1 / 42

Herbivory in an Elevated CO 2 World

Herbivory in an Elevated CO 2 World. Rick Lindroth University of Wisconsin. Herbivory in an Elevated CO 2 World. Herbivory in an ecosystem context Consequences of current changes in CO 2 for plants Consequences of current changes in CO 2 for herbivores

wyanet
Download Presentation

Herbivory in an Elevated CO 2 World

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Herbivory in an Elevated CO2 World Rick Lindroth University of Wisconsin

  2. Herbivory in an Elevated CO2 World • Herbivory in an ecosystem context • Consequences of current changes in CO2 for plants • Consequences of current changes in CO2 for herbivores • Consequences of current changes in CO2 for natural enemies

  3. Herbivory in an Elevated CO2 World • Consequences of warmer temperatures for herbivores • Evolutionary changes in plant quality and availability in response to CO2 • Evolutionary responses of herbivores to changes in CO2

  4. Herbivory in an Elevated CO2 World • Herbivory in an ecosystem context • Consequences of current changes in CO2 for plants • Consequences of current changes in CO2 for herbivores • Consequences of current changes in CO2 for natural enemies

  5. Net primary production: • Quality • Quantity Atmospheric CO2 Respiration Decomposition Herbivory Photosynthesis Nutrient availability Interacting processes affecting carbon cycling and storage in ecosystems

  6. Atmospheric CO2 Interacting factors affecting herbivores and ecosystem dynamics Altered plant: physiology phenology tissue chemistry survival growth/allocation reproduction population dynamics evolution Altered community: structure function succession Altered herbivore: host selection consumption food utilization survival growth reproduction population dynamics evolution Climate Biogeochemical cycling Altered natural enemy: functional response numerical response

  7. Nutrients (e.g., protein, carbohydrate) Chemical defenses (e.g., phenolics, alkaloids) Physical defenses (e.g., fiber, trichomes) Spatial Temporal Determinants of food consumption by herbivores Quality Availability

  8. Herbivory in an Elevated CO2 World • Herbivory in an ecosystem context • Consequences of current changes in CO2 for plants • Consequences of current changes in CO2 for herbivores • Consequences of current changes in CO2 for natural enemies

  9. Responses of plant chemistry to enriched CO2 Constituent Nitrogen Starch Phenolics Terpenes Trend Decrease Increase Increase No change n.b. Magnitude of change differs among species and in relation to resource availability.

  10. Kinney and Lindroth 1991

  11. Source: Lindroth et al. 2001

  12. Source: Lindroth et al. 2001

  13. Will enriched CO2 alter plant availability?

  14. Herbivory in an Elevated CO2 World • Herbivory in an ecosystem context • Consequences of current changes in CO2 for plants • Consequences of current changes in CO2 for herbivores • Consequences of current changes in CO2 for natural enemies

  15. Responses of insect herbivores to enriched CO2 • Chewing insects: • Increased consumption • Prolonged develop. time • Reduced/unaltered growth • Reduced growth efficiency • Reduced survival • Sucking insects: • Reduced develop. time • Increased popul. density n.b. Responses are highly variable among plant and insect species.

  16. Herbivory in an Elevated CO2 World • Herbivory in an ecosystem context • Consequences of current changes in CO2 for plants • Consequences of current changes in CO2 for herbivores • Consequences of current changes in CO2 for natural enemies

  17. Atmospheric CO2 Interacting factors affecting herbivores and ecosystem dynamics Altered plant: physiology phenology tissue chemistry survival growth/allocation reproduction population dynamics evolution Altered community: structure function succession Altered herbivore: host selection consumption food utilization survival growth reproduction population dynamics evolution Climate Biogeochemical cycling Altered natural enemy: functional response numerical response

  18. Insect herbivores and natural enemies

  19. Herbivory in an Elevated CO2 World • Consequences of warmer temperatures for herbivores • Evolutionary changes in plant quality and availability in response to CO2 • Evolutionary responses of herbivores to changes in CO2

  20. Effects of warming on availability of high quality food

  21. Effects of warmingon geographic range Twentieth-century changes in the range of Pararge aegeria in Great Britain. A colored grid cell indicates more than one population in 1915-1939 (black), 1940-1969 (red) or 1970-1997 (green). Source: Parmesan et al. 1999

  22. Herbivory in an Elevated CO2 World • Consequences of warmer temperatures for herbivores • Evolutionary changes in plant quality and availability in response to CO2 • Evolutionary responses of herbivores to changes in CO2

  23. Resource availability theory Resource availability is the major factor influencing the evolution of both the type and amount of plant defense (Coley et al. 1985). Determinants • Inherent growth rate • Absolute resource availability • Relative resource availability (C:N)

  24. History of atmospheric CO2 concentrations Source: Ehleringer 2001

  25. Evolution of defensive chemicals in plants From: Swain, T. 1978 * Age of dominance (MYA)

  26. Evolutionary changes in plant availability Proliferation of C4 grasses 6-8 MYA

  27. Herbivory in an Elevated CO2 World • Consequences of warmer temperatures for herbivores • Evolutionary changes in plant quality and availability in response to CO2 • Evolutionary responses of herbivores to changes in CO2

  28. Did alkaloids contribute to the demise of dinosaurs? Source: Raven and Johnson 1989

  29. Coevolution between Phyllobrotica leaf beetles and Lamiales host plants Source: Farrell et al. 1992

  30. Fossil records of insect feeding indicate higher frequency and greater diversity of damage in warmer climates. Source: Wilf & Labandeira, 1999

  31. Global expansion of grasslands accompanied by evolutionary radiation of grazing mammals 6-8 MYA.

  32. Turnover rates of mammalianspecies, 6-8 MYA Source: Cerling & Ehleringer, 2000

  33. Summary • Atmospheric CO2 alters the chemical composition of plants, and differentially so among genotypes and species. • Over geologic history, major shifts in atmospheric CO2 have led to changes in defense strategies of plants, as well as shifts in the abundance/distribution of plants. • Changes in plant chemistry due to high CO2 reduce the quality of plants as food for most herbivores, although the magnitudes of change vary among plant and herbivore species.

  34. Summary (cont.) • Warming temperatures over the short term will shift the temporal availability of high quality foods, with the most detrimental impact on mammalian herbivores. • Warming temperatures over the long term will shift species composition and spatial availability of foods, with increased feeding by (insect) herbivores. • Evolutionary changes in the quality and availability of plants elicited attendant changes in the evolution of insect and mammalian herbivores.

  35. The End

More Related