Ecology

• Ecology is the scientific study of the interactions between organisms and their environment.
• Biological Levels of Organizations

  1. Biosphere
  2. Ecosystem
  3. Community
  4. Population
  5. Organism
  6. Organ/Organ System
  7. Tissue
  8. Cell
  9. Organelle
  10. Molecule
• Abiotic Factors in the Biosphere

  • Energy
  • Temperature
  • Water
  • Nutrients
  • Other
• Earth receives uneven distribution of solar energy due to earth's uneven axis

  • Equator directly receives the sunlight as it's perpendicular to the sun
  • Arctic and Antarctic receives the least sunlight because it's at a slant
• Phases of Sunlight

  A) 23.5

  B) Northern

  C) toward

  D) March

  E) December

  F) away from

  G) September

  
• Aquatic Ecosystems

  • Oceans (salt water)
  • Estuaries (Salt and Fresh Water)
  • Wetlands (Salt or Fresh Water)
  • Rivers, Streams, Lakes (Fresh Water)
• Aquatic Ecosystem: Oceans

  A) Intertidal Zone

  B) Continental Shelf

  C) Benthic Realm

  D) Pelagic Realm

  E) Photic Zone

  F) Aphotic Zone

  
• Estuaries

  • Where nutrient-rich streams meet saltwater ocean
  • Birds go to breed
• Coastal Wetlands

  • Either fresh or salt water
  • Farther from salt water ocean
• Wetland

  • Partially/permanently under water
  • Productive
  • Lots of organisms live there
• Stream

  • Nutrient-rich
• Temperate Lakes

  A) Colder

  B) Cold

  C) Mix

  D) Warm

  E) Cold

  F) Mix

  
• Lakes - Importance of Distance from Shoreline

  • How much of the lake is in the photic/aphotic?
  • Nutrients enter in the lake
• What is a eutrophic lake? How does it form?

  • Nutrients are added into the lake (excessive amount)
  • Algae over produce and will be bad for organisms
  • Photic zone doesn't work due to reduced sunlight
  • Die and go to decomposers that take up all oxygen and will become oxygen depleted
• Population Ecology is the study of changes in population size and the factors that regulate population over time

  • What causes the population size to change
• Measuring population density is the population size in a certain area/volume

  • # individuals / m^2
• 3 Distribution Patterns

  • Clumped Dispersion Pattern
  • Uniform Dispersion Pattern
  • Random Dispersion Pattern
• Age Structure of Population

  • Relative # of individuals at different stages of life
  • Can produce a survivorship curve for population
  • Depends on life history traits
• Survivorship Curves

  • Type I: k-species
  • Type III: r-species

  A) Type I

  B) Type II

  C) Type III

  
• Life History Strategies: r-selected species

  • Short-life span
  • Early reproductive age
  • Many offspring
  • Little parental care
• Life History Strategies: k-selected species

  • Long lifespan
  • Late reproductive age
  • Few offspring
  • Extensive parental care
• Population Growth Curves

  1. Exponential Growth
  2. Logistic Growth
• Exponential Growth

  • G = rN
  • J-shaped curve
  • more present = more offspring
• Logistic Growth:

  • G = rN [(K-N)/K]
  • S-Shaped Curve
  • Restricting Population Growth from environmental factors
• Density-Dependent Factors

  • Competition (for limited resources)
  • Habitat Availability
  • Food Availability
  • Mate Availability
  • Disease
  • # of Predators
  • Large population = more predators
• Density Independent Factors

  • Weather
  • Temp
  • Moisture
  • Environment
  • Fire
  • Floods
  • Storms
  • Human Activity
  • Humans cause floods and start fires
• Ecological Footprint

  • Amount of land required to support each individual's needs
  • What impact are we having on the environment
• A community is all of the populations of species in an area that have the potential to interact

  Community Ecology are the interactions within the community
• Species Diversity is measured in 2 ways

  1. Species Richness: # of species present interacting with one another
  2. Relative Abundance: # of individuals of each species
• Interspecific interactions at the community level:

  • Competition
  • Mutualism
  • Predation
  • Herbivory
  • Parasites/Pathogens
• Competition (-/-)

  • Ecological Niche: the sum of biotic/abiotic resources in the environment that an organism uses
  • Overlapping Niches: Interspecific competition, competitive exclusion or resource partitioning
• Mutualism (+/+)

  • Both parties are benefiting from the exchange
  • Example: bees drink nectar from flowers while the flowers are pollenated by the bees.
• Mycorrhizae is another example of mutualism

  • Interaction between fungus and a root of a plant
  • Fungi takes over the root of a plant benefitting the fungi
  • The plants have benefits from increased water and nutrient absorption
• Predation (+/-)

  • One species benefits from the interaction
  • Snake and Deer: Deer is hunted and dies while the Snake hunts and benefits from the interaction
• Herbivory (+/-)

  • Interaction of animals eating plant material

  Herbivores

  • Organism that feeds on plants
  • They have broad and flat teeth with rough surfaces to grind up tough plant tissues
• Coevolution is a change in a species acts as a force on another species, resulting in adaptations of the second species that will affect the selection of the first.
• Coevolution between a caterpillar (heliconius) and a flower (passiflora). flower will produce toxic chemicals that protects its leaves from most insects. the caterpillar were able to adapt to the toxins of the flower which benefits the caterpillar.

  • To fight this, the flower produced eggs that look like the eggs of the caterpillar so they would not be eaten
• Parasitism (+/-)

  • A parasite taking advantage of its host
  • Lice is a prime example
• Autotrophs (Producers) are organisms that can make their own food and source organisms with organic molecules

  • Two types: photoautotrophs and chemoautotrophs
• Decomposition is the breakdown of organic materials into inorganic ones

  • This links all trophic levels