Ecology

1. Ecology

2. What is Ecology? • Ecology is the study of interactions among organisms and their environments, or surroundings • also includes the study of human interactions and the impact of human activities on the environment

3. The Biosphere The combined portion of the planet where life exists -land, water, atmosphere ect… -extends 8 kilometers above Earth’s surface and 11 kilometers

4. Levels of Organization within the Biosphere • Species- group of organisms so similar they can interbreed and produce fertile offspring • Population- group of organisms of the same species living in the same area • Community- collection of all species populations living in the same area • Ecosystem- living community + nonliving physical environment • Abiotic- nonliving factors • Climate, sunlight, soil composition, nutrients ect… • Biotic- living organisms • community • Biome- group of similar ecosystems with similar climate and similar communities • Usually cover a large geographic area

5. Energy with Ecosystems • Producers (autotrophs)- organisms capable of making their own energy supply • Plants on land and algae in water (photosynthesis) • Consumers (heterotrophs)- organisms that rely on other organisms for food supply (must consume other organisms to obtain energy supplies • Herbivores, carnivores, omnivores, detritivoresect… • Primary, secondary, tertiary ect… • Decomposers- obtain energy by breaking down organic matter • Bacteria & Fungi • Very important- return nutrients to abiotic environment (soil)

6. Relative Importance • Which class of organisms do you feel are most important and why? • Producers- most vital (important) make energy for themselves all other organisms in their ecosystems. • WITHOUT PRODUCERS there is NO OTHER LIFE! • Decomposers- very important because they break down organic matter • Return nutrients to soil/abiotic environment • Consumers- complete the “balance of life” yet are least important

7. The Food Chain • Series of steps that show feeding relationships and flow of energy through an ecosystem • Each STEP IN FOOD CHAIN = TROPHIC LEVEL • Starts with producer • Convert energy from sunlight

8. Food Webs • Show all the feeding relationships or interconnected food chains within an ecosystem

9. Flow of Energy Through an Ecosystem • http://www.youtube.com/watch?feature=player_detailpage&v=De_53QflEXQ

10. Flow of Energy Through an Ecosystem • Energy Flows Through an ecosystem in ONE DIRECTION. • It is not recycled! • Organisms use approximately 90%of the energy they take in for metabolic activity (life processes) • Most of this energy is lost to the environment as heat. • Only about 10% of the energy that an organism takes in is stored in its structures and available for organisms at the next trophic level (step of the food chain) • This relationship can be shown in an energy pyramid

11. The ENERGY Pyramid

12. Matter vs Energy • Unlike Energy, MATTER is RECYCLED in nature • Matter Cycles between abiotic (nonliving environment) and community (living things) • Common Substances Cycle in Nature. • Water • Carbon • Nitrogen • Phosphorus

13. The Water Cycle • Evaporation, Transpiration, Condensation, Precipitation, Water Runoff

14. The Carbon Cycle • In Atmosphere (CO2), Photosynthesis, Food Chain (sugars), Respiration, 3D’s (Death, Dung, and Decay) Burning of Fossil Fuels

15. The Nitrogen Cycle • In Atmosphere (N2), Nitrogen Fixation, Plant Uptake, Food Chain, 3 D’s (Death, Dung, and Decay), Denitrification

16. The Phosphorus Cycle • In Soil, Rocks, and Bodies of Water • Plant Uptake, Food Chain • Death, Dung and Decay

17. Weather vs Climate • Weather- day to day condition @ a particular time and place • Climate- average yr after yr conditions at a particular place • Average temperatures (fall,winter, spring, summer) • Precipitation- amount of rainfall, snow, hail ect..

18. Effect of Climate on Ecosystems • Climate shapes Ecosystems! • Climate is the #1 Abiotic Factor that determines what type of community that will be found in a particular area. • Temperatures and rainfall determine what type of plants (plant life) can be found in an area • This also determines the type of animals and # of animals that can be found in an area

19. Solar Radiation Heats Earth • Earth Heats Atmosphere • Some Heat Trapped in Atmosphere by Greenhouse Gases • CO2, CH4, and N2O • Without greenhouse effect Earth would be VERY COLD!

20. Effect of Latitude on Climate • Near equator the angle of solar radiation is more direct • More solar radiation will penetrate the atmosphere near equator • Warmer an d wetter as a result • 3 distinct zones created (tropical,temperate, and polar)

21. Biomes of the World

22. The Niche • An organism’s “role” within the ecosystem • Feeding Relationships • Where does it belong in food chain • Physical requirements (temperature, shelter, ect…) • Other relationships with other species

23. Community Interactions • Competition- organisms of the same or different species trying to use the same resource at the same time • Water, nutrients, light, food, space ect… • Predation-one organism captures and feeds upon another organism • Ex: Deer and wolf • Predator-Wolf • Prey-Deer

24. Community Interactions Cont… • Symbiosis-when two organisms live close to one another and have some sort of Relationship • Mutualism- a relationship in which both species benefit • Ex: Oxpecker and cattle • Commensalism- a relationship in which one species benefits and the other is neither helped not harmed • Ex: Tree and bird • Parasitism- a relationship in which one species benefits and the species is harmed • Parasite vs Host • Ex: Tapeworm (parasite) and Animals (Host)

25. Ecological Succession • Ecological Succession- changes in a community after human or natural disturbances • Usually changes are predictable • Simple to complex • Can be Primary or Secondary

26. Primary Succession • Primary succession- no soil present • Follows volcanic lava flows or eruptions • Pioneer species- 1st species to populate the area • Lichens, bacteria • Other species follow as rock is weathered to create soil that is suitable • Lichens  grasses  small shrubs  trees ect… • This process is SLOW • Eventually Reaches Climax Community • Climax Community- steady community with lots of diversity and many community interactions

28. Secondary Succession • Secondary Succession- Soil is already present • Follows Forest Fires, Floods, Changes in Abiotic Environment, Human Disturbances ect.. • Occurs much, much faster than primary succession • Soil is already present

30. Population Growth • 4 Factors that influence the growth of a population • Immigration- individuals moving Into a population • Emigration- individuals leaving or Exiting the population • Birth Rate- Individuals being born per year • Death Rate- individuals dying per year

31. Types of Population Growth • Exponential Growth • Continuous growth • Must have unlimited resources and no limiting factors restricting a populations size/growth -not usually realistic in nature

32. Types of Population Growth • Logistic Growth • begins w/ rapid grow • exponential phase • Carrying Capacity- max # of individuals that ecosystem support • growth rate slows as population size nears carrying capacity. WHY? • Limiting Factors- limit pop. growth • predation, competition, parasitism & disease • Natural disasters, unusual weather and/or climate change, and human activity

33. Logistic Growth (cont.) • Slight fluctuation near carrying capacity is normal • Population could “crash” and reenter exponential phase

34. Biodiversity • All the different species living on Earth • Human activity has significantly lowered the amount of biodiversity on Earth. • Are we currently causing a mass extinction? • Extinction is a natural process but… • It is estimated that human activity has increased the rate of extinction by 1,000 to 10,000 times the natural rate • 30-50% of all species will be extinct by mid century (2050)

35. Who Cares? • Human survival is tied to biodiversity • Humans are dependent upon living things for: • Natural resources • Food and goods • Pharmaceuticals (medicines)

36. Human Actions • Habitat Destruction/Alteration- This is the leading cause of extinction. • Urban development • Industrial development • Dams/Alteration of Aquatic Environments • Agricultural Development • Deforestation • Habitat Fragmentation- splitting of ecosystems into pieces (islands) • many organisms such as GRIZZLIES need a large area to survive. • Fragmentation can equal extinction

37. Overfishing/Overhunting/Poaching

38. INVASIVE (nonnative) SPECIES • Introduction of Invasive (nonnative) species has a negative impact on ecosystems • Invasive species can outcompete native species and disrupt balance or relationships within a natural ecosystem

39. Pollution • Acid Rain • Chemicals within smog combine with water from rain to form nitric and sulfuric acid • Changes acidity of marine systems and terrestial systems • Toxic Waste • Biological Magnification- build up of toxins as they pass through food chain • Some toxins do not degrade • These toxins reach lethal level as they reach upper levels of a food chain • Example- DDT

40. OZONE DEPLETION • CFC’s and other Air Pollutants destroy the ozone layer • Ozone (O3) is in the upper layer of the atmosphere and deflect much solar and UV radiation • CANCER KILLS • ALSO Contributes to global warming

41. GLOBAL WARMING • Burning of Fossil Fuel INCREASES CO2 levels in the atmosphere • CO2 is a greenhouse gas and traps heat • Excess CO2is causing global climate change is taking place

42. Conservation Efforts • Today, focus is on saving entire ecosystems in addition to single species • Ecological Reserves • National Parks Ect… • Doing so preserves relationships in nature and provides an increased chance of saving many species.

43. What have you done lately? • Interested in more? • AP Environmental Science