1. Use the diagram to answer the following questions: 1.How much solar radiation is being emitted? 2.What happens to 67J of solar energy? 3.What percentage of incoming solar energy is reflected by the clouds and atmosphere? 4.How much energy is absorbed by the surface? 5.Will all the energy absorbed at the surface be used by plants? Why/why not? All the solar energy is measured in Joules.

2. Ecological energetics - Learning outcomes You should all be able to: Describe the transfer and transformation of energy through an ecosystem Most of you should be able to: Distinguish between storages and flows in energy-flow diagrams Construct and analyse simple energy flow diagrams Some of you might be able to: Explain the transfer and transformation of energy as it flows through an ecosystem

3. Only around 0.06% of the solar radiation falling to the Earth is captured by plants. What happens to the other 99.04%? What happens to that small amount of energy as we move through the trophic levels? 0.9% 0.009% 0.01% 0.1% 0.09%

4. Remember… Energy continually flows through a system. We give out energy all the time. How? How is energy stored within organisms? Materials (matter), e.g. nutrients, oxygen, carbon dioxide or water are cycled and recycled within ecosystems. Which arrows represent energy and which represent matter? How do you know?

5. What happens to the energy? 1 st law of thermodynamics? Energy is neither created nor destroyed but can be changed from one form to another So… how is the light energy entering the planet transformed?

6. What happens to the energy? 2 nd law of thermodynamics? The efficiency of energy conversion to useful work is never perfect So what does that mean for the energy as it moves through the trophic levels? What does that mean about the number of trophic levels in a food chain?

7. Conversion of energy into food Efficiency of conversion of energy to food is low… About 2-3% in terrestrial systems and 1% in aquatic systems. Why do you think it is lower in aquatic systems?

8. Energy flow diagrams… Producers (autotrophs) Primary consumers (herbivores) Secondary consumers (carnivores) DOM Heat and respiration Light Food Death Death and faeces How are the storages represented? How are the flows represented? Why are the arrows different sizes?

9. energy flow model Construct an energy flow model to represent all these data The data in the table below relate to the transfer of energy in a small clearly defined habitat. The units in each case are in kJ.m -2.yr -1 Trophic Level Gross Production Respiratory Loss Loss to decomposers Producers 6072436120477 Herbivores 21762147003072 First Carnivores 71457642 Top Carnivores 741 Respiratory loss by decomposers 3120

10. ProducersHerbivores 1st.CarnivoresTopCarnivores Decomposers 60724 R=36120 477 21762 R=14700 3072 714 R=576 42 7 R=4 1 R=3120 ENERGY FLOW MODEL