Presentation on theme: "Environmental Science"— Presentation transcript:
1Environmental Science Unit 2 – Ecological Interactions
24.1 Roles of Living Things Objectives Identify the roles of producers, consumers and decomposersDescribe the concept of tropic level.
3Chapter 4 Role of Living Things Producers: Photosynthesizing organismsConsumers: any organism that can’t make its own foodHerbivore – eats only plantsCarnivore – eats only herbivores or other carnivoresOmnivores - eats either producers or consumersScavengers – feed on bodies of dead organismsLevels of consumers : Primary – eats plantsSecondary – eats animals that eat plantsTertiary – eat animals that eat animals that eat plantsDecomposers: An organism that primarily feeds on dead organisms or the waste from living organisms mainly bacteria and fungi
4Trophic LevelsA layer in the structure of the feeding level of a systemsHeterotrophs: eatother organismsAutotrophs: maketheir own food
54.2 Ecosystem Structure Objectives Describe food chains and food webs. Examine the effects of ecosystem structure on population size and pollution.
6Chapter 4 Ecosystem Structure Food Chain: a series of organisms that transfer food between the tropic levels of an ecosystemsFood Web: a network of food chains = not simple !
7Chapter 4 Interconnections Example:Whales were over huntedTheir primary food source (krill) became over abundant.More krill meant more penguins & seals
8Chapter 4 Diversity and Stability Which food web represents a more mature ecosystem?Which food web is more stable?
9Chapter 4 Biological magnification There are increasing concentrations of pollutants in organisms at higher trophic levels of food websMore
104.3 Energy in the Ecosystem ObjectivesInvestigate the movement of energy through an ecosystem.Define ecological pyramid, and explain its relationship to energy in an ecosystem.
11Energy and FoodProducers use little of the sunlight that reaches them, the energy captured is used to make cells in both producers and consumers. The total amount of organic matter present in a trophic level is called biomass.10% Law
1210% Law10% Law is the main reason most food chains have five or less links. In this example – the biomass of the owl population simply could not support another level.
13Ecological PyramidEcological Pyramid is a diagram that shows the relative amounts of energy in different trophic levels in an ecosystem.
14Biomass PyramidEcological Pyramids can show the biomass and numbers (of organisms) as well as energy.
154.4 Chemical Cycles Objectives Describe the chemical composition of the human body.Explain the water cycle, the carbon cycle and the nitrogen cycle.
16The Human Body4 elements make up 96% of your body.Oxygen 65%Carbon 18.5%Hydrogen 9.5%Nitrogen 3.5%the rest ~4%
21Chapter 5.1 Habitats & Niches Describe the concept of niche.Examine how interactions between a species and its environment define the species’ niche.Species with narrow niches are called specialists (e.g. anteater).Species with broad niches are called generalists (e.g. common crow).
22Niche refers to a populations role in its ecosystem Chapter 5.1 NichesNiche refers to a populations role in its ecosystemfoodhabitatreproduction methodSpecies with narrow niches are called specialists (e.g. anteater).Species with broad niches are called generalists (e.g. common crow).
24Chapter 5.1 Competitive Exclusion CricketsAntsOverlapping niches – species can coexistHawksOwlsBoth species share the same niche – one will disappearThe extinction of a population due to direct competition with another species for resources is
25Chapter 5.1 Niche Diversity Predator is an organism that actively hunts other organisms.Keystone predator is an animal that causes a large increase in the diversity of its habitat.
26Chapter 5.2 Evolution and Adaptation Explain how a species adapts to its niche.Describe convergent evolution and coevolution, and relate each to the concept of niche.
27Chapter 5.2 EvolutionEvolution, changes in a population of organisms over time.
28Chapter 5.2 Evolving to the Niche Populations evolve by adapting to niches in the environment, dividing available resources (avoiding competition)Specialized speciesvs.Generalized species
29Chapter 5.2 Specialized species vs.Generalized species A species closely fit to a specific environment and able to tolerate little change in that environment.A species that can survive in a variety of ecological niches.Ex: Koala feed on EucalyptusEx: Humans
30Chapter 5.2 Convergent Evolution Convergent Evolution, is development of similar adaptations in two separate species with similar niches
31Chapter 5.2 CoevolutionCoevolution, species which interact closely and adapt to one-and-other (even predator & prey) - evolve together
37Chapter 6.1 Relationships in the Ecosystems ObjectivesExplain the relationship size between populations sizes of predator and preyDefine symbiosis and state the effects of symbiotic relationships on populations
38Chapter 6.1 - Predator and Prey Predator – a consumer that actively hunts and prey – organisms upon which predators feeds
39Chapter 6.1 - Predator and Prey Population Cycles The populations of predator and prey are closely linked.Snowshoe hare =Lynx =N1N2
40Chapter ParasitismParasitism – one organism feeds on the tissues or body fluids of anotherEyelash MiteKeys to Parasite survivalEat enough to live and reproduceBut not so much that you kill your host
41Chapter SymbiosisSymbiosis – a relationship where two species live together closely. Parasitism is an example of symbiosis.CommensalismOne species benefits, and neither helps nor harms the otherMutualismBoth species benefits
42Chapter 6.2 Ecological Succession ObjectivesDescribe the process of primary and secondary successionIllustrate the evolution of many species from a single ancestor during the process of island succession
43Chapter 6.2 Ecosystem Successions Primary SuccessionSequence of communities forming in an originally lifeless habitat
44Chapter 6.2 Lichens Lichens A fungus and an algae living in a mutualistic relationshipImportant because able to break down bare rock using stored acidPioneer community
45Chapter 6.2 Climax Community Community that does not undergo further succession
46Chapter 6.2 Secondary Community Succession that occurs when a community has been cleared by a disturbance, but does not disturb the soil
47Chapter 6.2 – Other Successions Aquatic Such as what might happen in an oxbow lakeIsland succesion, birds often populate unfilled niches.Darwin’s Finches
48Chapter 6.3 Balance in the Ecosystem ObjectivesExamine the concepts of ecosystem balance and explain how humans affect that balance.Explain that disturbance is a natural part of all ecosystems, but that disturbances trigger changes in ecosystems.
49Chapter 6.3 Balance in the Ecosystem All natural ecosystems are stable, they maintain a state of balance called equilibrium.Food-web is heart of the system
50Chapter 6.3 Human affect on Balance Humans build houses such that salamanders vernal pools are eliminated, what might happen?Chapter 6.3 Human affect on BalanceVOID
51Chapter 6.3 Balance Cause/Effect Extinction of dinosaursRapid evolution of mammals
52Define the concept of a biome and name the eight major biomes. Chapter 6.4 Land BiomesObjectivesDefine the concept of a biome and name the eight major biomes.Illustrate where each of the eight major biomes occurs.
53Chapter 6.4 BiomesBiome a major type of ecosystem with distinct temperature, rainfall & organisms
54Forest Biomes account for 75% of earth’s biomass Chapter 6.4 Forest BiomesForest Biomes account for 75% of earth’s biomassReceive abundant precipitationConiferous (sometimes refered to as ‘taiga’)Deciduousfour distinct seasons, spring, summer, autumn, and winter.RainOnly account for 6% of earth’s land mass, but contain > 50% of earth’s species
55Chapter 6.4 Desert and Tundra Biomes Desert Biomes account for 25% of earth’s surfaceContain only 1% of earth’s biomassReceive little precipitationDesertTundraDid you know that the Arctic Tundra is the world's youngest biome?
56Chapter 6.4 Grasslands Steppe dry, cold, grassland Prairie Grassland Biomes account for 22% of earth’s surfaceContain only 8% of earth’s biomassReceive less precipitation than forest (may have long dry season)Steppedry, cold, grasslandPrairiedominated by herbaceous plants and grasses.Savannatwo very different seasons
57Chapter 6.1 – Quiz (5pts)Red-tailed Hawks feed on chipmunks, what is the chipmunks role in this relationship?What is the Red-tailed Hawk’s roles?If the population of snowshoe hares were to suddenly decline , what would you expect to happen to the lynx population?
58Compare & Contrast Types of Symbiosis Types Alike Different All involve close interaction between two (or more) species.HostPreyCommensalismNo effect+MutualismParasitism-