1 / 39

Ecosystems and Human Impact

Explore the repercussions of human interventions on biodiversity, ecosystem complexity, and natural systems. Learn about the delicate balance between human actions and the environment, including the effects of pesticides, predators, and exotic species. Understand the importance of maintaining ecological diversity and the interconnectedness of all living organisms.

sherrya
Download Presentation

Ecosystems and Human Impact

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. Ecosystems andHuman Impact

  2. Humans in the Mix (Are Humans Natural?) • Natural Systems vs. Human Modified Systems… • Impacts on: • Biodiversity: • Genetic Diversity: • Species Diversity: • Ecological Diversity: • variety of different versions of the same genes within a population • varieties of different kinds of organisms within a community / ecosystem • complexity within a community (food chains / webs / trophic levels, number of niches, types of biomass produced

  3. Biodiversity “Hot Spots”

  4. But why do we care about biodiversity? • Keystone Species • Drugs / Medicines ($30m / year!) • Earth is one big ecosystem—every animal has a role: Darwin would say if it didn’t have a role, it wouldn’t be here. • Entertainment / Human Interest…

  5. Laws of Human Ecology • 1st Law of Human Ecology • You Can Never Do Just One Thing • Principle of Interconnectedness • 2nd Law of Human Ecology • There is no “away”

  6. Humans in the Mix Ecosystem Complexity and Resilience (“Natural” Evolution) vs. Ecosystem Simplification (Human Impact)

  7. Simplification. • Overuse of Pesticides • Eliminating Some Predators • Deliberately or Accidentally Introducing New Species • Over-Harvesting Potentially Renewable Resources • Interfering with the Normal Chemical Cycling and Energy Flows First Law of Human Ecology

  8. Pesticides: DDT(DDT: Dichloro-Diphenyl-Trichloroethane) • One of the first synthetic pesticides • Developed in WWII: Malaria, other insects • Applications in Ag Industry Post-War • Nearly wiped out MANY species in U.S.

  9. Impact of DDT • Endangerments / Near extinction of many raptors • Softened egg shells, chicks never develop • Found to be a carcinogen • Banned in U.S. in 1972 Peregrine Falcon California Condor Osprey

  10. DDT: Sidenote • DDT still permitted in many tropical (Global South) countries • Used as deterrent against malaria • 1m people die of malaria worldwide (CDC) every year • 90% in Africa Q: • Is DDT good? • Is DDT bad?

  11. Elimination of Predators “Trophic Cascade” http://www.buzzfeed.com/summeranne/how-wolves-change-rivers-is-the-perfect-explanation-of-ecolo

  12. Canada

  13. Exotic Species Wild Boar

  14. Kudzu

  15. Backyard Bird Feeders? • Natural or Unnatural? • Upsetting the homeostasis of the local ecosystem? • What happens if there are too many birds—and birds from elsewhere? • What happens if you quit feeding them after they multiply?

  16. Over-Harvesting Potentially Renewable Resources

  17. Species Response to Change • Homeostasis The ability for any living thing (ecosystem included) to regulate and maintain a flexible, steady living system • Sustainability: “The capacity to endure”

  18. Species Response to Change • Homeostasis • Stability and Resilience • Inertia (resistance) • Renewal(how well can a given species bounce back?) • Constancy(persistence and stability)

  19. (too much?)Inertia!

  20. Renewal

  21. Constancy

  22. Species Response to Change • Homeostasis • Stability and Resilience • Population Dynamics • Controls • Environmental Resistance • “Carrying Capacity” • Abiotic and Biotic Influences on Plant and Animal Populations

  23. (Relatively) Stable Bobcat Population in Wisconsin

  24. Hare and Lynx Pop: Canada Cyclic

  25. Irruptive Change Curve

  26. Interfering with the Normal Chemical Cycling and Energy Flows

  27. Colorado River

  28. Lake Mead

  29. 2nd Law: Garbage Mountain

  30. The North Pacific Gyre “Garbage Island” http://www.youtube.com/watch?v=Lt-MivNezes&feature=related

  31. Human Impact • With technology, the impact of humans has never been more dramatic • Extinction is “natural,” but the current rate of extinction has never existed due to forces beyond “naturally” occurrences: • Ice age • Asteroid hitting earth? • Eruption and release of global volcanic ash? • Floods? Tsunamis? • Averaging 2-3 extinctions per decade • What’s the final impact if we can “never do just one thing?” http://www.cleanair.org/program/waste_and_recycling/recyclenow_philadelphia/waste_and_recycling_facts

More Related