3POS Checklist:investigate and analyze an aquatic or a terrestrial local ecosystem, distinguish between biotic and abiotic factors, describe how these factors affect population size andinfer the abiotic effects on life.infer biotic interactions.infer the influence of biota on the local environment.
4It is the narrow zone around the earth where life exists. AtmosphereThe biosphere is made up of three parts:HydrosphereLithosphere
5There are two factors that affect any part of the biosphere: Biotic Factors: living organisms (life forms).Abiotic Factors: nonliving components (geological and physical factors).Question: what are some biotic and abiotic factors in a lake?
6When we study living systems, we will be looking at the following: Organism (the individual).Population (group of individuals).Community (one or more populations).Ecosystem (community and abiotic factors that interact).*Using the Prairies, give examples of each of the 4 parts of a living system.
7Habitat Habitat: abiotic and biotic factors that encourage survival. Water is the most important abiotic factor of an ecosystem.The habitat of an organism determines the amount of water, sunlight and temperature for growth and survival.*What is your ideal habitat? Why?
8Nutrients One component of habitat is chemical nutrients. Nutrients are needed compounds/elements used by organisms to grow and reproduce.Gardeners use fertilizers to give all the needed nutrients to the plants.The run-off from fertilizers can cause problems with lakes and algal blooms.
9Fertilizers- chemicals that contain nitrogen and phosphorus natural fertilizer.Manure: contains N which is ammonified first in the soil, then nitrified to provide useful nitrates.Commercial Fertilizers: 3 numbers:The first number is the % nitrogen (by weight)The second number is the % phosphorus (by weight)The third number is the % potassium (by weight)
10This fertilizer contains 34% ___________ and 64% filler.
11This diagram shows some of the major, minor and micro nutrients a plant needs. Note that K, N and P are all major nutrients.
12Adding fertilizers to crops has been good for society: What are some advantages of using fertilizers?-However, there have alsobeen negative side effects.
13While fertilizers help our crops grow, they also increase the growth of some unwanted plant life. Often, fertilizers run off into lakes, creating high concentrations of chemicals.The natural algae in these lakes start to grow uncontrollably: resulting in a lake full of algae.
14This process is called eutrophication: - a process in which nutrient runoff from agricultural lands or livestock operations causes photosynthetic organisms in ponds and lakes to multiply rapidlyHuman-caused eutrophication wiped out fisheries in Lake Erie in the 1950s and 1960s.
15LAKE EUTROPHICATIONAlgae die food for decomposers population growsHigh levels of P and N containing compounds (fertilizers/ detergents)Algal Bloom(rapid growth of algae)Low oxygen other organisms die outDecomposers (bacteria) break down material and use up oxygen in lakeOrganisms living in this part of the lake also feed on decaying plant and animal remains that wash into the water from the landFreshwater biomes located near areas with human populations often contain high concentrations of phosphorus and nitrogen compoundsThese compounds come from fertilizers and detergents used by peoplePhosphorus and nitrogen compounds that enter lakes, ponds, and streams serve as nutrients for algae and plantsBut if too many nutrients are present, algae and plants may grow out of controlThese large populations eventually begin to die and decayAs decomposing bacteria break down the remains, they use up much of the oxygen dissolved in the waterThe resulting oxygen-poor water becomes uninhabitable for protozoa, fish, and other small animalsWater in which oxygen becomes too low to support animal life is called eutrophic water.15
16To protect Canadian lakes, ponds, and streams from becoming eutrophic, some states no longer allow the sale of detergents containing phosphorus compounds.
17A surplus or lack of oxygen does occur in lakes naturally as well. Oligotrophic lake: Nutrient-poor, photosynthesis-limited, clear water, O2 rich.Eutrophic lake: Nutrient-rich, high photosynthesis, murky water, O2 poor.
19Hydrological (water) Cycle Water plays a critical role by:Maintaining global heat balance.Acting as a solvent in reactions.Movement of water through environment: from atmosphere to Earth.Volume of water remains constant, specific amounts vary in phases; water continuously cycles.
23Biotic FactorsWe have looked at some abiotic factors so far, now we will look at some biotic factors that affect ecosystems:Symbiosis = “living together”Long lasting relationship that benefits at least one organism of two different species.
24Types of symbiosis: Mutualism: both species benefit. Read the paragraph on page 416 to determine the mutualism between prairie dogs and bison.
25- Commensalism: one organism benefits, the other is unaffected/unharmed. Read the paragraph on page 417 to determine the mutualism between cowbirds and bison.
26- Parasitism: one organism (parasite) benefits by harming the other (host). Read the paragraph on page 417 to determine the mutualism between cowbirds and the yellow-rumped warbler.
27Predator-Prey Interactions This is NOT symbiosis; the two organisms do not live together and it is a short interaction.Predation: one organism (predator) kills the other (prey).Mostly benefits the predator BUT the prey community is left with fit individuals.
31Assignment Please complete the following: Read and highlight the important points on “biomes and habitats” and “animal partnerships”.Complete #2,3 and 4 on page 412.Complete the Symbiosis Fact sheet.Complete #2,3,5 on page 422.