Ecology

1. Ecology

2. Ecology • Scientific study of the interactions between organisms and their environment

3. The Scope of Ecology • Ecology • Reveals the richness of the biosphere • Determine both the distribution of organisms and their abundance

4. The Scope of Ecology • The Precautionary Principle • Basically states that humans need to be concerned with how their actions affect the environment

5. Hierarchy of Ecological Interaction • Individual (of a species) • Population (all individuals in an area of a certain species) • Community (all populations of different species in an area; interactions) • Ecosystem (biological and abiotic interactions- living and nonliving) • Biome (specialized ecosystems in parts of world) • Biosphere (zones of earth)

6. Individual Organism

7. Population

8. Community

9. Ecosystem

10. Biome

11. Biosphere

12. THE ENVIRONMENT

13. Organisms and the Environment • The environment of any organism includes • Abiotic, or nonliving components • Biotic, or living components • All the other organisms living in the environment

14. Biotic Factors • Biotic factors that affect the distribution of organisms may include • Interactions with other species • Predation • Competition

15. W. J. Fletcher tested the effects of two algae-eating animals, sea urchins and limpets, on seaweed abundance near Sydney, Australia. In areas adjacent to a control site, either the urchins, the limpets, or both were removed. EXPERIMENT Fletcher observed a large difference in seaweed growth between areas with and without sea urchins. RESULTS Removing bothlimpets andurchins orremoving onlyurchins increasedseaweed coverdramatically. 100 Seaurchin Both limpetsand urchinsremoved 80 Onlyurchinsremoved 60 Seaweed cover (%) Limpet 40 Almost noseaweed grew in areas whereboth urchins andlimpets werepresent, or whereonly limpets wereremoved. Only limpets removed Control (bothurchins andlimpets present) 20 0 February 1984 February 1983 August 1983 August 1982 Removing both limpets and urchins resulted in the greatest increase of seaweed cover, indicating that bothspecies have some influence on seaweed distribution. But since removing only urchins greatly increased seaweed growth whileremoving only limpets had little effect, Fletcher concluded that sea urchins have a much greater effect than limpets in limitingseaweed distribution. CONCLUSION • A specific case of an herbivore limiting distribution of a food species

16. Abiotic Factors • Abiotic factors that affect the distribution of organisms may include • Temperature • Water • Sunlight • Wind • Rocks and soil

17. Abiotic Factors • Temperature • Effects metabolism • Survival in extremes forces adaptations • Ex. Wood frog • Is an important factor in the distribution of organisms because of its effects on biological processes

18. Abiotic Factors • Water • Solute concentration inside and outside of a water organism • Dryness • Adaptations to retain water • Cuticle on leaves • Skin

19. Abiotic Factors • Sunlight (solar energy) • Controls growth of algae in aquatic environments • Affects photosynthesis • Plant growth

20. Abiotic Factors • Wind • Blows nutrients across land and water • Disperses pollen and seeds • Affects water loss • Damages ecosystems

21. Wind • Wind • Amplifies the effects of temperature on organisms by increasing heat loss due to evaporation and convection • Can change the morphology of plants

22. Abiotic Factors • Rocks and Soil • Limits distribution of plants and animals • Soil variation • Affects plant and animal life in streams and rivers

23. Rocks and Soil • Many characteristics of soil limit the distribution of plants and thus the animals that feed upon them • Physical structure • pH • Mineral composition

24. Abiotic Factors • Periodic Disturbances • Catastrophes • Fires • Hurricanes • Tornadoes • Volcanic Eruptions • Re-colonization occurs

25. Abiotic Factors • Global Climate Patterns • Solar energy and latitude • Seasons • Air circulation • Ocean currents

26. Energy Flow • Where does the energy come from that is needed by particular animals and plants? • Photosynthesis → Respiration H2O + CO2→ C6H12O6 + O2→ H2O + CO2

27. How do organisms obtain energy? • Producers – organisms that take in energy from the sun and store it. • Produce energy via photosynthesis Autotrophs (auto = self, troph = energy) • Ex. plants, algae & some bacteria • Decomposers - a consumer that eats organic wastes and breaks it down to its organic materials. • Ex. bacteria, fungi

28. How do organisms obtain energy? • Consumers – organisms that obtain energy by eating or consuming other organisms. • Produce energy via respiration • Heterotrophs (hetero = other, troph = energy) • Ex. animals, most bacteria & protists and all fungi

29. Trophic Levels • Organisms are assigned to trophic levels. • The first trophic level - producers. • The second trophic level consists of primary consumers. • They are herbivores (plant eaters). • The third trophic level consists of secondary consumers. They eat organisms in the second trophic level. • They are carnivores (meat eaters). • There can be four or five or even more trophic levels. • Most ecosystems do not contain more than 5 trophic levels.

31. Trophic Level Relationships • Animals feed at more than one trophic level and rely on more than one species within a trophic level. • This relationship, which is actually the transfer of energy, can be shown in a food web. • A food chain is one aspect of a food web.

33. Trophic Level Relationships • Energy flows from producers to consumers. • The arrows in a food chain or food web always point in the direction of energy flow. It does not point to what an organism eats.

34. Trophic Level Relationships • At each trophic level, the energy stored in the organism is about 1/10th that of the level below it. • This is measured and illustrated with an ecological pyramid. • Producers are always at the bottom of an ecological pyramid. • Organisms at higher trophic levels are less numerous than those at

38. Assignment – You Need to: • Artistically Create an Environment/Ecosystem (be creative) • Identify a Location, Climate & Size • Have an Energy Flow Diagram & Draw a food web • Identify @ least 3 Producers, Primary, Secondary & Tertiary Consumers (3 for each level) & 2 Decomposers • List the biotic & abiotic factors • How would each organism be affected if a 4th level consumer was added? • Add a Disturbance to your Ecosystem • Look on Whiteboard for more directions on this

39. Aquatic Biomes • Aquatic biomes • Account for the largest part of the biosphere in terms of area • Can contain fresh or salt water • Oceans • Cover about 75% of Earth’s surface • Have an enormous impact on the biosphere

40. Different Biomes • Abiotic and biotic factors influence the structure and dynamics of aquatic biomes • Varying combinations of both biotic and abiotic factors • Determine the nature of Earth’s many biomes • Biomes • Are the major types of ecological associations that occupy broad geographic regions of land or water

41. 30N Tropic of Cancer Equator Continentalshelf Tropic of Capricorn 30S Key Rivers Lakes Estuaries Abyssal zone(below oceanicpelagic zone) Intertidal zone Coral reefs Oceanic pelagiczone Earth’s aquatic biomes

42. Intertidal zone Neritic zone Oceanic zone Littoralzone Limneticzone 0 Photic zone 200 m Continentalshelf Pelagic zone Benthiczone Aphoticzone Photiczone Pelagiczone Benthiczone Aphoticzone (a) Zonation in a lake. The lake environment is generally classified on the basis of three physical criteria: light penetration (photic and aphotic zones), distance from shore and water depth (littoral and limnetic zones), and whether it is open water (pelagic zone) or bottom (benthic zone). 2,500–6,000 m Abyssal zone(deepest regions of ocean floor) (b) Marine zonation. Like lakes, the marine environment is generally classified on the basis of light penetration (photic and aphotic zones), distance from shore and water depth (intertidal, neritic, and oceanic zones), and whether it is open water (pelagic zone) or bottom (benthic and abyssal zones). Many aquatic biomes are stratified into zones or layers defined by light penetration, temperature, and depth

43. Effects of Eutrophication in plants and aquatic • Promotes excessive plant growth and decay, favors certain weedy species over others, and is likely to cause severe reductions in water quality . • In aquatic environments, enhanced growth of choking aquatic vegetation or phytoplankton (that is, an algal bloom) disrupts normal functioning of the ecosystem, causing a variety of problems such as a lack of oxygen in the water, needed for fish and shellfish to survive. The water then becomes cloudy, colored a shade of green, yellow, brown, or red.

44. Effects in Humans and Society • Human society is impacted as well: eutrophication decreases the resource value of rivers, lakes, and estuaries such that recreation, fishing, hunting, and aesthetic enjoyment are hindered.