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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 5: A 'reduced form' ecosystem model for savannas under climate change

                          Duration: 00:01:01


                          Ecosystem models can often be very complicated, requiring hundreds of parameters. Can we make a simple one, just for African savannas, that is nevertheless realistic in its main features? This is called a 'reduced form' model.

                          The functional types for this system are obviously restricted to those occurring within the savanna region, but they were significantly expanded beyond the generic global types. This model includes the effects of temperature, rainfall, seasonality, carbon dioxide, soil texture, fire regimes and megaherbivores. The equations used to integrate these are "quasi-mechanistic" in nature. That is, they are simple , reduced forms of the mechanistic processes that work within plants, and describe the emergent properties that are observed at an ecosystem scale. The model was run with a timescale step of a single year (hence seasonal effects were implied within the model but not actually calculated separately), and the spatial scale of the model was a "patch" of land.