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Table of Contents

  1. Introduction: AIACC: Climate Change and Conservation Planning
    1. Chapter1: Evidence for climate change
      1. Chapter 2: Global circulation models
        1. Chapter 4: Biodiversity responses to past changes in climate
          1. Chapter 5: Adaptation of biodiversity to climate change
            1. Chapter 6: Approaches to niche-based modelling
              1. Chapter 7: Ecosystem function modelling
                1. Slide 1: Ecosystem function modelling
                2. Slide 2: Aspects and levels of biodiversity
                3. Slide 3 : Dynamic Vegetation Models
                4. Slide 4: DGVMs continued...
                5. Slide 5: A 'reduced form' ecosystem model for savannas under climate change
                6. Slide 6: Basic savanna system model
                7. Slide 7: Water balance modelling
                8. Slide 8: Controls on grass growth at the annual timescale
                9. Slide 9: Linear relation between grass production and rainfall
                10. Slide 10: Slope: Rain Use Efficiency (g/m2/mm)
                11. Slide 11: Intercept: dependent on soil water holding capacity; co-varies with the rain use efficiency
                12. Slide 12: Effect of trees on grass
                13. Slide 13: Maximum tree basal area
                14. Slide 14: What controls the growth rate of trees?
                15. Slide 15: Effect of CO2 on NEP
                16. Slide 16: Effects of temperature on NEP
                17. Slide 17: What controls tree mortality?
                18. Slide 18: Mammal dynamics
                19. Slide 19: Keeping it together!
                20. Slide 20: Test 1: trees, grass and fire
                21. Slide 21: Test 2: + herbivores, carnivores
                22. Slide 22: Test 3: + elephants
                23. Slide 23: The experiment design
                24. Slide 24: Change in production drivers
                25. Slide 25: Change in vegetation structure
                26. Slide 26: Change in herbivores
                27. Slide 27: Preliminary conclusions
                28. Slide 28: Test yourself
                29. Slide 29: Links to other chapters
              2. Chapter 8: Climate change implications for conservation planning
                1. Chapter 9: The economic costs of conservation response options for climate change
                  1. Course Resources
                    1. Practical: Conservation for Climate Change
                      1. Tests to Assess your Understanding
                        1. How to run a GAM model in R

                          Slide 19: Keeping it together!

                          Duration: 00:00:55


                          When you build even a moderately complex food web model, you soon find out that it is very hard to keep all the pieces coexisting. If you have two types of herbivore eating one grass resource, one will soon outcompete the other. So there must be some resource partitioning, although it is possible for each herbivore to share some of its optimal forage with other types.

                          You can balance this by making one more preferred by a predator. Predators are likely to prefer the faster-growing prey, for the simple reason that it is likely to be more available for consumption. This is included in the model by a preference term for predators, such that its preference for a species is a function of its representivity in the total herbivore population.

                          Finally, predators in general are much longer-lived than herbivores, and are also proportionally slower growing - if the predators have a fast growth rate, they will go into a 'boom-and-bust' cycle with the prey.