Human Impact on the Environment

1. Human Impact on the Environment

2. How is the human population impacting the Earth? • The growing human population is exerting pressure on Earth’s natural resources • We are using the non renewable resources at a faster rate than can be created • Renewable resources are being used, but not at the same rate as non renewable.

3. Types of Resources • Renewable: replaced by natural processes Ex: plants/crops, water

4. Types of Resources • Nonrenewable: only available in limited amounts and take a long time to form. Formed from carbon forms ofdead organisms Ex: Metals, minerals, topsoil, fossil fuels Fossil fuels Coal

5. Types of Pollution • Pollution: contamination of soil, water, air • Industrialization- a major source of pollution.

6. Types of Pollution • Air Pollution: • Primary cause is burning of fossil fuels for electricity • Other contributors- cars, heating homes, planes • Particulates-solid particles of soot • Smog-smoke, gases, fog

7. Air Pollution Causes Acid Rain • Pollutants from factories and cars release and mix with oxygen and nitrogen in the air to form sulfur and nitric oxides  converts into sulfuric and nitric acid results in acid rain when precipitation occurs • pH of rain changes from slightly acidic (6.5) to below 6.

8. Results of Acid Rain • Upsets the environmental conditions that living things are in within water environments • Can result in death of organisms that require a highly specific environment to thrive in

9. Air Pollution From Excess Carbon Dioxide • Greenhouse effect- natural warming of the Earth due to carbon dioxide being trapped within Earth • Most of the greenhouse gases leave but in excess they build up and warm up the Earth • Increased CarbonDioxide from increased burning of fossil fuel leads to global warming- Earth becomes warmer over time due to change in carbon dioxide level

11. Air Pollution Due To Excess CFC’s • Ozone layer- prevents lethal doses of UV radiation from reaching earth • Thinning of ozone caused by release of CFC’s (chlorofluorocarbons) from aerosol cans, and cooling refridgerants into the atmosphere. • Can lead to higher rates of skin cancer because of excess UV radiation.

12. Water Pollution • Non-point pollution- from many sources and not easily identifiable • Example- homes, lawns, highways, pesticides, fertilizers. • When fertilizer and pesticides are used on plants the excess can runoff into water systems and change water environment for organisms.

13. Impacts of Pollutants in Ecology • Biomagnification – as pollutants move up a food chain, its concentration increases

14. Results of Biomagnification • As the pollutant or toxin is taken into an organisms body it enter its cells • As higher order organisms obtain energy from lower order organisms, the pollutant/toxin is passed on and magnified due to the organisms usually increasing in size moving up a food chain/web. • Results in overall magnification of the toxin through the chain or web

15. The Gulf Oil Spill Disaster • http://planetgreen.discovery.com/videos/disaster-in-the-gulf-the-oil-spill-environmental-impact.html

16. What can be done?Three R’s of conservation

17. Human Impact Effects on Plants and Animal Life • Biodiversity- the variety of life in an area • Most diverse areas of the world are tropical rainforests • Biodiversity is being lost due to human actions like deforestation, overhunting, overfishing, introducing a species

18. How do we negatively impact biodiversity? • Deforestation: clearing of trees for open land space loss of animal habitat and niches • Overhunting/overfishing interrupt predator prey relationships by influencing population dynamics • Introduced Species: when we introduce a new species that does not have a natural predator overpopulation of that new species occurs. May take over other organisms niche, habitat, food resource

19. Effects of An Introduced Species

20. Importance of biodiversity • Loss of species may have consequences for others living things (e.g.food chains and webs are disrupted)

21. Plant and Animal Responses To A Changing Biosphere • Plants tropism and normal adaptation responses may be altered due to drastic environmental changes • Animals Normal animal behavior may be altered due to drastic environmental changes

22. PLANT RESPONSES & ADAPTATIONS: • Tropism: Plant’s response to its environment • Geotropism- Response to gravity; roots down, stems up • Phototropism- Response to light; sunflower “heads” turning toward sun • Thigmotropism- Response to touch; vine climbing trellis • Hydrotropism- the way a plant grows in response to water

24. PLANT RESPONSES & ADAPTATIONS: • Auxins- Hormones regulate tropisms • Gibberellin- causes plant growth • Abscisic acid- inhibits plant growth

25. Normal Plant Responses and Adaptations Plant Adaptations: • Dormant in drought • Deciduous trees- Drop leaves in winter • Thick bark to protect from fire • Flexible branches of conifers to bend with ice and snow • Cuticle- waxy coating on needles (leaves) • “hitchhiker” seeds, some blow in wind, float, etc to disperse seeds • bright colors and fragrance in flowers to attract pollinators • nutrient exclusion – some plants aren’t worth eating (no nutritional value) • These adaptations may be challenged due to a changing biosphere

26. Normal Animal Behavior: • Inherited or innate behavior- automatic responses, reflexes, and instincts Ex: courtship, spider web, nest building, response to heat, blinking • Territorial behavior-: aggression, defend/ mark territory, efficient use of resources, decreases competition

27. Animal Behavior: • Migration: instinctive, seasonal movement; affected by hormones, length of day, changing environmental conditions, geographical clues, use of magnetic field • Hibernation and Estivation: Long term vs short term lowered metabolism, • stimulus – winter vs shorter periods of drought or lack of food

28. Animal Behavior: Learned Behavior: Habituation (deer feeding in yards), imprinting (turtles and salmon returning to birthplace to reproduce/spawn)

29. Animal Behavior • Adaptations for defense: • Mechanical defenses: physical structures like claws, teeth, sharp tusks, stingers, shells

30. Animal Behavior • Camouflage: blend with environment • cryptic coloration- same color or pattern as background • Disruptive coloration- color patterns disguise silhouette, ex- herd of zebra • Countershading two-toned, Ex- fish dark on top, light on bottom

31. Animal Behavior • Schools and Herds- big group confuses predators

32. Animal Behaviors • Chemical Defenses: neurotoxins, poisons, venom, poisonous fish; bombardier beetles, wasps and bee stings, plants foul tasting chemicals

33. The Overall Bottom Line • Our actions not only affects our species, but all other factors (biotic/abiotic) that are on Earth. • The more damage we do to our biosphere (Earth) by our actions, the longer it will take for it to be fixed. • Actions must be taken now so that we save what we have on Earth.