • Give an example of a plagioclimax community
Activities: ⓟ = podcast / ⍰ = inquiry 5 / ⓦ = Write it /  Ӕ = The academy  / Ⓡ = Read it

Old School Worksheet: Succession

Go here and complete this simple worksheet Q&A on ecological succession.  

ⓟ/ⓦ: How We Could Colonize Space: Jayne Poynter’s Story of Biosphere 2 (👫 max 3)

Imagine living for two years inside a sealed “mini-Earth,” where every breath of air, drop of water, and bite of food depends on a carefully balanced ecosystem — with no outside help. In this NPR clip on a project called Biosphere 2, one of the participants reflects on what the experiment revealed about sustainability, ecosystem stability, and unexpected feedback loops in closed systems. Watch the TED Talk and create a short podcast to discuss what Biosphere 2 can teach us about maintaining stable ecosystems on Earth. Here are a few guiding questions, if you need some:

  • Can Biosphere 2 be considered a large-scale mesocosm? Why is it useful as a model for studying ecosystem stability (D4.2.4)?
  • Did Biosphere 2 experience any tipping points where small changes led to major ecosystem shifts?
  • Were there organisms in Biosphere 2 that functioned like keystone species? How did their presence or absence affect stability?
  • What challenges in Biosphere 2 mirror sustainability issues in agriculture or natural ecosystems today (D4.2.7)?
  • How might ecological succession have unfolded inside Biosphere 2 if the experiment continued longer (D4.2.12–D4.2.15)?

…more forthcoming!