5.1 Ecosystems & Communities

Essential Biology: 5.1 Ecosystems and Communities


Energy Flows, Nutrients are Recycled:

Energy flow animation, from MHHE

Global Carbon Cycle tutorial, from Freeman

Nitrogen Cycle animations from Nodvin.net and from ClassZone.com

The Calcium Cycle, from Bill Duesing

Biogeochemical cycles, from Wikilabs

Here’s a neat time-lapse of flesh-eating beetles at London’s Natural History Museum doing some recycling of their own:

Energy flows… but nutrients recycle. We are made of organic molecules – nutrients. So why not truly go green?

For more on how saprotrophs such as fungi can be harnessed to solve pollutant problems, check out Paul Stamet’s talk: 6 ways mushrooms can save the world.


This content is closely linked to G2: Ecosystems and Biomes.

Here’s a nice timelapse showing the breakdown of food by bacteria, fungi and other organisms (nutrients being recyled):

Ecology is life, and life is complex relationships. Here’s an overly-brief TED Talk on how to see the simple issues in complex situations, using some nice food-web examples:

What happens at a ‘Whale Fall’?

Whale Fall (after life of a whale) from Sharon Shattuck on Vimeo.

Key terms: ecology, ecosystem, community, biotic, abiotic, species, population, heterotroph, autotroph, detritivore, saprotroph, trophic level, pyramid, energy, nutrient

  1. Ibiology hasnt been working for the past few weeks, The slides are always stuck, Please fix it… I’ve got my IB exams coming up soon,
    Thanks a lot though MisterT

    • Hi Khenny,

      Thanks for letting me know. They were working fine recently, but something is up with SlideShare and WordPress – they are all still OK on the SlideShare page, please just click on the slideshare logo at the bottom of the presentations.


  2. Thanks a lot for your response, Everything works great now!
    We use your site all the time in my school and it is a great asset to us & thanks once again!

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