Ecology

1
Ecology
2
What is Ecology?

• Ecology is the study of interactions among
  organisms and between organisms and their
  environment.
• There are many levels of organization ecologists
  study

3
Levels of Organization
4
Levels of Organization

• Species can breed and produce fertile offspring
• Population same species in same area
• Community different populations in same area
• Ecosystem all organisms (biotic) in particular
  place includes nonliving (abiotic) surroundings
• Biome group of ecosystems with same climate
  (temperature and precipitation) and similar
  communities
• Biosphere all portions of the planet where life
  exists (land, water, air, atmosphere)

5
Basic Terminology

• Ecosystem All the biotic and abiotic factors in
  an environment
• Heat Energy Form of lost energy, 90 of
  available energy is lost in the form of heat.
• Chemical Energy Glucose transfer in the food
  chain
• Light Energy Originating source of Energy from
  the sun (Main source of energy)

6
Energy Flow Summary

• Energy flows in one direction through an
  ecosystem, from the sun or inorganic compounds to
  producers (organisms that can make their own
  food) through various levels to consumers
  (organisms that rely on other organisms for
  food).

7
Energy Flow

• Producers Autotrophs
• Photosynthesis Vs. Chemosynthesis
• Consumers Heterotrophs
• Herbivores
• Carnivores
• Omnivores
• Detritivores
• Decomposers
• Scavenger

8
Trophic Levels
9
Feeding Relationships

• Food chain series of steps (linear)
• Food web links all food chains together
• Trophic level each step in a chain or web

10
Ecological Pyramids
11
Energy Pyramid Shows the relative amount of
energy available at each trophic level.
Organisms use about 90 percent of this energy
for life processes. Only 10 is transferred.
12
Biomass PyramidRepresents the amount of living
organic matter at each trophic level.
Typically, thegreatest biomass is at the base
of the pyramid.
13
Pyramid of Numbers Shows the relative number
of individual organisms at each trophic level.
14
Cycling of Nutrient and Matter

• Remember Energy flows in one direction and
  matter cycles.

15
Recycling in the Biosphere

• Unlike the one-way flow of energy, matter is
  recycled.
• Matter moves through an ecosystem in
  biogeochemical cycles.
• Matter is recycled because systems do not use up
  matter, they transform it.

16
Four Main Cycles

• Water Cycle
• Nutrient Cycles
• Carbon Cycle
• Nitrogen Cycle
• Phosphorus Cycle

17
Water Cycle

• 1. When rain falls on the ground, it either soaks
  into the soil or runs across the surface of the
  soil. When rainwater runs across the land, what
  body of water might collect the rain?
• 2. From here, where might the water flow?
• 3. After the rain, the sun comes out and the land
  dries. Where does the water that had been on the
  land go?

18
Water Cycle

• Water moves between the ocean, atmosphere, and
  land.
• Steps of the water cycle
• Evaporation Transpiration
• Condensation
• Precipitation
• Runoff
• Seepage
• Groundwater

19
Water Cycle

• Sketch a simple diagram of the water cycle in
  your notes.

20
Nutrient Cycles

• Every organism needs nutrients to grow and
  function. Like water, nutrients are also
  transferred in cycles.
• 3 Nutrient Cycles
• Carbon
• Nitrogen
• Phosphorus-mostly in rocks and soil minerals

21
Carbon Cycle
CO2 in Atmosphere
CO2 in Ocean
22
Carbon Cycle

• Four main types of processes move carbon through
  its cycle
• Biological processes, such as photosynthesis,
  respiration, and decomposition, take up and
  release carbon and oxygen.
• Geochemical processes, such as erosion and
  volcanic activity, release carbon dioxide to the
  atmosphere and oceans.

23
Carbon Cycle

• Mixed biogeochemical processes, such as the
  burial and decomposition of dead organisms and
  their conversion under pressure into coal and
  petroleum (fossil fuels), store carbon
  underground.
• Human activities, such as mining, cutting and
  burning forests, and burning fossil fuels,
  release carbon dioxide into the atmosphere.

24
Nitrogen Cycle
N2 in Atmosphere
NO3- and NO2-
NH3
25
Nitrogen Cycle

• Bacteria that live in the soil and on the roots
  of legume plants convert nitrogen gas to ammonia
  through nitrogen fixation.
• When organisms die, their ammonia can be
  converted back to nitrogen gas through
  denitrification.

26
Phosphorus Cycle

• Phosphorus is essential to living organisms
  because it forms part of important
  life-sustaining molecules such as DNA and RNA.
• Phosphorus remains mostly on land in rock and
  soil minerals, and in ocean sediments.
• It is not very common in the biosphere
• phosphorus exists in the form of inorganic
  phosphate.
• As the rocks and sediments gradually wear down,
  phosphate is released.
• On land, some of the phosphate washes into rivers
  and streams, where it dissolves.
• The phosphate eventually makes its way to the
  oceans, where it is used by marine organisms.

27
Phosphorus Cycle