Chapter 2 - ECOLOGY INTRODUCTION NOTES

  1. Ecology – from the Greek work “oikos” which means house. It is the study of interrelationships between organism and their environment.
  2. Ecosystem – self sustaining unit of organisms and their environments.

1.Divisions

1.Biosphere – earth including water, air, land and living organisms. Extends 8 km above and below the surface.

2.Biome – subdivision of biosphere.

  1. Land – characterized by dominant vegetation and type of climate
  2. Aquatic – characterized by type of water and location

3.Community – group of interacting species that co-exist in an ecosystem. Forms a system of producer, consumers and decomposers.

4.Population – division of a community made of individual species which share a common area.

2.Environmental factors

1.Abiotic factors – non-living factors i.e. temperature, sunlight, soil type, water, minerals, pollution

2.Biotic factors – living factors i.e. plants, animals, bacteria, fungi, etc.

  1. Forces of a Community
  2. Competition – competition for a limited resource can inhibit the growth of both population or even eliminate one of the populations. Pg. 38
  3. Predation – one species eats the other – includes both plants and animals – Pg. 38

1.Coevolution – a series of reciprocal adaptations in two species which effect the survival of both – ex. Butterfly and leaves - pg. 439

2.Camouflage – common defense of prey – pg. 428

3.Batesian Mimicry – one species mimics another undesirable species – pg. 429

4.Mullerian mimicry – two unpalatable species in the same community mimic each other – pg. 429

  1. Symbiotic Relationships – pg. 39 - 40

1.Parasitism – one organism derives food at the expense of another organism

2.Commensalism – one partner benefits without significantly harming the other

3.Mutualism – both partners benefit

  1. Energy Flow –
  2. Food Chains and Webs - Sun ------producer ------consumer

Producer = autotroph – always base level in chain , web or pyramid

1.Consumer = heterotroph – makes us the levels after the first one

2.Decomposer = Breaks down dead organisms. Detritivores eat fragments of dead matter

3.Food Chain – path of energy flow from producer to consumer. Only 10% of energy is transferred to next level. Each feeding level is called a trophic level. Arrows point in the direction of the energy flow – not who eats what.

4.Food Web – interconnected food chains

  1. Pyramids

1. Pyramid of Energy –pg. 44 – Each level represents the amt. of energy available to trophic level. Remember – 90% of energy is lost between each level

2.Pyramid of Biomass – pg. 44 – Each level represents the amt. of biomass consumed – Usually the available amt. of biomass decreases with each level

3.Pyramid of Numbers – pg. 44 – Each level represents the number of individual organisms consumed – Usually the population size decreases with each level

  1. Biogeochemical Cycles – Exchange of matter through the biosphere which includes the living organisms, chemical processes and geological processes
  2. Hydrologic Cycle – needed for life

1. Water evaporates from soil, organisms and bodies of water into atmosphere

2.Water vapor rises and cools in the atmosphere forming clouds.

3.Water returns to earth thru rain, sleet and snow

  1. Carbon Cycle – necessary to make organic compounds

1.Carbon dioxide and water are used during photosynthesis to produce glucose

2.Glucose is broken down during cellular respiration to produce carbon dioxide, water and ATP

3.Carbon dioxide buried in fossil fuels is released when those fuels are burned

4.Carbon is also stored in calcium carbonate shells and released when the shells decompose.

  1. Nitrogen Cycle – Nitrogen needed to make proteins

1. Largest concentration is in atmosphere but plants and animals cannot use the nitrogen gas.

2.Bacteria in the soil, water and on the roots of plants absorb the nitrogen gas and modify it to a form usable by plants and animals. (Nitrogen fixation)

3.Nitrogen is transferred between trophic levels and is recycled into needed amino acids.

4.Nitrogen released from organisms during urination, decomposition and conversion of ammonia.

  1. Phosphorous Cycle – is necessary for nucleic acids

1.Stored in rocks and absorbed by producers for transfer to upper trophic levels

2.Returns to soil during decomposition and the weathering and erosion of rocks

BIOME ASSIGNMENT – on the paper provided write the name of your biome.

Now ILLUSTRATE:

  1. Climate and abiotic factors
  2. Characteristic plants and animals
  3. 3 level food web with at least two organisms at each level.