1. Ecosystems

2. Do Now What composes an ecosystem? What are some organisms that can survive in our backyard, but not in other places in the world? What are some organisms that could not survive in our backyard? Why?

3. Climate Many organisms require a specific set of environmental conditions in order to grow. In an atmosphere, temperature, precipitation, and other environmental factors combine to produce weather and climate Weather = day to day conditions of Earth’s atmosphere at a particular time and place –Solar energy from sunlight and atmospheric gases effect temperature, weather, and climate Climate = average conditions of temperature and precipitation in a particular region –Factors of climate include trapped heat, latitude, winds, currents, elevation, and precipitation

4. Greenhouse Effect Temperature on Earth remains within a livable range because the biosphere has an insulating atmosphere Carbon dioxide, methane, water vapor, and some other atmospheric gases trap heat energy and maintain Earth’s temperature range Greenhouse effect = natural situation where a layer of greenhouse gases retain heat energy from sunlight inside the Earth’s atmosphere

5. Latitude Remember: Earth is a sphere tilted on its axis, so solar energy reaches different parts at different angles, resulting in different heating distributions Earth has three main climate zones: –Polar = cold areas at the poles of the Earth where the sun’s rays strike Earth at a very low angle –Temperate = between polar and tropic zones, more affected by changing angle of the sun during the year, so ranges from hot to cold depending on the season –Tropical = near the equator receiving more direct sunlight, so the climate mostly warm all year

6. Winds and Currents The unequal heating of Earth’s surface drives winds and ocean currents, which transport heat throughout the biosphere Wind forms because warm air near the equator rises and cool air over the poles sinks towards the ground Ocean currents form because cold water near the poles sinks and flow along the ocean’s bottom and rises in warmer water

7. What shapes an ecosystem? Remember: Ecosystems are influenced by a combination of biological and physical factors Biological influences on organisms within an ecosystem = biotic factors –The ecological community ex. Birds, trees, mushrooms, bacteria, frogs, etc. Physical, or nonliving, factors that shape ecosystems = abiotic factors –Climate, temperature, precipitation, humidity, wind, nutrient availability, soil type, sunlight, water Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives

8. What shapes an ecosystem? The area where an organism lives including biotic and abiotic factors = habitat (“address”) The full range of physical and biological conditions in which an organism lives and the way the organism uses those conditions = niche (“occupation”) –Ex. Place in food web, range of temperatures for survival, type of food it eats, how it obtains food, physical environmental condition requirements The combination of biotic and abiotic factors determines the number of different niches No two species can share the same niche in the same habitat, however, different species can occupy niches that are very similar, but are still different niches

9. Quick Activity Describe the biotic and abiotic factors in an ecosystem you know… Describe the habitat and niche of an organism you know…

10. Community Interactions When organisms live together in ecological communities, they interact constantly, helping shape the ecosystem Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem

11. Competition Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time –Resource = any necessity of life (water, nutrients, light, food, or space) Direct competition usually results in a winner and a loser (the loser fails to survive) The competitive exclusion principle = no two species can occupy the same niche in the same habitat at the same time

12. Predation An interaction in which one organism captures and feeds on another organism –Predator = organism that does the killing and eating –Prey = organism that is the food

13. Symbiosis Any relationship in which two species live closely together Symbiosis = “living together” The types of symbiosis include: –Mutualism –Commensalism –Parasitism

14. Mutualism In this relationship both organisms benefit from the association. (+,+)

15. Commensalism In this relationship one organism is benefited and the other is neither helper nor harmed. (+, 0)

16. Parasitism In this relationship, the parasite benefits at the expense of the host. (+, -)

17. Ecological Succession Ecosystems and communities may appear stable temporarily, but they are always changing due to abrupt or human disturbances or natural fluctuations in the environment As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community = ecological succession –Primary succession = occurs on bare rock –Pioneer species = first species to populate an area (lichens) –Secondary succession = a disturbance changes an existing community –Climax community = mature, stable community after specific, predictable stages of succession

18. BIOME OUR PLANET HAS AMAZING DIVERSITY OF ORGANISMS THAT LIVE IN MANY DIFFERENT ECOSYSTEMS THE VARIETY OF ECOSYSTEMS ARE CLASSIFIED INTO CATEGORIES CALLED BIOMES BIOMES = PARTICULAR PHYSICAL ENVIRONMENT THAT CONTAINS CHARACTERISTIC PLANTS AND ANIMALS THE BIOME IS ALSO THE MOST COMMON CLIMAX ECOSYSTEM THAT WILL FORM IN LARGE CLIMATIC AREAS. CLIMATE DIAGRAM = GRAPH SUMMARIZING TEMPERATURE AND PRECIPITATION IN SPECIFIC BIOMES

19. TERRESTRIAL BIOMES TERRESTRIAL BIOMES ARE THOSE BIOMES THAT FORM ON LAND. THE MAJOR PLANT AND ANIMAL ASSOCIATIONS (BIOTIC FACTORS) ON LAND ARE DETERMINED BY THE MAJOR CLIMATE ZONES OF THE WORLD, MODIFIED BY LOCAL LAND AND WATER CONDITIONS. CLIMATES WILL VARY AS TO TEMPERATURE, SOLAR RADIATION, AND PRECIPITATION. THE PRESENCE OR ABSENCE OF WATER IS A MAJOR LIMITING FACTOR FOR TERRESTRIAL BIOMES.

20. MAJOR LAND BIOMES TROPICAL RAIN FOREST TROPICAL DRY FOREST TROPICAL SAVANNA DESERT TERMPERATE GRASSLAND TEMPERATE WOODLAND AND SHRUBLAND TEMPERATE FOREST NORTHWESTERN CONIFEROUS FOREST BOREAL FOREST (TAIGA) TUNDRA

21. Aquatic Ecosystems Habitats in water environments Aquatic ecosystems are determined primarily by the depth, flow, temperature, and chemistry of the overlying water (abiotic factors)

22. Major Aquatic Biomes Freshwater Estuaries Marine water

23. Freshwater ecosystems Flowing-water ecosystems = rivers, streams, creeks, etc –Organisms are well adapted to the rate of flow –Usually turbulent water at beginning with plenty of oxygen –As water flows downhill, it slows and sediments build up, plants grow, and organisms can make homes Standing-water ecosystems = lakes and ponds with water circulating within them –Water circulation distributes heat, oxygen, and nutrients –Phytoplankton = single celled algae forming base of aquatic food webs –Zooplankton = planktonic animals that feed on phytoplankton –Plankton = tiny, free-floating or weakly swimming organisms that live in both freshwater and saltwater environments

24. Freshwater wetlands Freshwater wetlands = water covers soil or it is present near the surface of the soil for part of the year and are usually breeding grounds for insects, fishes, amphibians, and migratory birds –Bogs = form in depressions left by ice that melted thousands of years ago –Marshes = shallow wetlands along rivers and contain cattails –Swamps = water flows slowly and tress and shrubs are present

25. Estuaries Brackish wetlands formed where rivers meet the sea (mix of fresh and salt water) Detritus = tiny pieces of organic material that provide food for organisms at the bottom of estuary’s food web (worms, clams, sponges) Serve as spawning and nursery grounds –Salt marshes = temperate-zone, grasses above tide and seagrasses under water –Mangrove swamps = coastal, tropical zone, mangrove trees

26. Marine ecosystems Photic zone = well-lit upper layer where photosynthesis can occur allowing algea and other producers to grow –Intertidal zone = organisms are submerged part of the day and exposed to air, sunlight and temperature changes the remainder of the day while battered by waves –Coastal ocean = rich in photosynthetic organisms, plankton, and other organisms including kelp forests and coral reefs Aphotic zone = permanently dark where chemosynthetic autotrophs survive –Open ocean = aka “oceanic zone” = largest marine zone with low nutrients, small producers, low productivity, fish of all shapes and sizes (swordfish to octopus to dolphins to whales) –Ocean trench = high pressure, frigid temperatures, and total darkness with chemosynthetic producers –Benthic zone = ocean floor contains benthos (sea stars, anemones, marine worms) feeding on detritus that drifts down from the produces near the surface