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Chapter 4. Ecosystems and Communities. The Role of the Climate. What is climate ? The average, year after year conditions of temperature and precipitation in a particular region What is weather ? The day to day condition of the earth’s atmosphere at a particular time and place.
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Chapter 4 Ecosystems and Communities
The Role of the Climate • What is climate? • The average, year after year conditions of temperature and precipitation in a particular region • What is weather? • The day to day condition of the earth’s atmosphere at a particular time and place
What Causes Climate? • The trapping of heat by the atmosphere • The latitude • Winds and ocean current (carry heat) • Amount of precipitation
The Greenhouse Effect • What is the greenhouse effect? • The natural situation in which heat is retained by the layer of greenhouse gases • What are greenhouse gases? • Carbon dioxide, methane, water vapor, and a few other atmospheric gases that trap heat energy and maintain the Earth’s temperature
The Greenhouse Effect Sunlight Some heat escapes into space Greenhouse gases trap some heat Atmosphere
Latitude’s Effect on the Climate • Earth is tilted on its axis so different areas get a a different amount of solar radiation at different times of the year • Differences of latitude and this angle result in 3 main climate zones: Polar, Temperate, and Tropical
The Three Main Climate Zones • Polar Zones • Cold • Located at the North and South Poles • Temperate Zones • Temperature ranges from cold to hot • Located between the polar zones • Tropical Zone • Climate almost always warm • Near equator
Heat Transport in the Biosphere • The Earth is heated unevenly, so this drives winds and ocean currents • The wind and ocean currents help balance this unequal heating
Quiz 4-1 • What are the 3 main climate zones? • What are the main factors that determine climate? • What is the greenhouse effect? Bonus What is the difference between weather and climate?
Biotic and Abiotic Factors • Remember an ecosystem includes all living and nonliving factors • Biotic factors are the living factors in the community example: birds, mushrooms, trees, grass…. • Abiotic Factors are the nonliving factors that shape an ecosystem example: soil, water, sunlight, space, wind….
Shaping an Ecosystem • The biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives • Together these factors determine if an ecosystem is a suitable habitat for an organism
Habitats and Niches • What is a habitat? • The area in which the organism lives which includes the biotic and abiotic factors • Address • What is a niche? • The full range of physical and biological conditions in which an organism lives and the way the organism uses those conditions • Job
Habitat A gopher tortoise needs pine flatwoods with sandy soil Niche A gopher tortoise eats herbaceous plants and creates homes in which other organisms live in Habitat Versus Niche
Habitat Versus Niche • A niche will include all aspects of how that organism interacts and effects the ecosystem in which it lives in • Examples: Its place in the food web, when it reproduces, what biotic and abiotic factors it needs to survive, etc
Niches and Competition • No two species can share the same niche in the same habitat (can have similar niches but not the same) • When this occurs there will be competition
Competition • Competition occurs when organisms (same or different species) attempt to use the same resource at the same time and same place • What is a resource? • Any necessity of life
The lion is competing with the vulture for the carcass The plants are all competing for space, water, sunlight, and nutrients Competition
The Competitive Exclusive Principle • No two species can occupy the same niche at the same time and the same place • If this occurs they will compete until there is a winner and a loser
Types of Relationships in Ecosystems • Predation • Symbiosis • Mutualism • Commensalism • Parasitism
What is Predation? • An interaction in which an organism captures and feeds on another organism • Example: Bear eating a fish
What is Symbiosis? • Any relationship in two species live closely together • 3 main types • Mutualism • Commensalism • Parasitism
Symbiosis • Mutualism- Both Benefit • Example: Bees & flowers, ants and aphids • Commensalism- One Benefits and the other does not benefit • Example: Moss growing on trees • Parasitism- One benefits while the other species is harmed • Example: tapeworm, mosquitoes, fleas
Quiz 4-2 A • What is the difference between an abiotic factor and a biotic factor? • What is a niche? • What happens if two species have the same niche in the same place? (Hint: The Competitive Exclusive Principle) • What are 3 types of symbiosis? Bonus Give an example of mutualism
Ecological Succession • The gradual change in living communities that follows a disturbance • The only thing that is constant is change!
Ecological Succession • A community will gradually change over time through a predictable series of changes until it reaches a “stable” point called the climax community
Ecological Succesion • Two types • Primary Succession • Secondary Succession
Primary Succession • The development of a community that occurs on bare rock or where no soil exists (Volcanic eruptions) • When you start there is no soil • The first species to populate the area are called pioneer species • These are usually lichen
Secondary Succession • The sequential replacement of species that follows a disturbance • Disturbances can include fires, floods, logging, a fallen tree • Disturbance can be good! • Disturbances open up resources for other plants or organisms to use
Importance of Fire in Florida • The majority of Florida is made up of pine forests • Pine trees need lots of light • Disturbances will kill off competing vegetation and allow pine trees to reproduce
Importance of Fire in Florida • Prescribed fires help prevent wildfires • Promotes biodiversity • Kills pests (ticks, etc) • REMEMBER: Fire a natural part of our ecosystem
Biomes • What is a biome? • A group of ecosystems that have the same climate and dominant communities • Organisms are adapted to live in certain biomes
What Creates a Biome? • The climate • The soil • The communities that inhabit it
Organism’s Tolerance • Many organisms are adapted to the conditions of the biome • They have tolerance • Ability to survive and reproduce under conditions that differ from their optimal conditions
The Major Biomes • Tropical rain forest • Tropical dry forest • Tropical savanna • Desert • Temperate grassland • Temperate woodland and shrubland • Temperate forest • Northwestern coniferous forest • Boreal forest • Tundra
Questions? • “No problem can be solved by the same consciousness that created it. We need to see the world anew.” • Albert Einstein
Quiz 4.2B • What is the difference between primary and secondary succession? • What is a pioneer species? • What is tolerance? Bonus Why is fire important to Florida?