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Ecology Chapter Notes
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Levels
• Our book lists 5 levels
-> organism->population->community->ecosystem->biosphere
• What about -> cell-> organ-> system are they levels of biological organization?
• and.... What is living!!!
These are all living factors, levels of Biological Organization.... but cells are made of molecules, molecules are made of atoms.
Does that make molecules and atoms living since they make up living organisms??? Thus -> atoms -> molecules?
Some Biotic Factors to consider when studying Environment
Population Density
• Population density is the biological measurement most used by conservationists vs population size.
• Population density = Population of an organism / Area population lives in. In Km2
• indicates areas of high growth or potential stress on ecosystems
What are the 3 countries with the greatest overall Population?
What are the 3 countries with the greatest Population Density?
Population Density Problem (Solve in your NOTES!)
1. Calculate the Population Density for these 3 countries and rank each from highest population density to lowest. Use a calculator
Rank Country/Region Population Area (km2) Density(Pop/km2) .
Japan .
.
Mexico .
.
South Korea .
Show World Population video
Biotic potential: The maximum reproductive capacity of a population under optimum environmental conditions is the biotic potential.
• Often restricted by conditions that inhibit the increase in number of the population. (Food availability, disease, lack of mates)• Generally only reached when environmental conditions are very favorable.
• A species reaching its biotic potential would exhibit exponential population growth (many offspring are produced per mother
• Biotic Potential is a basic characteristic of a species.
Carrying CapacityIn ecological terms, carrying capacity of an ecosystem is:
• The size of the population that can be supported indefinitely with the available resources and services of that ecosystem.Living within the limits of an ecosystem depends on three factors
1. the amount of resources available in the ecosystem,2. the size of the population, and
3. the amount of resources each individual is consuming.
(ex: food, habitat, water etc)
• In the natural world, when a population's density is less than the carrying capacity of the ecosystem that population can increase…• As animal population density increases beyond the carrying capicity, birth rates often decrease and death rates typically increase.
o resources decline and become Limiting Factors
Limiting Factors (restricting factors)
•things that limit individuals in a specific population•can be abiotic (lack of water - heat etc)
•or biotic ( predators, disease, competition for food sheep and cows)
Interrelationships between species
Symbiosis ( the study of the relationship between two or more species) three types
1. Mutualism a relationship where both (all) species benefit
ex lichen - algae and fungi Algae get a place to live give Fungi food in form of sugar.
2. Commensalism - benefits one species, not the other species
ex: orchids on tree orchid gets place to live, tree gets nothing, but doesn't lose anything either.
3. Parasitism - one species harms the other ex tapeworm harms human, mistletoe, trichina
What is the Deer's habitat?
What is the Deer's niche?
Habitat - creature's home... where a creature lives in the environment
ex: wetland creature, arctic tundra plant, swamp plant etc.Niche - what a creature does to make a living in the environment...
ex: what it eats is what it does to "Make a living".Another way of looking at it is a niche is how an organism gets energy to survive, ie herbivore get energy from plants to survive.
Abiotic Factors - non living factors in the environment -
• It's not as simple as the book says - they list four major (water, soil, light, temp)• In reality, there are other abiotic factors - energy, air, fire, spacing, essential elements, etc
Cycles
Discuss cycles = Diagrams that follow specific nutrients through the environment
ex. Water cycle, Nitrogen cycles, Carbon cycle, Rock cycle.....
Nutrient Cycles: Cycle vital elements and minerals that organisms need to live through the environment. Some examples of nutrients are:
Water: (Water Cycle) Required for all living thingsCarbon: (Carbon Cycle) Required for all living organisms.
Oxygen: Photosynthesis (Oxygen Cycle) CO2 + H2O + Sun => Sugar + Oxygen
Nitrogen: (Nitrogen Cycle) both plants and animals need Nitrogen to build new nitrogenous bases which are the foundation of DNA.
Rock cycle - Forms basis of soil. Contains vital trace minerals (Micronutrients)
- Ex: plants need Magnesium to make chlorophyll so they can photosynthesize.
Others are Sulfer, Phosphorous, Selinium, Iron, Potassium, etc
