Ecosystem Ecology: Part 1. September 22, 2014 Mr. Alvarez

Transcription

1 Ecosystem Ecology: Part 1 September 22, 2014 Mr. Alvarez

2 Ecosystems Ecosystem- a particular location on Earth distinguished by its particular mix of interacting biotic and abiotic components.

3 Forest Ecosystem Biotic Trees Wildflowers Birds Mammals Insects Fungi Bacteria Abiotic Sunlight Temperature Soil Water ph Nutrients

4 Large vs Small Ecosystems

5 Photosynthesis vs Cellular Respiration

6 Photosynthesis Producers (autotrophs)- organisms that use the Sun s energy to produce usable forms of energy Photosynthesis- produceers use solar energy to convert carbon dioxide (CO 2 ) and water (H 2 O) into glucose (C 6 H 12 O 6 ) Glucose- a form of potential energy that can be used by a wide range of organisms

7 Photosynthesis Equation light 6 CO H 2 O C 6 H 12 O 6 + 6O 2 Carbon Dioxide + Water light Glucose + Oxygen

8 Cellular Respiration Cellular Respiration- a process that unlocks the chemical energy stored in the cells of organisms EXACT OPPOSITE OF PHOTOSYNTHESIS All organisms, both producers and consumers perform cellular respiration

9 Cellular Respiration Formula 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O + Energy Oxygen + Glucose Carbon Dioxide + Water + Energy

10 Comparing Photosynthesis & Cellular Respiration Photosynthesis Cellular Respiration Function Energy Capture Energy Release Location Chloroplasts Mitochondria Reactants (What goes in) Products (What comes out) CO 2 and H 2 O C 6 H 12 O 6 and O 2 C 6 H 12 O 6 and O 2 CO 2 and H 2 O Equation 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O Energy Captured (In) Released (Out)

11 Consumers Consumers (heterotrophs)- organisms that are incapable of photosynthesis and must obtain their energy by consuming other organisms

12 Trophic Levels Trophic Levels- levels in the feeding structure of organisms. Higher trophic levels consume organisms from lower trophic levels

13 Consumers Primary Consumers (herbivores)- heterotrophs that consume producers Zebras Grasshoppers Tadpoles

14 Consumers cont. Secondary consumers- carnivores that eat primary consumers Lions Hawks Rattlesnakes

15 Consumers cont. Tertiary Consumers- carnivores that eat secondary consumers Bald eagles Alligator Polar Bear

16 Scavengers Scavengers- carnivores that consume dead animals Vultures

17 Detritivores Detritivores- organisms that specialize in breaking down dead tissues and waste products into smaller particles Dung beetle

18 Decomposers Decomposers- complete the breakdown process by recycling the nutrients from dead tissues and wastes back into the ecosystem Fungi Bacteria

19 Feeding Relationships Energy flows through an ecosystem in one direction from the sun or inorganic compounds to producers and then to various consumers

20 Food Chains Food Chain- A series of steps in which organisms transfer energy by eating and being eaten ** Arrows ALWAYS point to organisms RECEIVING the energy**

21 Food Webs Food Webs- A bunch of food chains linking the energy flow of an entire ecosystem together

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23 Ecosystem Productivity Gross Primary Productivity (GPP)- The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time Net Primary Productivity (NPP)- The energy captured by producers in an ecosystem minus the energy producers respire

24 Measuring GPP CO 2 taken up during photosynthesis = CO 2 taken up in sunlight + CO 2 produced in the dark Units = kg C/m 2 /day

25 TOTAL energy captured : Gross Primary Productivity STORED energy ( growth ): Net Primary Productivity

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27 Photosynthesis converts ~1% solar energy into chemical energy (as biomass, avg. composition CH 2 O carbohydrates, sugars/starches)

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29 Energy Transfer Efficiency Biomass- the total mass of all living matter in a specific area NPP establishes the rate at which biomass is produced over a given amount of time

30 Lots of NPP goes in to producing leaves and roots, but most standing biomass is found in roots and stems

31 Standing Crop Standing Crop- the amount of biomass present in an ecosystem at a particular time Standing Crop = amount Productivity = rate of energy production over a span of time

32 Productivity vs Biomass (Standing Crop)

33 NPP measured in grams of carbon ADDED per square meter (gc/m 2 ) each year

34 Ecological Efficiency Ecological Efficiency- the proportion of consumed energy that can be passed from one trophic level to another Only 10% of energy is passed through each level

35 Ecological Pyramid Ecological Pyramid- diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or web

36 Energy Pyramid Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level

37 Biomass Pyramid Biomass- Total amount of living tissue within a given trophic level Quantity expressed in grams per unit area

38 Pyramid of Numbers Based on the number of individual organisms at each trophic level Because each trophic level harvests only about 1/10 of the energy from the level below, it can support only about 1/10 the amount of living tissue

39 The Path of Energy Flow Desert Biomass Pyramid: 15 kg coyote must range ~15 ha to subsist Tertiary consumers = 0.1 g / m 2 Secondary consumers = 1.0 g / m 2 Primary consumers = 10 g / m 2 Primary producers = 100 g / m 2 Tertiary consumers must range over large areas to obtain enough energy to subsist.

40 The Path of Energy Flow Temperate Forest Biomass Pyramid: 15 kg coyote only needs ~1 ha to subsist Tertiary consumers = 1.5 g / m 2 Secondary consumers = 15 g / m 2 Primary consumers = 150 g / m 2 Primary producers = 1,500 g / m 2 Also, possibility of quaternary consumers, like bears.

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