1. Objectives:1) Explain and illustrate how living systems interact with the biotic & abiotic factors within an environment 2) Explain and illustrate how matter is cycled within an ecosystem 3) Explain and illustrate how energy is transformed and eventually exits an ecosystem

2. Chapter 34  The Biosphere I. Overview: Discovering Ecology A. Ecology is the scientific study of the interactions between organisms and the environment 1. These interactions determine the distribution of organisms and their abundance 2. Modern ecology includes observation and experimentation B. The rediscovery of the nearly extinct harlequin toad in Costa Rica raises many ecological questions 1. What environmental factors limit their geographic distribution? 2. What factors (food, pathogens) affect population size?

3. 1. Levels of organization b. Ecosystem Ecology 1. All the biotic and abiotic things found in a particular place a. Example- Pond 1. What things would be found in a pond ecosystem? a. Plants, bacteria, fish, rocks, O 2, etc a. The biosphere 1. The broadest, most inclusive level 2. Consists of the upper most atmosphere to the deepest parts of the ocean 3. All living things are found in the biosphere a. Not distributed evenly II. The Scope of Ecological Research A. Ecologists work at levels ranging from individual organisms to the planet 2. Emphasizes energy flow and chemical cycling among the various biotic and abiotic components

4. c. Community Ecology 1. All the interacting biotic factors in an area 2. Example- Pond a. What things would be found in a pond community? 1. Fish, plants, bacteria, etc. 3. Deals with the whole array of interacting species in a community d. Populations 1. All the members of a species that live in one place 2. Example- Pond a. What things would be found in a pond population? 1. All the trout 3. focuses on factors affecting population size over time

5. e. Organisms 1. A single member of a species (i.e.- 1 trout) III. Physical & chemical factors influence life in the biosphere A. Life thrives in a variety of habitats 1. To thrive organisms must be adapted for the abiotic factors present in their particular habitat B. Energy source 1. Light the major energy source that powers most ecosystems 2. By what process is this energy source utilized

6. Global warming C. Examples: Yellowstone Ecology B. Disturbances in Ecosystem 1. Consequences to interconnectedness a. disturbance/change in one portion of ecosystem will have affects on other portions of an ecosystem VI. A key theme in ecology A. Interactions 1. Always remember that no organism is isolated a. All biotic and abiotic factors are interconnected within an ecosystem 1. Biotic = Living 2. Abiotic = nonliving 2. Ecologists look at not only the interactions within the ecological levels of organization but also between levels C. Temperature 1. Must be within homeostatic range of organism D. Water 1. All life requires E. Nutrients

7. A. Terrestrial ecosystems 1. The different terrestrial ecosystems that occur on land across the planet are called biomes a. Biomes are major biological communities that occur over wide areas of land B. 7 major biomes 1. Tropical Rain Forest a. Location 1. Near the equator in Asia, Africa,South America, and Central America b. Climate 1. Warm and moist 2. 43-51  F c. Yearly precipitation 1. 100 in VII. Terrestial Ecosystems

8. d. Vegetation 1. Mostly tall trees a. Due to the lack of light on the forest floor very few plants inhabit this area b. Vines, palm trees, leafy trees 2. Epiphytes a. Plants that live on the branches of trees 3. Orchids, ferns, mosses, lichens 2. Temperate Deciduous Forests a. Location 1. Eastern US, Europe, parts of Asia & the southern hemisphere b. Climate 1. Warm summers & cool to cold winters 2. 35-48  F

9. c. Yearly precipitation 1. 30-49 in d. Vegetation 1. Deciduous trees a. Trees that loose their leaves all at once in the fall b. Oak, hickory, elm, willow, cottonwood 2. Shrubs and a variety of plants and herbs 3. Savannas a. Location 1. Africa, South America, Australia b. Climate 1. Hot, alternating wet and dry seasons 2. 41-51  F

10. c. Yearly precipitation 1. 30-60 in 2. More rainfall than deserts but less than rain forests d. Vegetation 1. Grasses and trees 4. Coniferous Forests/Taiga a. Location 1. Northern Europe, Asia, North America b. Climate 1. Cool, short summers and cold, long winters 2. 26-40  F c. Yearly precipitation 1. 8-24 in

11. d. Vegetation 1. Coniferous trees a. Needle-leafed evergreens such as pine trees 2. Shrubs, grasses, flowers, a variety of plants 5. Temperate Grasslands/Prairies a. Location 1. Usually located in the interior of a continent a. In the U.S.  the Midwest

12. b. Climate 1. Dry, hot summers & cold winters 2. 32-46  F c. Yearly precipitation 1. 11-30 in d. Vegetation 1. Mainly grasses and crops 6. Tundra a. Location 1. Northernmost parts of North America & Europe b. Climate 1. Cold, long winters & cool, short summers, with little precipitation 2. 18-40  F c. Yearly precipitation 1. <10 in

13. d. Vegetation 1. Grasses, sedges, dwarf willows, & mosses 7. Desert 1. Location a. North Africa, central Australia, southwestern North America, eastern Asia 2. Climate a. very dry, often hot b. 36-53  F 3. Yearly precipitation a. < 9 in

14. d. Vegetation 1. Succulent plants, mainly cactus a. Succulent= high levels of H20 w/in the plant

15. Succession I. Successional Changes in Communities A. Succession 1. The gradual, sequential growth of species in an area 2. Pioneer species a. Species that predominate early succession b. Small, fast growing, and fast reproducing 1. Lichens, annual grasses/flowers, perennial grasses/flowers

16. B. Primary succession 1. Development of a community in an area that has NEVER supported life previously a. Very, very slow (about 200 years) b. No soil or nutrients have formed yet c. Lichens  annual grasses  perennial grasses  shrubs  trees

17. C. Secondary Succession 1. Development of a community in an area where an EXISTING community has been cleared by a disturbance a. Forest fire, drought, farming, hurricane, etc b. Much faster than primary succession c. Soil has been left intact d. Annual grasses  perennial grasses  shrubs  trees

18. Chapter 37  Community Ecology I. Competition A. −/− B. Ecological niche 1. Sum of an organisms use of the abiotic and biotic resources in its env. C. When would this occur, what would cause 1. When ecological niches of 2 populations overlap & resources limited 2. Organisms within a community will have to compete for resources a. Remember, one of the driving forces behind evolution D. Lowers carrying capacity of populations II. Mutualism A. +/+ B. Corals-Dinoflagellates/Lichen III. Predation A. +/- B. Predators, prey, and natural selection 1. Predators a. Survival depends on ability to capture food b. Natural selection favors traits that make predators efficient at capturing prey

19. C. Mimicry 1. One organism copying another organism D. Plant-Herbivore interactions 2. Prey A. Natural selection favors traits that make prey efficient at avoiding being captured 1. +/- 2. Physical and/or chemical defenses a. Thorns, poison ivy

20. Trophic Levels/Food chains/Food webs I. Producers A. Intro 1. All organisms need food to survive a. Growth, movement, maintenance & repair, etc. 2. What is the ultimate source of energy in an ecosystem? a. The sun’s energy enters into an ecosystem through what organism? b. Plants convert the sun’s energy into what form of energy? 3. Producers a. Autotrophs 1. Any organism within an ecosystem that captures energy to make organic molecules a. Can manufacture their own food b. Examples 1. Terrestrial ecosystem=Plants

21. B. Measuring productivity 1. The amount of energy captured by producers and available to all nonproducers in an ecosystem 2. The amount of biomass in an ecosystem is directly related to productivity 3. What type of ecosystem/Biome would have the highest productivity? II. Consumers A. Heterotrophs 1. Organisms within an ecosystem that obtain organic food molecules by eating other organisms or their waste a. Cannot manufacture their own food 2. 4 categories a. Herbivores b. Carnivores b. Biomass 1. All organic material within an ecosystem a. Will all the energy captured by producers be available no producers 1. Why?

22. c. Omnivores 1. Eat both producers and consumers 2. Examples? d. Detrivores 1. Consumers that eat the “garbage” of an ecosystem a. Dead organisms (plants,animals,etc) and their waste 2. Scavengers and decomposers III. Energy flow A. Intro 1. Once energy enters an ecosystem it must flow through the ecosystem in order for all organisms to obtain energy 2. Trophic levels a. Shows the feeding relationship among organisms consisting of several different levels b. The position of an organism in the sequence of food consumption c. Producers belong at the 1 st trophic level (bottom) 1. Largest group

23. B. Food chains and food webs 1. Food chains a. Shows the feeding relationship among organisms consisting of several different levels 1. Starts with producers b. A single linear transfer

24. 2. Food webs a. Shows the relationship between food chains within an ecosystem C. Quantity of energy transfers 1. Remember, we cannot transfer 100% of energy(food) a. Some energy will always be lost as what? b. 10% rule

25. b. Some of the energy gets used by the organism itself 1. This energy is not available to the next consumer (trophic level) c. Some organisms do not get eaten

26. I. The Water Cycle A. Movement/Recycling of water throughout an ecosystem B. 3 important processes in the water cycle 1. Evaporation 2. Transpiration a. Evaporation of water by a plant 3. Precipitation

27. II. The Carbon Cycle A. Carbon is the building block for all organic compounds B. Movement/recycling of carbon throughout an ecosystem 1. Major source of carbon in an ecosystem is CO 2 C. 2 important processes in the carbon cycle 1. Photosynthesis a. Takes CO 2 out of the atmosphere to make carbohydrates 2. Cellular respiration a. Returns CO 2 into the atmosphere by breaking down carbohydrates

28. III. Nitrogen cycle A. Nitrogen is essential building block for all proteins B. Movement/recycling of nitrogen throughout an ecosystem C. 2 important processes in the nitrogen cycle 1. Nitrogen fixation a. Most nitrogen in an ecosystem not in a usable form 1. A gas in the atmosphere b. Nitrogen-fixing bacteria are the only organisms that can transform nitrogen gas in the atmospohereinto usable nitrogen 1. Release excess nitrogen into soil allowing plants to take up 2. Denitrification a. Process of returning nitrogen back to the atmosphere as a gas b. Bacteria change usable nitrogen back into nitrogen gas by decomposing dead organisms