Ecosystems: What Are They and How Do They Work?

Ecosystems: What Are They and How Do They Work?
Chapter 3 Ecosystems: What Are They and How Do They Work?

Core Case Study: Have You Thanked the Insects Today?
Many plant species depend on insects for pollination and plant reproduction. Insects can control other pest insects by eating them. They also mix up the soil Figure 3-1

Core Case Study: Have You Thanked the Insects Today?
…if all insects disappeared, humanity probably could not last more than a few months [E.O. Wilson, Biodiversity expert]. Insect’s role in nature is part of the larger biological community in which they live. why are honeybees dis.flv honeybees part 2.flv

THE NATURE OF ECOLOGY Ecology is
How organisms interact with one another and with their nonliving environment. Figure 3-2

So, really intricate and amazing interrelationships occur between plants and animals.

Well, as mentioned earlier, plants rely on insects, birds, and rodents for pollination
Fynbos biome

And, of course birds and animals need plants……what what

Biosphere!!!!!!!

Re-wind: from this diagram I would like you to remember the differences between good and bad ozone, and the greenhouse vs. the ozone layer

What Happens to Solar Energy Reaching the Earth?
Warms and lights up the troposphere Drives the cycling of matter Evaporates water and drives weather and climate 1% generates winds Green plants/algae use less than .1% in photosynthesis Figure 3-8

Falling leaves and twigs Soluble mineral nutrients
What are the abiotic factors in this diagram? Oxygen (O2) Sun Producer Carbon dioxide (CO2) Secondary consumer (fox) Primary consumer (rabbit) Precipitation Producers Falling leaves and twigs Figure 3.10 Natural capital: major components of an ecosystem in a field. Soil decomposers Water Soluble mineral nutrients Fig. 3-10, p. 57

Factors That Limit Population Growth
Availability of matter and energy resources can limit the number of organisms in a population. Examples of limiting factors: (temperature, sunlight, nutrients, dissolved oxygen, salinity…etc) Figure 3-11

Lower limit of tolerance Upper limit of tolerance
No organisms Few organisms Few organisms No organisms Abundance of organisms Population size Figure 3.11 Natural capital: range of tolerance for a population of organisms, such as fish, to an abiotic environmental factor—in this case, temperature. These restrictions keep particular species from taking over an ecosystem by keeping their population size in check. Zone of intolerance Zone of physiological stress Optimum range Zone of physiological stress Zone of intolerance Low Temperature High Fig. 3-11, p. 58

Producers: Basic Source of All Food
Most producers capture sunlight to produce carbohydrates by photosynthesis: KNOW THE FORMULA

Write the chemical equations for photosynthesis and respiration
Write the chemical equations for photosynthesis and respiration. Explain how these two processes are intertwined; include the terms oxygen, carbon dioxide, light reaction, dark reaction, chloroplasts, mitochondria, photosynthesis, respiration, glucose, water, sunlight, ATP, plants, animals. Good luck!!

Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs
In accordance with the 2nd law of thermodynamics, there is a decrease in the amount of energy available to each succeeding organism in a food chain or web.

Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs
Ecological efficiency: percentage of useable energy transferred as biomass from one trophic level to the next.(2-40% range) Figure 3-19

Productivity of Producers: The Rate Is Crucial
Gross primary production (GPP) Rate at which an ecosystem’s producers convert solar energy into chemical energy as biomass. Figure 3-20

Gross primary productivity (grams of carbon per square meter)
Figure 3.20 Natural capital: gross primary productivity across the continental United States based on remote satellite data. The differences roughly correlate with variations in moisture and soil types. (NASA’s Earth Observatory) Gross primary productivity (grams of carbon per square meter) Fig. 3-20, p. 66

Net Primary Production (NPP)
NPP = GPP – R Rate at which producers use photosynthesis to store energy minus the rate at which they use some of this energy through respiration (R). Figure 3-21

and unavailable to consumers Respiration
Sun Photosynthesis Energy lost and unavailable to consumers Respiration Gross primary production Net primary production (energy available to consumers) Figure 3.21 Natural capital: distinction between gross primary productivity and net primary productivity. A plant uses some of its gross primary productivity to survive through respiration. The remaining energy is available to consumers. Growth and reproduction Fig. 3-21, p. 66

What are nature’s three most productive and three least productive systems?
Figure 3-22

Chemosynthesis: Some organisms such as deep ocean bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas .

Consumers: Eating and Recycling to Survive
Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their remains. Herbivores Primary consumers that eat producers Carnivores Secondary consumers eat primary consumers Third and higher level consumers: carnivores that eat carnivores. Omnivores Feed on both plant and animals.

Decomposers and Detrivores
Burying Beetles Video -- National Geographic Decomposers: Recycle nutrients in ecosystems. Detrivores: Insects or other scavengers that feed on wastes or dead bodies. Generally scavengers are considered to be larger animals and detrivores are insects. Figure 3-13

Detrivores Decomposers Termite and carpenter ant work
Bark beetle engraving Carpenter ant galleries Long-horned beetle holes Dry rot fungus Wood reduced to powder Figure 3.13 Natural capital: various scavengers (detritivores) and decomposers (mostly fungi and bacteria) can “feed on” or digest parts of a log and eventually convert its complex organic chemicals into simpler inorganic nutrients that can be taken up by producers. Mushroom Time progression Powder broken down by decomposers into plant nutrients in soil Fig. 3-13, p. 61

Aerobic and Anaerobic Respiration: Getting Energy for Survival
Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy they need. This is usually done through aerobic respiration. The opposite of photosynthesis

Aerobic and Anaerobic Respiration: Getting Energy for Survival
Anaerobic respiration or fermentation: Some decomposers get energy by breaking down glucose (or other organic compounds) in the absence of oxygen. The end products vary based on the chemical reaction: Methane gas Ethyl alcohol Acetic acid Hydrogen sulfide

Two Secrets of Survival: Energy Flow and Matter Recycle
An ecosystem survives by a combination of energy flow and matter recycling. Figure 3-14

Biodiversity Loss and Species Extinction: Remember HIPPO
H for habitat destruction and degradation I for invasive species P for pollution P for human population growth O for overexploitation

Why???????

But what’s wrong with corn?” you might ask.
In a sense, nothing. In its whole form, corn is a cheap, filling source of starch and vitamins, and its obvious versatility makes it an important culinary staple. As it has been, for thousands of years. But only the tiniest fraction of our corn supply ends up boiled and buttered, or even converted to cornmeal. Given current farm bills and modern commodity agriculture, large-scale corn producers receive government subsidies—to the tune of 4 billion dollars a year—making the crop ludicrously (and, in a sense, artificially) cheap. That creates the incentive to sell, sell, sell, in every possible form. And since we can only eat so much corn on the cob, that means conjuring all sorts of corn-based derivatives. So we end up with corn processed beyond recognition, into forms that eliminate virtually all of its nutritional content.

Of course then we also have URBAN DEVELOPMENT

Why Should We Care About Biodiversity?
The health of a species reflects the health of an ecosystem which reflects of the health of the biosphere which is where humans live. “We are all connected”

Some species are so critical to the functioning of an
Ecosystem that they are called KEYSTONE SPECIES 1800’s sea otters hunted for fur Sea otters eat sea urchins, so with no predators, they began to multiply Fish begin to decline because Kelp are the breeding grounds for fish, this affected fishermen's catches. Sea urchins eat kelp, which then began to disappear California Sea Otter Tax Check-Off - Defenders of Wildlife

Flower power. Rosy periwinkle has given rise to drugs used to treat childhood leukemia and Hodgkin's disease.

Spider find. A compound in the venom of black widow spiders found in the Negev Desert in Israel may hold promise for treating strokes

It had to be yew. The drug Taxol, made from the bark of the Pacific yew, helps fight breast and ovarian cancers.

Food Webs Trophic levels are interconnected within a more complicated food web. Figure 3-18

Animation: Prairie Food Web
PLAY ANIMATION

Which of the following ecosystems has the highest average net primary productivity?
a. agricultural land b. open ocean c. temperate forest d. swamps and marshes e. lakes and streams Which of the following ecosystems has the lowest level of kilocalories per square meter per year? a. open ocean b. tropical rain forest c. agricultural land d. lakes and streams e. temperate forest

Ecosystem egg 1. What does the light reaction in photosynthesis produce? 2. Which law of thermodynamics accounts for the 10% rule? 3. Which terrestrial ecosystem has the highest GPP? 4. which aquatic ecosystem has the highest GPP?

Ecosystem egg continued
5. which aquatic ecosystem has the lowest GPP? 6. which terrestrial ecosystem has the lowest GPP? 7. Primary productivity would be greatest at which line of latitude? 8. Primary productivity would be greatest in which ocean realm of the Arctic ocean

Eco egg continued 9. What % of sunlight reaching the earth is actually used by plants for the process of photosynthesis? 10. What is likely the biggest threat to biodiversity on this planet? 11. Good ozone can be found where? 12. Bad ozone is caused by what? 13. Good ozone does what for the planet?

Eco egg continued 14. Which greenhouse gas is a product of anaerobic respiration? 15. Aside from habitat destruction, what is the other main cause of loss of biodiversity on the planet? 16. The phenomenon causing global warming occurs in which layer of the atmosphere? 17. What do humans do that is messing up or breaking down the ozone layer?

Eco egg cont 18. Give one example of an abiotic factor and one example of a biotic factor in an ecosystem. 19. What is the Edge effect and how does is influence biodiversity? 20. What is the formula for NPP? 21. What is an example of a keystone species 22. give the formula for cellular respiration

Eco egg continued 23. Please give an example of an aquatic tertiary consumer? (2 pts) 24. What’s the difference between a detrivore and a scavenger and a decomposer (3pts) 25. what is the MOST limiting factor in the Arctic Ocean? (1pt) 26. what is the ultimate source of energy for life on earth? (1 pt) 27. Name a primary consumer (1 pt)

Eco egg cont 28 What is a likely result of lack of genetic diversity in a food crop like corn? (2pts) 29. What is the process called in which organisms make food from hydrogen sulfide gas coming from hydrothermal vents? (2 pts) 30. What is the approximate efficiency of energy transfer going from one trophic level to the next? (2pts)

Last question…..not on the test but worth a buncha points
Describe in detail the “corn controversy” relate it to the concepts covered in this class. (5 pts)

SOIL: A RENEWABLE RESOURCE
Soil is a slowly renewed resource that provides most of the nutrients needed for plant growth and also helps purify water. Soil formation begins when bedrock is broken down by physical, chemical and biological processes called weathering. Mature soils, or soils that have developed over a long time are arranged in a series of horizontal layers called soil horizons.

SOIL: A RENEWABLE RESOURCE
Figure 3-23

Wood sorrel Oak tree Organic debris builds up Lords and ladies
Dog violet Rock fragments Grasses and small shrubs Earthworm Millipede Fern Moss and lichen Honey fungus O horizon Mole Leaf litter A horizon Topsoil B horizon Bedrock Subsoil Immature soil Regolith Young soil C horizon Figure 3.23 Natural capital: soil formation and generalized soil profile. Horizons, or layers, vary in number, composition, and thickness, depending on the type of soil. (Used by permission of Macmillan Publishing Company from Derek Elsom, Earth, New York: Macmillan, Copyright © 1992 by Marshall Editions Developments Limited) Pseudoscorpion Mite Parent material Nematode Root system Actinomycetes Red Earth Mite Fungus Mature soil Bacteria Springtail Fig. 3-23, p. 68

Layers in Mature Soils Infiltration: the downward movement of water through soil. Leaching: dissolving of minerals and organic matter in upper layers carrying them to lower layers. The soil type determines the degree of infiltration and leaching.

Soil Profiles of the Principal Terrestrial Soil Types
Figure 3-24

Desert Soil (hot, dry climate) Grassland Soil (semiarid climate)
Mosaic of closely packed pebbles, boulders Weak humus-mineral mixture Alkaline, dark, and rich in humus Dry, brown to reddish-brown with variable accumulations of clay, calcium and carbonate, and soluble salts Figure 3.24 Natural capital: soil profiles of the principal soil types typically found in five types of terrestrial ecosystems. Clay, calcium compounds Desert Soil (hot, dry climate) Grassland Soil (semiarid climate) Fig. 3-24a, p. 69

Tropical Rain Forest Soil (humid, tropical climate)
Acidic light-colored humus Figure 3.24 Natural capital: soil profiles of the principal soil types typically found in five types of terrestrial ecosystems. Iron and aluminum compounds mixed with clay Tropical Rain Forest Soil (humid, tropical climate) Fig. 3-24b, p. 69

Deciduous Forest Soil (humid, mild climate)
Forest litter leaf mold Humus-mineral mixture Light, grayish-brown, silt loam Figure 3.24 Natural capital: soil profiles of the principal soil types typically found in five types of terrestrial ecosystems. Dark brown firm clay Deciduous Forest Soil (humid, mild climate) Fig. 3-24b, p. 69

Coniferous Forest Soil
Acid litter and humus Light-colored and acidic Figure 3.24 Natural capital: soil profiles of the principal soil types typically found in five types of terrestrial ecosystems. Humus and iron and aluminum compounds Coniferous Forest Soil (humid, cold climate) Fig. 3-24b, p. 69

Leaf mold, a humus-mineral mixture, and silty loam are indicative of
a. coniferous forest soil. b. deciduous forest soil. c. tropical forest soil. d. grassland soil. e. desert soil. Soil comprised of litter and humus, and is acidic due to the accumulation of needles a. desert soil b. grassland soil tropical rainforest soil coniferous forest soil deciduous forest soil

Soils found in mid-latitude grasslands would be most accurately described as having
a high acid content with little organic matter a deep layer of humus and decayed plant material a layer of permafrost right below the O-horizon d. a high content of iron oxides and very little moisture e. a small amount of nutrients but an abundant decomposer food web

Some Soil Properties Soils vary in the size of the particles they contain, the amount of space between these particles, and how rapidly water flows through them. Figure 3-25

0.05–2 mm diameter 0.002–0.05 mm diameter less than 0.002 mm Diameter
Sand Silt Clay 0.05–2 mm diameter 0.002–0.05 mm diameter less than mm Diameter Water Water Figure 3.25 Natural capital: the size, shape, and degree of clumping of soil particles determine the number and volume of spaces for air and water within a soil. Soils with more pore spaces (left) contain more air and are more permeable to water than soils with fewer pores (right). High permeability Low permeability Fig. 3-25, p. 70

The porosity of a soil is defined to be the volume of the pores as a percentage of the total volume of soil. Sandy soils have porosities ranging from 30 to 40 percent, compared with 40 to 60 percent for clays. Porosity provides a measure of the amount of water that each soil can retain. Clay soils have a higher porosity and can hold more water. (smaller pores, but more of them)

More on soils If a soil is acidic, that can be a problem, because when the pH is low, this causes the release or “freeing up” of aluminum ions. Then the soil tends to want to uptake aluminum rather than the nutrients needed So to recap, acidic soil releases aluminum and this can burn the plants leaves and kill the plant

Give a brief description of what pH is…………
How can this problem be solved?????????????

Well, if your soil is too acidic (low pH) one solution would be to add lime or ground-up limestone to your soil, this will bring up the pH. Adding sulfur can bring the pH down.

Eutrophication!!!!!! Happens when excess nitrogen or phosphorus from fertilizers or animal manure runs off into water ways Causes the excess growth of algae The algae eventually dies and decomposes The decomposing bacteria take dissolved oxygen out of the water Aquatic life (like fishies) dies off (a perfect example of this is the Salton Sea or the Gulf of Mexico)

Legumes as nitrogen fixers
Legumes (soybeans, alfalfa, clover) have specialized bacteria on their root nodules that “fix” nitrogen from the air and put it into the soil So, they work perfectly as “cover crops” to renew soil nitrogen on plots of land that are “resting” in between plantings

MATTER CYCLING IN ECOSYSTEMS
Nutrient Cycles: Global Recycling Global Cycles recycle nutrients through the earth’s air, land, water, and living organisms. Nutrients are the elements and compounds that organisms need to live, grow, and reproduce. Biogeochemical cycles move these substances through air, water, soil, rock and living organisms.

The Water Cycle Figure 3-26

Water’ Unique Properties
There are strong forces of attraction between molecules of water. Water exists as a liquid over a wide temperature range. Liquid water changes temperature slowly. It takes a large amount of energy for water to evaporate. Liquid water can dissolve a variety of compounds. Water expands when it freezes.

Effects of Human Activities on Water Cycle
We alter the water cycle by: Withdrawing large amounts of freshwater. Clearing vegetation and eroding soils. Polluting surface and underground water. Contributing to climate change.

The Carbon Cycle: Part of Nature’s Thermostat
Figure 3-27

Figure 3.27 Natural capital: simplified model of the global carbon cycle. Carbon moves through both marine ecosystems (left side) and terrestrial ecosystems (right side). Carbon reservoirs are shown as boxes; processes that change one form of carbon to another are shown in unboxed print. QUESTION: What are three ways in which your lifestyle directly or indirectly affects the carbon cycle? (From Cecie Starr, Biology: Concepts and Applications, 4th ed., Pacific Grove, Calif.: Brooks/Cole, © 2000) Fig. 3-27, pp

Effects of Human Activities on Carbon Cycle
We alter the carbon cycle by adding excess CO2 to the atmosphere through: Burning fossil fuels. Clearing vegetation faster than it is replaced. Figure 3-28

(billion metric tons of carbon equivalent)
High projection Low projection (billion metric tons of carbon equivalent) CO2 emissions from fossil fuels Figure 3.28 Natural capital degradation: human interference in the global carbon cycle from carbon dioxide emissions when fossil fuels are burned and forests are cleared, 1850 to 2006 and projections to 2030 (dashed lines). (Data from UN Environment Programme, British Petroleum, International Energy Agency, and U.S. Department of Energy) Year Fig. 3-28, p. 74

The Nitrogen Cycle: Bacteria in Action
Figure 3-29

Excretion, death, decomposition
Gaseous nitrogen (N2) in atmosphere Food webs on land Nitrogen fixation Fertilizers Uptake by autotrophs Figure 3.29 Natural capital: simplified model of the nitrogen cycle in a terrestrial ecosystem. Nitrogen reservoirs are shown as boxes; processes changing one form of nitrogen to another are shown in unboxed print. QUESTION: What are three ways in which your lifestyle directly or indirectly affects the nitrogen cycle? (Adapted from Cecie Starr, Biology: Today and Tomorrow, Brooks/Cole © 2005) Loss by denitrification Excretion, death, decomposition Uptake by autotrophs Ammonia, ammonium in soil Nitrogen-rich wastes, remains in soil Nitrate in soil Nitrification Ammonification Loss by leaching Loss by leaching Nitrite in soil Nitrification Fig. 3-29, p. 75

Effects of Human Activities on the Nitrogen Cycle
We alter the nitrogen cycle by: Adding gases that contribute to acid rain. Adding nitrous oxide to the atmosphere through farming practices which can warm the atmosphere and deplete ozone. Contaminating ground water from nitrate ions in inorganic fertilizers. Releasing nitrogen into the troposphere through deforestation.

Effects of Human Activities on the Nitrogen Cycle
Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined. Figure 3-30

Global nitrogen (N) fixation
Nitrogen fixation by natural processes Global nitrogen (N) fixation (trillion grams) Figure 3.30 Natural capital degradation: human interference in the global nitrogen cycle. Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined. (Data from UN Environment Programme, UN Food and Agriculture Organization, and U.S. Department of Agriculture) Nitrogen fixation by human processes Year Fig. 3-30, p. 76

The Phosphorous Cycle Figure 3-31

mining Fertilizer excretion Guano agriculture weathering uptake by
autotrophs uptake by autotrophs leaching, runoff Marine Food Webs Dissolved in Ocean Water Dissolved in Soil Water, Lakes, Rivers Land Food Webs death, decomposition death, decomposition Figure 3.31 Natural capital: simplified model of the phosphorus cycle. Phosphorus reservoirs are shown as boxes; processes that change one form of phosphorus to another are shown in unboxed print. QUESTION: What are three ways in which your lifestyle directly or indirectly affects the phosphorus cycle? (From Cecie Starr and Ralph Taggart, Biology: The Unity and Diversity of Life, 9th ed., Belmont, Calif.: Wadsworth © 2001) weathering sedimentation settling out uplifting over geologic time Marine Sediments Rocks Fig. 3-31, p. 77

Effects of Human Activities on the Phosphorous Cycle
We remove large amounts of phosphate from the earth to make fertilizer. We reduce phosphorous in tropical soils by clearing forests. We add excess phosphates to aquatic systems from runoff of animal wastes and fertilizers.

The Sulfur Cycle Figure 3-32

Acidic fog and precipitation
Water Sulfur trioxide Sulfuric acid Acidic fog and precipitation Ammonia Ammonium sulfate Oxygen Sulfur dioxide Hydrogen sulfide Plants Dimethyl sulfide Volcano Industries Animals Ocean Figure 3.32 Natural capital: simplified model of the sulfur cycle. The movement of sulfur compounds in living organisms is shown in green, blue in aquatic systems, and orange in the atmosphere. QUESTION: What are three ways in which your lifestyle directly or indirectly affects the sulfur cycle? Sulfate salts Metallic sulfide deposits Decaying matter Sulfur Hydrogen sulfide Fig. 3-32, p. 78

Effects of Human Activities on the Sulfur Cycle
We add sulfur dioxide to the atmosphere by: Burning coal and oil Refining sulfur containing petroleum. Convert sulfur-containing metallic ores into free metals such as copper, lead, and zinc releasing sulfur dioxide into the environment. cycleactivity 2007.pdf

Ecosystems: What Are They and How Do They Work?

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