Energy flow through ecosystems
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

Energy flow through ecosystems PowerPoint PPT Presentation


  • 55 Views
  • Uploaded on
  • Presentation posted in: General

Energy flow through ecosystems. Energy flows through an ecosystem, being transferred from one organism to the next. Energy flows in one direction, obeying the law of conservation of energy. Energy cannot be created or destroyed, only changed from one form to another.

Download Presentation

Energy flow through ecosystems

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Energy flow through ecosystems

Energy flow through ecosystems

Energy flows through an ecosystem, being transferred from one organism to the next.

Energy flows in one direction, obeying the law of conservation of energy.

Energy cannot be created or destroyed, only changed from one form to another.

When energy is converted from one form to another, some is always lost as heat. This inefficiency of transfer limits the number of organisms found in any food chain.


Obtaining energy

Obtaining energy


Energy availability in photoautotrophs

Energy availability in photoautotrophs


Primary production

Primary production


Ecosystem examples

Ecosystem examples

Net primary productivity (NPP) is a good way to compare different ecosystems. The availability of light, water and nutrients are different around the world and therefore the productivity of the world’s ecosystems also varies greatly.

desert ecosystem NPP = 260kJm-2 year-1

tropical rainforest ecosystem NPP = 400,000kJm-2 year-1


Ordering npp of ecosystems

Ordering NPP of ecosystems


Routes of energy transfer

Routes of energy transfer

The net primary productivity represents the potential food available to consumers in the ecosystem. This energy can be transferred to the next trophic level in several ways:

  • The organism is consumed by a primary, secondary or tertiary consumer.

  • Death, production of urine and feces and loss of organic tissue (e.g. fruit fall, hair loss) allows the energy from the organism to be passed on to decomposers.


What is trophic efficiency

What is trophic efficiency?

The rate at which energy is used to make new organic molecules within heterotrophs is known as secondary production.

As with the transfer of energy from the sun to autotrophs, the transfer of energy from one organism to another is inefficient. The efficiency of chemical potential energy transferred between trophic levels can be measured.

energy available after the transfer

× 100

efficiency

=

energy available before the transfer

The energy available is usually measured in kilojoules per square meter per year (kJm-2 year-1).


Loss of energy between trophic levels

Loss of energy between trophic levels?

A large percentage of the energy is lost between trophic levels.

This is as a result of the following:

  • Some of the organism cannot be eaten, e.g. bones, fur, etc.

  • Once eaten, some of the organism cannot be digested.

  • Energy is lost in excretory materials, such as urine.

  • Energy is lost in the form of heat from respiration and body heat.


Comparing trophic efficiencies

Comparing trophic efficiencies


Efficiency of transfers in a food chain

Efficiency of transfers in a food chain


Energy transfer true or false

Energy transfer: true or false?


  • Login