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Environmental Science

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Presentation on theme: "Environmental Science"— Presentation transcript:

1 Environmental Science
Unit 2 – Ecological Interactions

2 4.1 Roles of Living Things Objectives
Identify the roles of producers, consumers and decomposers Describe the concept of tropic level.

3 Chapter 4 Role of Living Things
Producers: Photosynthesizing organisms Consumers: any organism that can’t make its own food Herbivore – eats only plants Carnivore – eats only herbivores or other carnivores Omnivores - eats either producers or consumers Scavengers – feed on bodies of dead organisms Levels of consumers : Primary – eats plants Secondary – eats animals that eat plants Tertiary – eat animals that eat animals that eat plants Decomposers: An organism that primarily feeds on dead organisms or the waste from living organisms mainly bacteria and fungi

4 Trophic Levels A layer in the structure of the feeding level of a systems Heterotrophs: eat other organisms Autotrophs: make their own food

5 4.2 Ecosystem Structure Objectives Describe food chains and food webs.
Examine the effects of ecosystem structure on population size and pollution.

6 Chapter 4 Ecosystem Structure
Food Chain: a series of organisms that transfer food between the tropic levels of an ecosystems Food Web: a network of food chains = not simple !

7 Chapter 4 Interconnections
Example: Whales were over hunted Their primary food source (krill) became over abundant. More krill meant more penguins & seals

8 Chapter 4 Diversity and Stability
Which food web represents a more mature ecosystem? Which food web is more stable?

9 Chapter 4 Biological magnification
There are increasing concentrations of pollutants in organisms at higher trophic levels of food webs More

10 4.3 Energy in the Ecosystem
Objectives Investigate the movement of energy through an ecosystem. Define ecological pyramid, and explain its relationship to energy in an ecosystem.

11 Energy and Food Producers 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

12 10% Law 10% 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.

13 Ecological Pyramid Ecological Pyramid is a diagram that shows the relative amounts of energy in different trophic levels in an ecosystem.

14 Biomass Pyramid Ecological Pyramids can show the biomass and numbers (of organisms) as well as energy.

15 4.4 Chemical Cycles Objectives
Describe the chemical composition of the human body. Explain the water cycle, the carbon cycle and the nitrogen cycle.

16 The Human Body 4 elements make up 96% of your body. Oxygen 65% Carbon 18.5% Hydrogen 9.5% Nitrogen 3.5% the rest ~4%

17 The Water Cycle

18 The Carbon Cycle

19 The Nitrogen Cycle

20 Chapter 4 Quiz

21 Chapter 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).

22 Niche refers to a populations role in its ecosystem
Chapter 5.1 Niches Niche refers to a populations role in its ecosystem food habitat reproduction method Species with narrow niches are called specialists (e.g. anteater). Species with broad niches are called generalists (e.g. common crow).

23 Chapter 5.1 Niche influence
includes both Biotic Competitors Predators Decomposers Population Density Abiotic Soil pH Soil Humidity Soil Temperature Air Temperature Wind Speed Sunlight Intensity Soil Nutrients

24 Chapter 5.1 Competitive Exclusion
Crickets Ants Overlapping niches – species can coexist Hawks Owls Both species share the same niche – one will disappear The extinction of a population due to direct competition with another species for resources is

25 Chapter 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.

26 Chapter 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.

27 Chapter 5.2 Evolution Evolution, changes in a population of organisms over time.

28 Chapter 5.2 Evolving to the Niche
Populations evolve by adapting to niches in the environment, dividing available resources (avoiding competition) Specialized species vs. Generalized species

29 Chapter 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 Eucalyptus Ex: Humans

30 Chapter 5.2 Convergent Evolution
Convergent Evolution, is development of similar adaptations in two separate species with similar niches

31 Chapter 5.2 Coevolution Coevolution, species which interact closely and adapt to one-and-other (even predator & prey) - evolve together

32 Chapter 5.3 Populations Unchecked populations growth leads to exponential growth

33 Chapter 5.3 Populations A population’s limit as defined by its ecosystem is its carrying capacity

34 Chapter 5.3 Limiting Factors
Density-independent limiting factors Human Disturbance Climate Natural Disasters Population Size Predation Water Availability Living Space Parisitism Food Competition Disease Density-dependent limiting factors

35 Chapter 5 Quiz

36 Environmental Science
Chapter 6 - Ecosystem Balance

37 Chapter 6.1 Relationships in the Ecosystems
Objectives Explain the relationship size between populations sizes of predator and prey Define symbiosis and state the effects of symbiotic relationships on populations

38 Chapter 6.1 - Predator and Prey
Predator – a consumer that actively hunts and prey – organisms upon which predators feeds

39 Chapter 6.1 - Predator and Prey Population Cycles
The populations of predator and prey are closely linked. Snowshoe hare = Lynx = N1 N2

40 Chapter Parasitism Parasitism – one organism feeds on the tissues or body fluids of another Eyelash Mite Keys to Parasite survival Eat enough to live and reproduce But not so much that you kill your host

41 Chapter Symbiosis Symbiosis – a relationship where two species live together closely. Parasitism is an example of symbiosis. Commensalism One species benefits, and neither helps nor harms the other Mutualism Both species benefits

42 Chapter 6.2 Ecological Succession
Objectives Describe the process of primary and secondary succession Illustrate the evolution of many species from a single ancestor during the process of island succession

43 Chapter 6.2 Ecosystem Successions
Primary Succession Sequence of communities forming in an originally lifeless habitat

44 Chapter 6.2 Lichens Lichens
A fungus and an algae living in a mutualistic relationship Important because able to break down bare rock using stored acid Pioneer community

45 Chapter 6.2 Climax Community
Community that does not undergo further succession

46 Chapter 6.2 Secondary Community
Succession that occurs when a community has been cleared by a disturbance, but does not disturb the soil

47 Chapter 6.2 – Other Successions
Aquatic Such as what might happen in an oxbow lake Island succesion, birds often populate unfilled niches. Darwin’s Finches

48 Chapter 6.3 Balance in the Ecosystem
Objectives Examine 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.

49 Chapter 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

50 Chapter 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 Balance VOID

51 Chapter 6.3 Balance Cause/Effect
Extinction of dinosaurs Rapid evolution of mammals

52 Define the concept of a biome and name the eight major biomes.
Chapter 6.4 Land Biomes Objectives Define the concept of a biome and name the eight major biomes. Illustrate where each of the eight major biomes occurs.

53 Chapter 6.4 Biomes Biome a major type of ecosystem with distinct temperature, rainfall & organisms

54 Forest Biomes account for 75% of earth’s biomass
Chapter 6.4 Forest Biomes Forest Biomes account for 75% of earth’s biomass Receive abundant precipitation Coniferous (sometimes refered to as ‘taiga’) Deciduous four distinct seasons, spring, summer, autumn, and winter. Rain Only account for 6% of earth’s land mass, but contain > 50% of earth’s species

55 Chapter 6.4 Desert and Tundra Biomes
Desert Biomes account for 25% of earth’s surface Contain only 1% of earth’s biomass Receive little precipitation Desert Tundra Did you know that the Arctic Tundra is the world's youngest biome?

56 Chapter 6.4 Grasslands Steppe dry, cold, grassland Prairie
Grassland Biomes account for 22% of earth’s surface Contain only 8% of earth’s biomass Receive less precipitation than forest (may have long dry season) Steppe dry, cold, grassland Prairie dominated by herbaceous plants and grasses. Savanna two very different seasons

57 Chapter 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?

58 Compare & Contrast Types of Symbiosis Types Alike Different
All involve close interaction between two (or more) species. Host Prey Commensalism No effect + Mutualism Parasitism -

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