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Ecosystems: Components, Energy Flow, and Matter Cycling

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1 Ecosystems: Components, Energy Flow, and Matter Cycling
Chapter 3 The Earth as a System Ecosystems Food Webs and Energy Flow Productivity in Ecosystems Cycling of Matter

2 U Choose Describe one specific ecosystem. What are its major components; name some biotic and abiotic factors that affect it. Cite one population and how it lives within its Law of Tolerance. Draw, label and define all terms related to the Law of tolerance. How is energy used in an ecosystem? What happens to it as it is used (or not used)? What are the tyes of energy and how is cellular respiration and photosynthesis related to the flow of energy? A bumper sticker reads, “Have you thanked a green plant today?” Give two reasons for appreciating a green plant. Then trace the sources of the materials that make up the bumper sticker, and decide whether the sticker itself is a sound application of the slogan.

3 Key Concepts Basic ecological principles Major components of ecosystems Matter cycles and energy flow Ecosystem studies Ecological services

4 Natural Capitol: How do humans affect these?
Biodiversity Genetic Diversity of organisms Population dispersal Ecosystem Health Energy Flow Nutrient Cycling?

5 Organism: any life form Types of Cells
Nucleus Eukaryotic Cells: have organelles, nucleus, multicellular, derived. Prokaryotic Cells : no nucleus, ancient, single celled

6 The Nature of Ecology Ecology- the study of how organisms interact with each other and their abiotic componants of their environment Oikos: house logos: study of Organisms- any life form Cells- the basic unit of life; come in two flavors Prokaryote- cells with no defined nucleus; bacteria Eukaryote- cells with a defined nucleus that contains DNA; most familiar organisms and multicellular organisms Species- groups of organisms that share similar DNA; look similar, have similar behavior, etc. Asexual Reproduction-cellular division to produce identical offspring (clones) Sexual Reproduction- production of offspring by combining sex cells (gametes) to create progeny that are a combination of each of the parents’ characteristics

7 Levels of organization within an organism
Atom Molecule Cell Tissue Organ Systems

8 Levels of organization out of organism
Biosphere Biomes Ecosystems Communities Populations Organism Chpt4.1

9

10 What are the Characteristics of Life?
Chapter What is Life? What are the Characteristics of Life?

11 Populations Population- all of the organisms within a species that interact in a specific area and at a specific time Genetic Diversity- similar but different due to DNA Affected by: Size Age distribution Density Genetic composition health

12 Ecosystems Ecology An ecosystem is a self-sustaining community of organisms and the non-living environment with which they interact. And range in size. An ecosystem is the fundamental unit of ecology.

13 What about biodiversity?

14 BIODIVERSITY The many measures of biodiversity:
The variety or chemicial processes, genetic material, species diversity, and ecosystems found on earth.

15 Biodiversity Leads to Better productivity…
Organisms are Genetically adapted to survive more diverse conditions Have more stable populations because their range of tolerance is wider

16 Why worry about biodiversity and stability?

17 BIODIVERSITY AND STABILITY
Because this understanding is essential for knowing how many species and what types can be lost before a community collapses entirely

18 Biodiversity is Being Lost Rapidly Through Extinction
How rapid is the current rate of extinction? The number’s hard to pin down, but generally accepted estimates put it at times the rate before extensive human–induced environmental modifications. For example, in the U.S. ~ 225 vascular plant species have become extinct in the past 50 years and about 650 of the remaining 20,000 species are threatened.

19 Dire News Not all agree that we’re seeing a mass extinction, but it’s clear species loss has accelerated sharply above background.

20 Biodiversity Varies Naturally
There is a trend towards more species in warmer, wetter areas and fewer in colder and drier areas. Warmer Moister areas: Rainforest Dryer Areas: Deserts - Taigas Numbers of bird species occupying areas of North America.

21 There are Biodiversity “Hotspots”
Biodiversity hotspots for tropical rain forest and chaparral ecosystems. Less than 1% of Earth’s surface supports 20% of known plant species and probably a greater portion of animal species. Biodiversity hotspots are significant for conservation plans.

22 Species Distributions Are Now Changing in Response to Global Warming
This map shows projections, but many dramatic shifts in species distribution have already been documented.

23 Biodiversity Index Formula shows health of ecosystem in question
# of specific species found ______________________ = BI # of species found What is the biodiversity Index of trees at JCHS? What contributes to the Index here?

24 Biodiversity Index Example
# of black spiders # of all spider species = BI

25 Can you match these? Functional Diversity Genetic Diversity
Ecological Diversity Species Diversity Differing DNA material within a single species Variety or terrestrial/ aquatic ecosystems in one area Number of species present in different habitats Biological and Chemical processes needed for survival of species, communities,ecosystems Lets see…….

26 Biodiversity Species Diversity- the variety among the species or distinct types of living organisms found in different habitats of the planet Ecological Diversity- the variety of different biomes around the world; all biological communities Functional Diversity- biological and chemical processes or functions such as energy flow and matter cycling needed for the survival of species and biological communities

27 Species Diversity Types
Species Evenness – A few species but an even number of members per species How even is the diversity? Species Richness A large number of species with only a few members of each species present. This is related to species biodiversity How rich are the species in your area? IF: Species A = 56 members Species B = 55 members Species C = 52 Then: species evenness is good but diversity is low! Rainforest, coral reef , deep sea, large tropical lakes have high species diversity but low species evenness (few members in each)

28 NICHE: Realized Niche Fundamental Niche

29 Principles of Ecological Factors
Range of Tolerance- any variation in the physical or chemical environment that an organism can withstand before it is killed/harmed The Law of Tolerance states that the existence, abundance, and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species. Fig p. 73; Refer to Fig p. 73

30 The Earth’s Life-Support Systems

31 Biosphere:5 miles up and 5 miles down

32 Productivity of Producers
Ecosystems use solar energy to produce and use biomass at differing rates

33 GPP and NPP GPP Gross Primary Production: Rate at which producers convert solar energy to biomass NPP(Net Primary Productivity): The amount of biomass left after producers have used what they need for cellular functions such as cellular respiration.

34 Ecosystem examples High NPP Low NPP estuaries Open ocean
High NPP Low NPP estuaries Open ocean Swamps and marshes Tundra Tropical rain forests Desert 

35 Net Primary Productivity
The earth’s net primary productivity is the upper limit determining the planet’s carrying capacity for all consumer species. Our Share of Earth’s NPP 1)  We use, waste or destroy about 27% of earth’s NPP 2)  We use, waste or destroy about 40% of the NPP of terrestrial ecosystems Produces are the source of diversity

36 Carrying Capacity

37 Sustaining Life of Earth
One-Way Energy Flow: All energy on earth comes from the sun and eventually escapes earth. It perpetuates the cycles as well.

38 There are two types of energy
High quality energy: Low quality energy: is concentrated and has ability to do useful work. Sun, electricity ,coal, oil , gasoline, nucleii of uranium Moves through organisms by feeding interactions Becomes low quality energy and radiates as heat is dispersed has little ability to do useful work. Low temp heat. Can keep each other warm in the cold for short periods of time - Is typically given off after a reaction of high quality energy - Escapes into atmosphere and space

39 The Sun also initiates all biogeochemical cycles with its heat contributing to the abiotic factors of an ecosystem. Nutrients are cycled through the biosphere for use by food chains, webs, and the biosphere itself in many forms Carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus are main elements

40 The Carbon Cycle Understanding of the carbon cycle is critical for global climate change, yet it remains incomplete.

41 The Carbon and oxygen Cycles: Carbon and Oxygen
The continuous movement of carbon and oxygen from non-living into living organisms CO2 in atmosphere build organic molecules Plants use CO2 to produce O2 This exchange of CO2 for O2 is called Respiration (cellular respiration) Combustion or burning releases carbon Burning trees, fossil fuels: oil and coal

42 Life On a Changing Planet
Science (2006) 311:1698

43 Human impacts on the Carbon Cycle
1.  Clear trees and other plants that absorb carbon dioxide by photosynthesis destroying the carbon sinks .Sinks are areas of storage for any element. 2.   Burning of fossil fuels and wood which add large amounts of carbon dioxide to the atmosphere contributing to global warming. 3. Results in loss of biodiversity,collapse of ecosystems, change in species distribution, degradation and collapse of human societies

44 Example of such activities are the build-up of Greenhouse Gases contributing to Global Warming. Which is when gases absorb heat, the heat is trapped, the earth warms.

45 A Warming World Graph shows as human population numbers have increased so have temperatures increased. It also shows a correlation o=to the amount of CO2 that had been available .

46 The Nitrogen Cycle Note the key role of mutualism between nitrogen-fixing bacteria and their plant hosts. Nitrogen fixation is the ‘fixing of unuseable nitrogen into useable nitrogen for plants

47 Root nodules on Cassia fasciculata

48 DISSOLVED IN OCEAN WATER DISSOLVED IN SOILWATER, LAKES, RIVERS
mining FERTILIZER excretion GUANO agriculture weathering uptake by autotrophs uptake by autotrophs MARINE FOOD WEBS DISSOLVED IN OCEAN WATER weathering DISSOLVED IN SOILWATER, LAKES, RIVERS LAND FOOD WEBS death, decomposition death, decomposition settling out sedimentation leaching, runoff uplifting over geolgic time ROCKS MARINE SEDIMENTS Fig. 4.32, p. 96

49 Nitrogen Cycle (atmospheric cycle)
GASEOUS NITROGEN (N2) IN ATMOSPHERE NITROGEN FIXATION by industry for agriculture FOOD WEBS ON LAND uptake by autotrophs excretion, death, decomposition uptake by autotrophs FERTILIZERS NITROGEN FIXATION bacteria convert to ammonia (NH3+) ; this dissolves to form ammonium (NH4+) NITROGENOUS WASTES, REMAINS IN SOIL NO3- IN SOIL DENTRIFICATION by bacteria AMMONIFICATION bacteria, fungi convert the residues to NH3 , this dissolves to form NH4+ 2. NITRIFICATION bacteria convert NO2- to nitrate (NO3-) NH3, NH4+ IN SOIL 1. NITRIFICATION bacteria convert NH4+ to nitrate (NO2-) loss by leaching NO2- IN SOIL loss by leaching  Nitrogen Cycle (atmospheric cycle) Fig. 4.30, p. 94

50 Human Impact on the Nitrogen Cycle
1)      Adding Nitric Oxide gas to the atmosphere when we burn fuel yields Acid Precipitation 2)      Adding Nitrous Oxide Gas to the atmosphere through anaerobic bacteria’s action on livestock waste and commercial waste leads to ozone depletion and the greenhouse effect. 3)      Removing nitrogen from earth’s crust and soil through mining activities leaves plants devastated. 4)      Removing nitrogen from topsoil by over farming leaves soil without nitrogen a.       harvesting nitrogen rich crops b.      irrigating crops c.       burning or clearing grasslands and forests before planting crops 5)     

51 Human Impact continued:
5)Adding nitrogen to aquatic through run-off ecosystems - depletes dissolved oxygen killing some aerobic aquatic organisms a.       agricultural runoff b.      municipal sewage

52 A real time example of excessive amounts of Nitrogen Fertilizer Harming an Ecosystems
A seasonal “dead zone” where virtually all marine life is killed stretches off the Mississippi Delta. Why? About 1.5 million metric tons of nitrogen from fertilizer runoff promotes algal and bacterial blooms that deplete oxygen from the water.

53 The Water Cycle Only about 40% of precipitation on land comes from water evaporated over oceans; roughly 60% comes from transpiration of water through plants.

54 Surface runoff (rapid)
Condensation Rain clouds Transpiration from plants Precipitation Transpiration Precipitation Precipitation to ocean Evaporation Evaporation From ocean Surface runoff (rapid) Runoff Infiltration and Percolation Surface runoff (rapid) Groundwater movement (slow) Ocean storage Groundwater movement (slow) Fig. 4.28, p. 90

55 The Percentage of Available Global Freshwater is Very Small

56 Freshwater Is a Precious and Often Scarce Resource

57 Human Activities and the Hydrologic Cycle
1.      Over-consumption of surface and groundwater lead to groundwater depletion and saltwater intrusion into groundwater supplies. 2.  Clearing vegetation from land leads to increased runoff, decreased infiltration to replenish groundwater, increases risk of floods, and accelerates soil erosion and landslides. 3.  Adding nutrients and pollutants to water diminishes the ability of humans and other species to use it and interferes with natural purification. 

58 The Phosphorus Cycle

59 Phosphorus Cycle: Phosphorus
An important ingredient in DNA and RNA and all proteins Flows in organism in different chemical forms into the surroundings and back into organisms Doesn’t enter atmosphere In soil and rock. Dissolves and is used by plants Plants are eaten by animals, animals die, cycle begins again

60 Phosphorus Cycle (sedimentary cycle)
Human impacts on the Phosphorus Cycle  1. Mining large quantities of phosphate rock depletes resources a.   inorganic fertilizers b..  detergents 2. Reducing available phosphate in tropical forests through slash and burn agriculture depletes it. a.  phosphate is washed away by heavy rains. 3.  Adding excess phosphate to aquatic ecosystems depletes dissolved oxygen and disrupts aquatic ecosystems a.   runoff from animal wastes b.   runoff of commercial inorganic fertilizers from cropland c.   discharge of municipal sewage

61 (atmospheric cycle and land)
Hydrogen sulfide (H2S) + Oxygen (O2) Atmosphere Sulfur dioxide (SO2) and Sulfur trioxide (SO3) Sulfur Cycle (atmospheric cycle and land) + Water (H2O) Dimethl (DMS) Industries Volcanoes and hot springs Sulfuric acid (H2SO4) + Ammonia (NH2) Oceans Ammonium sulfate [(NH4)2SO4] Fog and precipitation (rain, snow) Animals Plants Sulfate salts (SO42-) Aerobic conditions in soil and water Decaying organisms Sulfur (S) Anaerobic conditions in soil and water Fig. 4.33, p. 97 Hydrogen sulfide (H2S)

62 Sulfur Cycle (atmospheric cycle) (figure 4-33)
Human Impacts on the Sulfur Cycle 1. Burning sulfur containing coal and oil to produce electric power a.  produces sulfur dioxide>>acid rain 2.  refining petroleum>>sulfur dioxide>>acid rain 3.  smelting to convert sulfur compounds of metallic minerals into free metals such as copper, lead and zinc. a.  produces sulfur dioxide and trioxide>>acid rain

63 We’re in the Driver’s Seat - Human Activities Dominate Many Biogeochemical Cycles

64 Sustaining Life of Earth
One-Way Energy Flow: All energy on earth comes from the sun and eventually escapes earth. Perpetuates the cycles.

65 Photosynthesis Chemical reaction where green plants use water & carbon dioxide to store the sun’s energy as glucose 6CO2 + 6H2O C6H12O6 + 6O2

66 The Sun is the generator of the flow of energy as well.
Cellular Respiration is just the opposite formula Glucose + Oxygen  Water and Carbon Dioxide

67 Cellular Respiration 6O2 + C6H12O6 --> 6H2O + 6CO2
process of cells breaking down food ,glucose, made by plants, to make ATP. ATP is cell energy cells use to do cellular functions such as Metabolism Making new cells (Mitosis) Growth and development Reproduction All living organisms respirator Can you think of any?

68 Inputs are: Outputs are:

69 Respiration can be accomplished in two ways by different organisms
Aerobic Respiration-the use of oxygen to produce energy Glucose + Oxygen --> Carbon Dioxide + Water + Energy C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O + Energy Anaerobic Respiration- (a.k.a. fermentation) a form of cellular respiration in the absence of Oxygen End products: methane; ethyl alcohol; acetic acid; or hydrogen sulfide, lactic acid Production of Energy: different types of energy production Chemosynthesis (typically bacteria)-The conversion of simple compounds into more complex nutrient compounds without the aide of sunlight

70 The Source of Energy Chpt 4.2

71 Producers (autotrophs)
The Biotic Components of Ecosystems are also supported by the suns energy Producers (autotrophs) Consumers (heterotrophs) Decomposers Fig p. 75

72 Organisms that can make glucose during photosynthesis are called PRODUCERS or AUTOTROPHS.

73 Organisms that cannot make their own energy are called CONSUMERS or HETEROTROPHS.

74 Consumers that Eat other Consumers
Secondary or 2nd order consumers May be a carnivore or omnivore May be a predator May be a scavenger

75 Consumers that eat consumers that already ate a consumer:
Tertiary or 3rd order consumer May be a carnivore or omnivore May be a predator May be a scavenger

76 Cast of Food Web Characters
Tertiary Consumers – Animals that eat animals that eat animals Secondary Consumers – Animals that eat animals that eat plants Primary Consumers – Animals that eat plants Primary Producers – Plants and Phytoplankton: organisms using the sun for energy  Students have a copy of this pyramid on their worksheet and are to identify primary producers, primary consumers, secondary consumers, and tertiary consumers.

77 These levels of organization are called TROPHIC Levels

78 Primary consumer (herbivore)
Trophic Levels: “steps” in a food chain moving from producers to different levels of consumers. Producer Primary consumer (herbivore) Secondary consumer (carnivore) Tertiary consumer Omnivore Detritivores and scavengers Decomposers

79 Connections:Food Webs show the transfer of energy in an ecosystem

80 Connections: Food Chains, a thread of a food web, also show energy Flow in Ecosystems
Fig p. 77; Refer to Fig p. 78

81 Ecological Pyramids have many jobs
Energy Flow Pyramid Fig p. 79 Ecological efficiency Pyramid of biomass Pyramid of numbers Pyramid of bioaccumulation

82 THE ECOLOGICAL PYRAMIDS represent
Energy Flow pyramid: Trophic Levels that depict a food chain or web delivering chemical energy Ecological Efficiency: Percentage of useable energy transferred as BIOMASS limits trophic levels Pyramid of Numbers: The ten percent rule – only 10 percent of energy is passed on to the next level due to metabolism of organism using it Pyramid Biomass: The dry weight of all organic matter at that trophic level Pyramid of Bioaccumulation: The increase of the concentration of toxins as it passes through levels of the food web.

83 How is Energy Moved and Utilized in Ecosystems?

84 TROPHIC LEVELS AND ENERGY TRANSFER or MOVEMENT
90% OF ENERGY IS USED AT EACH Level for cell functions at that level and some is lost as heat. That leaves 10% to be transferred to the next level.

85 The pyramid of Numbers: Only a Fraction of the Energy Present in Organisms of One Trophic Level Is Captured by Organisms of the Next .10% 1.0% 10% 100% This limits the number of trophic levels.

86 Some of the energy moves into the atmosphere as heat.
Some energy in the primary consumer is STORED as Glucose or used by the consumer itself This energy is available for another consumer

87 Energy Pyramids Show Amount of available energy decreases for higher consumers Amount of available energy decreases down the food chain It takes a large number of producers to support a small number of primary consumers It takes a large number of primary consumers to support a small number of secondary consumers 87 87

88 Detritivores and Decomposers
All through the food pyramid are Detritivores and decomposers. They are Consumers that break down dead organic materials They break down and contribute to the biogeochemical cycles.

89 Celebrating Rot and Decay - Detritivores
Energy isn’t transferred only upwards between trophic levels. Detritovores use the energy available in dead organisms and allow recycling of essential nutrients in ecosystems.

90 Do you see the energy flow and cycles connection?

91 What is Biomass ? The accumulation of dry organic matter that contributes to a tropic level . It is based on the second law of Thermodynamics: Matter is never destroyed or created, it can be transferred. 1.Which level has the most biomass? 2.Does Biomass change as climates differ? 3.Does more biomass produce more life? Since biomass accumulates at a rate in direct response to solar energy then Yes to 2 and 3!

92 Do different ecosystems have different amounts of available energy or biomass?
Abandoned Field Ocean Tertiary consumers Secondary consumers Primary consumers Producers Fig. 4.22, p. 86

93 Grassland (summer) Temperate Forest (summer) Tertiary consumers
Secondary consumers Primary consumers Producers Fig. 4.23, p. 86

94 Bioaccumulacation and biomagnification Why is food web knowledge important for understanding the impact of DDT on ospreys and eagles?

95 Bioaccumulation = the accumulation of a contaminant or toxin in or on an organism from all sources (e.g., food, water, air). Compounds accumulate in living things any time they are taken up and stored faster than they are broken down (metabolized) or excreted. Chemicals that are soluble in fat, like DDE, particularly tend to bioaccumulate compared to those soluble in water. Chemicals that are soluble water are removed from the body in urine, whereas those soluble in fat, do not have a means to leave the body and remain in tissue.

96 Biomagnification = the increase in concentration of toxin as it passes through successive levels of the food web DDT accumulates at higher levels in organisms that are higher in the food chain

97 Biomagnification of a DDT in Aquatic Environment
Level Amount of DDT in Tissue Tertiary Consumer µg/g ww (fish eating birds) Secondary Consumers µg/g ww (large fish) This is an example of actual concentrations of DDT as it passes through the heron food chain. It is important that the students notice the units in which DDT is measured and to become familiar with the relative amount of DDT that accumulates in organisms of different trophic levels. Students will also be given another example using osprey to demonstrate this point. There are several factors that contribute to the problem of bioaccumulation and biomagnification in aquatic environments. When DDT is applied it runs off into water and collects in lakes, streams, wetlands and other bodies of water. Fish are then exposed to DDT through consumption of organic debris on the floor of a water body and/or through their gills when it is suspended in water. Thus, water dwelling creatures are at higher risk of bioaccumulating DDE. Primary Consumers (small fish) µg/g ww Primary Producers (algae and aquatic plants) 0.04 µg/g ww

98 Osprey Food Web DDT Concentration Osprey 3-76 µg/g ww Large Mouth Bass
Osprey are at the top of the aquatic food chain, and are thus exposed to many pollutants found in the environment. Toxic chemicals are present in water, air, sediments, and aquatic biota throughout osprey breeding and wintering ranges. Many of these contaminants bioconcentrate from water passed through fish gills, and bioaccumulate in the fish from their food. The efficient transfer of chemicals from food to consumer through two or more trophic levels results in biomagnification, a systematic increase in tissue residue concentrations from one trophic level to another. USGS Osprey in Oregon and the Pacific Northwest. USGS FS  Students will be asked to fill in the food chain given here and the relative concentrations of DDE. µg/g ww Crayfish Plant material and algae 0.04 µg/g ww

99 High levels of DDT cause the female ospreys to lay eggs with thin eggshells. Thin eggshells have a greater chance of breaking, leading to embryo death. With high levels of DDT, female ospreys can also lay eggs that contain high enough concentration of DDT to prevent embryo development.  Students have fill-in-the-blank questions to answer questions about this slide. It is important that students understand that high levels of DDE result in female osprey to lay thin eggs with thin eggshells.

100 Ospreys and eagles are tertiary consumers Making them particularly vulnerable to DDT as Bioaccumulation and Biomagnification take effect  The students will be asked to write down the definitions to bioaccumulation and biomagnification. Both terms will be define in the upcoming slides.

101 All food makes its way to the tertiary consumer
After DDT is applied, some DDT volatizes (vaporizes), some remains on the plant, and some washes off the plant into the soil, eventually making its way to a stream, river, or lake. The DDT that remains on the leaves of plants may be ingested by primary consumers such as insects and rodents. DDT that has washed into a waterbody, remains in the sediment or is consumed by bottom-feeding organisms or absorbed by fish gills and skin. All food makes its way to the tertiary consumer After DDT is applied, some DDT residue remains on the plant material and some washes off the plant into the soil eventually making its way to a body of water. The DDT that remains on the leaves of plants is taken up by primary consumers such as insects and rodents. As for the DDT that has washed into a stream, river or lake, it enters the food chain through consumption by bottom-feeding fish or through absorption by fish gills and skin.

102

103 Make an Energy Pyramid Four sides and four levels!!!
Separate each level with pencil mark Color each level the same color all the way around! Make sure all sides line up with the other three sides meaning! 1st side are the Trophic Levels: Producers, Herbivores,Carnivores,Top Carnivores 2nd side is type is consumer or producer: do not forget there are primary,secondary, and tertiary consumers!! 3rd side is type of eater: Autotroph or Heterotroph 4th side is Amount of energy that is transferred to next level 100% 10% 1.0% and .10%

104 Species Types(6.1): Fill major niches in ecosystems
Native Species- Normally live and thrive in ecosystem Non native, invasive, alien species – have been introduced to a community either accidentally or purposefully. Crowd out, outcompete, have no predators

105 Indicator Species Biological smoke alarms
Fish, birds, amphibians, butterflies Indicate ecosystem health: pH, Habitat fragmentation, dissolved oxygen in water communities, pollution, reduction in stratospheric ozone, over hunting…

106 Keystone Species Have a huge effect on the species richness and evenness of an ecosystem. A keystone species disappears can lead to population crashes and extinction. Ex: Top predators, bees, dung beetles,

107 Foundation Species Species that play major roles in enhancing habitats in ways that benefit other species. Elephants push over tress clearing ground for grass to grow, accelerate cycling of nutrients

108 Ecosystem Concepts and Components
Biomes-areas with a consistent climate and with similar organisms Climate- long-term weather patterns in a given area Precipitation and Temperature Aquatic life zones- marine and freshwater portions of the biosphere

109

110 Terrestrial Ecosystems
Aquatic Life Zones • Light penetration Depth • Water currents • Dissolved nutrient concentrations (especially Nitrogen and Phosphorus) • Suspended solids • Salinity • Sunlight Climate -Temperature - Precipitation • Wind • Latitude • Altitude (topography) • Fire frequency • Soil Figure 4-13 Page 73

111 Ecosystem Boundaries: Ecotones
Ecotone- transitional zones between ecosystems where there are a mixture of species not found together in adjacent ecosystems

112 Principles of Ecological Factors
Abiotic Factors- all of the nonliving parts in an ecosystem Biotic Factors-all of the living factors in an ecosystem Range of Tolerance- any variation in the physical or chemical environment that an organism can withstand before it is killed/harmed Law of tolerance-the existence, abundance, and distribution of a species in a n ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species. Fig p. 73; Refer to Fig p. 73

113 Limiting factors terrestrial and aquatic
Terrestrial: Precipitation, temperature, available nutrients(too much or too little) Aquatic: temperature, sunlight, nutrient availability, dissolved oxygen, pH, salinity

114 Regulating Population Growth
Limiting Factors- a distinguishing chemical or physical factor that regulates the population growth of a species; more specific than any other factor Limiting Factor Principle- Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimum range of tolerance. Niche- an organisms functional role within an ecosystem; everything that affects the survival and reproduction of itself and others Range of tolerance; resources it utilizes (food, space); interaction with other biota and abiotic factors; its role in the food web/matter cycle

115 Adaptations Plant and animal adaptations respond to limiting factor by adapting in many ways. Foods they eat, niches, habitats, physiology, mating timing, how they keep warm, use water….

116 The Biotic Components of Ecosystems
Producers (autotrophs) Consumers (heterotrophs) Decomposers Fig p. 75

117 LIST NATURAL CAPITOL Major components of freshwater systems
Major components of ecosystem Major Biomes found along the 39th parallel of the US Solar capitol – flow of energy Cycling of crucial elements (matter) Genetic Diversity among individuals within a species

118 Ecosystem Services and Sustainability
Fig p. 92

119 An Uncertain Future? Of course …
…. but that’s not to say there’s no hope.

120 Altered by Human Activity
63% Not used by Humans 3% Used Directly 8% Lost or Degrades Land 16% Altered by Human Activity Fig. 4.26, p. 88


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