Download Chapter 4 Ecosystems and Communities

Chapter 4
Ecosystems and Communities
4.1 Climate
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Weather:
Is the day-to-day conditions of Earth’s atmosphere.
Climate:
Average conditions over a long period of time.
What is the climate and weather of Southern
California?
Solar Energy and the Greenhouse
Effect
 All the carbon dioxide builds up in the Earth’s
atmosphere, trapping heat.
 Greenhouse effect:
 Natural process that stops all sun’s heat from escaping
rapidly back to space.
 Without the green house
effect the Earth would be
30 C cooler.
 The Earth’s surface can be divided into different
temperate zones based on lines of latitude.
 We have 3 different zones….
 Tropics:
 Warmest temperature zone
 Polar zones:
 Coldest temperature zone
 Temperate zone:
 Seasonal changes.
What zone do we live in?
 Temperate zone
4.2 Niches and Community
Interactions
 Why does a crab live in the ocean?
 Why does a lion live in the Savanna?
 They are all adapted to live in certain places.
 Tolerance:
 The ability to survive and reproduce under a range of
environmental circumstances.
 Habitat:
 General place where an organism lives.
Niche
 Niche:
 Describes not only what an organism does, but also
how it interacts with biotic and abiotic factors in the
environment.
 It’s an organisms job.
 Resources:
 Any necessity of life, such as water, nutrients, light,
food, or space.
 What is a plant’s niche?
 Photosynthesis and give us oxygen.
 What is your niche?
 Get good grades…etc
 If two people want the same job, what happens?
 If there is limited food, what will the two species do?
 Compete!
 Competitive exclusion:
 If two species are similar in their requirements that the
same resource limits both species growth, one species
may succeed over the other.
Predation, Herbivory, and Keystone
Species
 Predation:
 An interaction in which one animal (the predator)
captures and feeds on another animal (the prey).
 Herbivory:
 An interaction in which one animal (the herbivore)
feeds on producers (such as plants).
 We have a food chain with sea otters, sea urchins, and
kelp. What would happen to the environment if the
sea otters died off?
 Sea urchin population would increase, while the kelp
would decrease.
 The sea otter would be considered the keystone
specie.
 Keystone specie:
 Can cause dramatic changes in the structure of a
community.
Symbiosis
What kind of people do you interact
with?
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Friends
Parents
Teammates
Teachers
Coaches
Boyfriend/Girlfriend
What kind of relationships do you
have with them?
Story
 In terms of Gary and I, what kind of relationship did we
have?
 +,- In terms of Nicole and I, what kind of relationship do we
have?
 +,+
What kind of relationship do these
organisms have?
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Human
___
Mosquito
+
What kind of relationship do these
organisms have?
 Black billed Magpie
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 American Bison
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Why does the tortoise have a neutral relationship
while the rodent and frog are positive?
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Gopher Tortoise
0
Rodent
+
Frog
+
 These reflect different levels of symbiosis.
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Symbiosis:
When two species live closely together.
There are three main classes of symbiotic relationships.
Mutualism
Parasitism
Commensalism
Symbiotic Relationships
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Parasitism:
One organisms benefits, other is harmed.
Mutualism:
Both organisms benefit
Commensalism:
One organisms benefits, the other is neither harmed
or benefited
Parasitism
Commensalism
Mutualism
4.3 Succession
 Ecological Succession:
 Series of more-or-less predictable changes that occur in
a community over time.
 Ecosystems change over time, especially after
disturbances, as some species die out and new species
move in.
 Primary succession:
 Area with no remnants of an older community.
 Pioneer species:
 The first species to colonize barren areas.
 Secondary succession:
 When disturbances damages an existing community but
leaves soil intact.
Primary Succession
Succession
Secondary Succession 1 Year
Secondary Succession 5 years
Secondary Succession 10 years
Secondary Succession 25 years
Secondary Succession 30 years
Human Caused Disturbances
 What is happening to trees and forests?
 Deforestation:
 Clearing of forests for agriculture.
4.4 Biomes
 What do you think about when you hear California?
 What do you think about when you hear Antarctica?
 Biomes:
 Defined by abiotic factors like climate and soil type,
and biotic factors like plant and animal life.
Examples of Biomes
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Tropical Rainforest
Tropical Dry Forest
Tropical Grassland/Savanna/Shrubland
Desert
Temperate Grassland
Temperate Woodland and Shrubland
Temperate Forest
Northwestern Coniferous Forest
Boreal Forest
Tundra
Tropical Rainforest
 Warm temperatures, has the most biodiversity and
rainfall.
 Tall trees form a dense, leafy covering called the
canopy.
 Shorter trees form the understory.
Tropical
Grassland/Savanna/Shrubland
 Warm; seasonal rainfall; compact soils; frequent fires
set by lightning.
 Migratory animals such as rhinos and elephants.
Desert
 Least amount of precipitation.
 Undergo extreme daily temperature changes. Hot
and cold.
 Cacti are adapted to store water.
Temperate Grassland
 Fertile soils, warm and hot summers, cold winters,
and occasional fires.
Temperate Forest
 Deciduous trees:
 Plants that shed their leaves during a particular
season.
 Coniferous trees:
 Produce seed-bearing cones.
 Cold winters, warm summers, year round
precipitation.
Boreal Forest (Taiga)
 Dense coniferous forests, winters are bitterly cold.
Tundra
 Permafrost:
 Permanently frozen subsoil.
 Strong winds, low precipitation, long cold dark
winters.
 Not a lot of biodiversity
4.5 Aquatic Ecosystems
 What factors affect life in aquatic ecosystems?
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Water depth
Temperature
Flow
Amount of dissolved nutrients
 Who has been to the beach?
 What happens to the water color when you get step
out to the ocean?
Water Depth
 Light areas (photic zone)= light penetrates the water
 Dark areas (aphotic zone) = limited light
 Can plants live in the aphotic zone?
 No, they cannot photosynthesize.
 Benthos:
 Organisms that live in the benthic (shallow) zone.
Deep Sea Creatures
Freshwater Ecosystems
 Can be divided into three main categories
 1. Rivers and Streams
 2. Lakes an Ponds
 3. Freshwater Wetlands
Rivers and Streams
 Originate from underground water sources in
mountains or hills.
 Many animals depend on rivers and streams for food.
Lakes and Ponds
 Food webs in lakes and ponds often are based on a
combination of plankton and attached algae and
plants.
 Plankton:
 Includes phytoplankton (plant) and zooplankton
(animal).
Freshwater Wetlands
 Wetlands:
 Is an ecosystem in which water either covers the soil
or is present at or near the surface for at least part of
the year.
 Nutrient rich, highly productive, and serve as
breeding grounds for many organisms.
 Purify water by filtering pollutants and help prevent
flooding.
Estuaries
 Estuaries:
 Streams and rivers merge with an ocean.
 Chesapeake bay!
Estuaries
 Serve as spawning and nursery grounds for many
ecologically and commercially important fish and
shellfish.
Marine Ecosystems
 Ecologists divide the ocean into three zones based on
depth and distance from shore.
Ocean zones
 Intertidal zone:
 Area of shore between the high-tide and low-tide
lines. Exposed to sun. (closest to land)
 Coastal zone:
 Low-tide out the edge of continental shelf. Some
sunlight. (in between ocean and land)
 Open Ocean zone:
 90% of the world ocean area. Filled with zooplankton.
(farthest away from land)