Ch.%203-%20The%20Biosphere

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Ch. 3- The Biosphere
ECOLOGY!
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3.1 Levels of Organization
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What is Ecology?

• Study of interactions
• among organisms and
• between organisms and their environment

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Biosphere

• All portions of planet in which life exists
• Land
• Air
• Water

atmosphere
land
water
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Interactions

• Interactions w/in biosphere
• Web of interdependence between organisms and the
  environment
• Ever changing biosphere

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Levels of Organization
Individual living thing of a single species
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Levels of Organization
Population group of organisms of same species
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Levels of Organization
Community Populations that live together
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Levels of Organization
Ecosystem community nonliving surroundings
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Levels of Organization
Biome group of ecosystems with same climate
and similar dominant communities
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Levels of Organization
Biosphere contains ALL ecosystems biomes
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Ecosystem Processes
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Thinking Question

• While browsing through the drinks offered at a
  convenience store, you notice a new soft drink
  advertised as a low-calorie energy drink. Write
  out your definition of energy, and then decide
  if this drink label is accurate or a case of
  false advertising.

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Energy

• Energy is defined as the ability to do work.
• Energy is NOT a material. Energy is a phenomenon.
• Energy can be transformed (i.e. mechanical to
  heat) and transferred, but is not recycled.

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Energy flows

• Energy for most ecosystems on earth comes from
  the sun.
• Light energy is converted to chemical energy by
  producers to power their own metabolism.
• Energy is lost from the earth as heat.

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Photosynthesis

• Energy is converted and nutrients are fixed by
  the process of photosynthesis.
• Producers use the suns energy to convert
  inorganic carbon dioxide into organic molecules,
  such as sugars.

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Biomass (g/m2)
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Thinking question discussion

• So what about that low-calorie energy drink?

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Energy Flows
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Thinking Question

• One reason that some people become vegetarians is
  to reduce their impact on the environment. List
  as many positive ecological effects of
  vegetarianism as you can think of. Then list as
  many negative effects.

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Food Chain Concept

• Chemical energy is passed through the ecosystem
  as organisms consume other organisms.
• Organisms occupy one or more trophic levels
  (feeding levels) depending on what they are
  eating.

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Trophic Levels

• Producers Use light energy to manufacture
  organic molecules.
• Primary consumers eat producers
• Secondary consumers eat primary consumers
• Tertiary consumers eat secondary consumers.

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Food Webs

• A food web is a model of energy flow in a
  community.
• Arrows indicate the direction in which energy
  flows from one organism to the next. (Note that
  this is NOT a cycle.)
• A single organism will be involved in many food
  chains, and some will occupy several trophic
  levels.

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Death Eaters

• Decomposers Bacteria and fungi, which use
  external digestion to break organic matter down
  into inorganic substances.
• Detritivores Animals that feed on dead plant
  material.
• Scavengers Animals that feed on dead animal
  flesh.

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Energy Loss

• At each step in a food chain or food web, energy
  is lost as heat. Each organism takes in energy to
  meet its own needs, so most of the energy taken
  in is converted to motion and heat.
• 10 or less of the energy consumed will be
  available to the next consumer.

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Energy Pyramid

• Because 90 or more of consumed energy is used by
  the organism, and only a small amount can be
  passed on, the entire system is inefficient.
• The higher an organism is on the food chain, the
  greater amount of biomass is required to support
  that organism.

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Its all about ENERGY!

• Arrows show direction of ENERGY flow
• NOT direction of eating

Grass
Cow
Grass
Cow
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Energy

• Energy is defined as the ability to do work.
• Energy is NOT a material. Energy is a phenomenon.
• Energy can be transformed (i.e. mechanical to
  heat) and transferred, but is not recycled.

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Thinking Question

• One reason that some people become vegetarians is
  to reduce their impact on the environment. List
  as many positive ecological effects of
  vegetarianism as you can think of. Then list as
  many negative effects.

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Energy Pyramid

• Relative energy amounts at each trophic level
• Only 10 energy passed on from one level to the
  next

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Biomass pyramid
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Thinking question discussion

• What are possible positive and negative effects
  of going veggie?
• How can your everyday food choices have an impact
  on the environment?

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Bioaccumulation/Biomagnification

• Buildup of chemicals inside organisms.
• Organisms cant break down (metabolize) the
  chemicals OR
• Chemicals are taken up faster than they are
  broken down

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Big Problem

• Mercury, pesticides (DDT) buildup in fish
• Once a pollutant is in the soil, it can easily
  enter the waterways and thus, food chains

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• At lower trophic levels (producer), the
  contaminant may not cause much harm, but as you
  move higher into the food chain, the levels
  increase. This phenomenon is referred to as
  BIOMAGNIFICATION!

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Human Food Chain

• Humans are omnivores, capable of eating a wide
  variety of foods.
• We can create a human food chain by looking at
  our meat sources.

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Grass-fed Food Chain
A cow can convert grass, which we cannot eat,
into meat, which we can.
We obtain 8-10 of the energy that a pasture-fed
cow consumes.
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Industrial Food Chain
Corn, which could be fed to humans, is fed to
feedlot cattle. Because of overproduction, corn
is cheap.
Cheap burgers come at a high ecological cost. The
industrial food chain is about 1/3 as efficient
as the grass food chain.
A cows digestive system is not adapted to eating
corn. The cattle are often sick, and much of the
energy is wasted.
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Nutrients Cycle
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Thinking Question

• Global climate change has everyones attention
  these days. One action that some people take in
  response is to plant trees. What does planting
  trees have to do with alleviating global climate
  change?

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Nutrients

• Nutrient in an ecological sense refers to the
  inorganic materials taken in by producers and
  converted into organic molecules.
• Nutrients include carbon (as carbon dioxide),
  nitrogen, phosphorous, oxygen, and other building
  blocks of biological molecules.

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Nutrients Cycle

• Because nutrients ARE materials, they cycle in
  the earths ecosystems. Carbon from carbon
  dioxide may become carbon in a sugar made by a
  plant.
• Decomposers break down organic molecules and
  release inorganic nutrients to the ecosystem.

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Material Cycles

• Material cycling follows the law of conservation
  of matter.
• Elements used by living organisms are taken up
  and used by producers, used passed down the food
  chain by consumers, and are released back to the
  environment by decomposers.

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Carbon Cycle

• Carbon forms the backbone of all organic
  molecules.
• Carbon from the atmosphere is fixed by
  producers, which manufacture organic molecules
  using the suns energy.
• Breakdown of these molecules releases carbon
  dioxide back to the atmosphere.

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Carbon Cycles

• Biological
• Photosynthesis, respiration, and decomposition
  (take up and release CO2)
• Geochemical
• Erosion, volcanic activity (release CO2)

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Carbon Cycle
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2 Biggest Biological Carbon Movers

• Photosynthesis and respiration

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The Carbon Cycle
CO2 in Atmosphere
CO2 in Ocean
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Nitrogen Cycle

• The earths atmosphere is 78 nitrogen, but in
  this form it cannot be used by producers.
• Nitrogen-fixing bacteria convert nitrogen gas
  into nitrogen compounds that plants can absorb
  and use in making amino acids to build proteins.

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The Nitrogen Cycle

• Nitrogen is required for amino acids
• Most of the atmosphere is made of nitrogen (78)
• Most decaying matter (detritus) produces ammonia
  (NH3), Nitrate ions (NO3-), and others
• Bacteria convert nitrogen into plants (nitrogen
  fixation)
• Some bacteria convert nitrates into N gas which
  is called denitrification

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Nitrogen Cycle
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The Nitrogen Cycle
N2 in Atmosphere
NO3- and NO2-
NH3
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Phosphorous Cycle

• Unlike other nutrients, phosphorous does not
  exist as an atmospheric gas.
• Rock phosphates dissolve in rain as rock
  weathers, carrying phosphates into streams and
  soil.
• Phosphates settle out on the bottoms of ponds,
  and may consolidate back into phosphate-rich rock.

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Phosphorus Cycle

• Used to make DNA and RNA (Ph backbone)
• Not very common in the biosphere
• Does not enter the atmosphere
• Usually in rock and soil minerals
• Dissolves in water

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Phosphorous Cycle
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Water Cycle

• Weather patterns form part of the water cycle.
• Water remains chemically unchanged during the
  water cycle. It is evaporated as water vapor,
  condensed into rain clouds, and finally falls as
  precipitation.
• Water may collect in rocks as groundwater.

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Water Cycles

• All living things require water
• Water is recycled in the biosphere in the water
  cycle through
• Evaporation - water to gas (vapor)
• Transpiration evaporation from plants
• Condensation vapor ?water droplets that form
  clouds
• Precipitation rain, snow, hail, and sleet

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Water Cycle
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The Carbon Cycle

• Carbon is the key element in living tissue
• Carbon dioxide, Glucose, Calcium carbon (bones)
  and more include carbon!
• Carbon is moved throughout the environment in the
  carbon cycle

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Global Warming

• Global Warming better termed Global Climate
  Change has been strongly linked to levels of
  carbon dioxide in the atmosphere.
• The warming of the Earths temperature (surfac
  eand air)
• While natural events add carbon dioxide to the
  atmosphere, humans activity also contributes to
  carbon levels.

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Fossil Fuels

• Fossil fuels are the remains of ancient swamps.
  Plants fixed carbon as carbon-rich organic
  compounds. Carbon compounds accumulated in swamps
  over hundreds of millions of years.
• In less than 200 years, humans have burned nearly
  half of the worlds fossil fuels.

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Greenhouse Gases

• Earths atmosphere has many different gases, inc.
  water vapor and CO2.
• These GREENHOUSE GASES help maintain Earths
  constant temperature
• No greenhouse gases very COLD atomosphere)
• Too many greenhouse gases EXCESSIVE HEAT

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Greenhouse Effect
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Impacts of Human Domination of Cycles

• Increased global concentrations of greenhouse
  gases like nitrous oxide (N2O), carbon dioxide
  (CO2), which are potent greenhouse gases, in the
  atmosphere as well as increased regional
  concentrations of other oxides of nitrogen
  (including nitric oxide, NO) that drive the
  formation of smog
• Losses of soil nutrients such as calcium and
  potassium that are essential for long-term soil
  fertility
• Substantial acidification of soils and of the
  waters of streams and lakes in several regions
• Greatly increased transport of nitrogen by rivers
  into estuaries and coastal waters where it is a
  major pollutant.
• We are also confident that human alterations of
  the cycles have
• Accelerated losses of biological diversity,
  especially among plants adapted to low-nitrogen
  soils, and subsequently, the animals and microbes
  that depend on these plants
• Caused changes in the plant and animal life and
  ecological processes of estuarine and nearshore
  ecosystems, and contributed to long-term declines
  in coastal marine fisheries.

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Carbon and Temperature
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Future Trends?
The outcome depends on what happens to the west
Antarctic ice shelf.
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Current Effects
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Photosynthesis

• Energy is converted and nutrients are fixed by
  the process of photosynthesis.
• Producers use the suns energy to convert
  inorganic carbon dioxide into organic molecules,
  such as sugars.

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Food Chain Concept

• Chemical energy is passed through the ecosystem
  as organisms consume other organisms.
• Organisms occupy one or more trophic levels
  (feeding levels) depending on what they are
  eating.

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Trophic Levels

• Producers Use light energy to manufacture
  organic molecules.
• Primary consumers eat producers
• Secondary consumers eat primary consumers
• Tertiary consumers eat secondary consumers.

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Producers

• Autotrophs
• Energy from the sun (photosynthesis)
• Energy from chemical bonds (chemosynthesis)

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Consumers

• Heterotrophs
• Herbivores only eat plants
• Carnivores only eat animals
• Omnivores eat both plants animals

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Decomposers

• Detritus plant animal remains/ dead matter
• Earthworms, snails
• Decomposers break down organic matter
• Bacteria, fungus

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Death Eaters

• Decomposers break down organic matter down into
  inorganic substances.
• Ex. Bacteria, fungi
• Detritivores Animals that feed on dead plant and
  animal remains/dead matter
• Earthworms, snails
• Scavengers Animals that feed on dead animal
  flesh.

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Feeding Relationships

• Energy flows through ecosystem in one direction

Sun / Inorganic compounds
Producers
Consumers
Arrow direction of energy flow
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Food Webs

• A food web is a model of energy flow in a
  community.
• Arrows indicate the direction in which energy
  flows from one organism to the next. (Note that
  this is NOT a cycle.)
• A single organism will be involved in many food
  chains, and some will occupy several trophic
  levels.

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Trophic Levels Each level in food chain
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3.3Cycles of Matter
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Nutrients

• Nutrient in an ecological sense refers to the
  inorganic materials taken in by producers and
  converted into organic molecules.
• Nutrients include carbon (as carbon dioxide),
  nitrogen, phosphorous, oxygen, and other building
  blocks of biological molecules.

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Nutrients Cycle

• Because nutrients ARE materials, they cycle in
  the earths ecosystems. Carbon from carbon
  dioxide may become carbon in a sugar made by a
  plant.
• Decomposers break down organic molecules and
  release inorganic nutrients to the ecosystem.

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Nutrient Cycles

• Nutrients chemical substances in organisms that
  are necessary to sustain life
• Building blocks
• Nutrients are passed between organisms and
  environment in the biogeochemical cycles

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Material Cycles

• Material cycling follows the law of conservation
  of matter.
• Elements used by living organisms are taken up
  and used by producers, used passed down the food
  chain by consumers, and are released back to the
  environment by decomposers.

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Recycling

• As you know Energy flows in ecosystems in one
  way (sun?prod.?Cons.)
• However elements, compounds, and other forms of
  matter are passed from one part of an ecosystem
  to another in a cycle
• Examples are
• The water cycle
• The nutrient cycles
• Carbon, nitrogen, and phosphorus

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Nitrogen Cycle

• The earths atmosphere is 78 nitrogen, but in
  this form it cannot be used by producers.
• Nitrogen-fixing bacteria convert nitrogen gas
  into nitrogen compounds that plants can absorb
  and use in making amino acids to build proteins.