Field Ecology Climate Terrestrial Biodiversity Biomes Biomes.
Ecology Chapter 2: Principles of EcologyPrinciples of Ecology Chapter 3: Communities and...
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Transcript of Ecology Chapter 2: Principles of EcologyPrinciples of Ecology Chapter 3: Communities and...
Ecology
Chapter 2: Principles of Ecology
Chapter 3: Communities and Biomes
Principles of Ecology
2-1: Organisms and Environment
2-2: Nutrition and Energy Flow
Communities and Biomes
3-1: Communities
3-2: Biomes
2-1: Organisms & the Environment
• Ecology: study of interactions between organisms and their environment
• Explains how organisms affect each other and the world they live in
• Environment can either be living or non-living
Non- living Environment• Abiotic factors: the non-living parts of
an organism’s environment
• Examples include air currents, temperature, moisture, light, and soil.
Living Environment• Biotic factors: all the living organisms
that inhabit an environment
• All organisms depend on others directly or indirectly
Abiotic or Biotic?
Biotic
Abiotic or Biotic?
Abiotic
Levels of Organization• All organisms are organized into levels
cells
organismorgan
systems
organs
tissues
• The interactions of the organism are then organized depending on complexity
1st Level • Organism
– individual living thing that is made of cells, uses energy, reproduces, responds, grows, and develops
– at this level species are studied•species: group of similar organisms that
can interbreed and produce fertile offspring
2nd Level • Population
– A group of organisms that interbreed and live in the same place at the same time
– Have to be same species to be a population
3rd Level
• Community– all the interacting
populations in a certain area at a certain time
– change in one population may cause changes in the other populations Ex. hawks and mice
4th Level
• Ecosystem– interacting
populations in a community and the community’s abiotic factors
– terrestrial or aquatic– subject to change
Ex. forest, compost heap, pond
5th Level
• Biosphere– the portion of Earth
that supports life– extends from high
atmosphere to bottom of oceans
Organism
Community
Ecosystem
Population
Biosphere
Organisms in Their Environment
• Habitat: place where an organism lives out its life– Ex. bottom of a stream
• Niche: all strategies and adaptations a species uses in its environment– organism’s way of life
Relationships
• Predation– predator seeks
out and eats prey• Ex. cheetah
hunting down antelope
– constant battle for survival
preypredator
Relationships
• Symbiosis– close and
permanent association between organisms of different species
– they live together– helps maintain
their survival– 3 types of
symbiosis
Symbiosis
• Mutualism– symbiotic
relationship where both species benefit
– Ex. Ants and Acacia Trees
Symbiosis
• Commensalism– symbiotic
relationship where one species benefits and the other is neither harmed nor benefited
– Ex. Clownfish and Sea Anemones
Symbiosis
• Parasitism– symbiotic
relationship where one species benefits at the expense of the other
– species that is harmed is called a host
– Ex. Fleas and Animals
2-2: Nutrition & Energy Flow
• ultimate source of energy for all life (directly or indirectly) is the sun
• some convert sunlight into energy--• an organism that
uses light energy to make their own food is a producer or autotroph
plants
Obtaining Energy
• Producers then feed consumers– organism that cannot make its own food
and feeds on other organisms; also called heterotroph
• Heterotrophs can be carnivores
herbivoresor
omnivores
Food Chains
• Matter and energy move through ecosystems from producers to consumers
• Some energy is also transferred to the environment as heat
• Food chain:– model showing how matter and energy
move through an ecosystem– Nutrients and energy move fromAutotrop
hHeterotroph Decompose
r
Food Chains
• Arrows indicate direction energy is transferred
• Each organism represents a trophic level or a feeding step
• First level is always a producer• Remaining levels are
consumers and can be divided into different orders
Consumers Can Be:
• 1st order heterotroph (primary consumers):
•feeds on plants•grasshoppers, deer, mice
• 2nd order heterotroph (secondary consumers):
•feeds on 1st order heterotroph•frogs, snakes, small birds, etc.
• 3rd order heterotroph (tertiary consumers):
•feeds on 2nd order heterotroph•owls, coyotes, snakes, etc.
Food Webs
• Food chains only show one route of matter and energy transfer
• Ecosystems typically have more than one route– Ex. Snakes eat mice that eat producers,
but also eat frogs that eat 1st order consumers. So what is the snake, and how is energy transferred?
• Food web: shows all the possible feeding relationships at each trophic level in a community
Food Webs
• Represents a network of interconnected food chains
Ecological Pyramids
• another way to show how energy flows
• Energy pyramids show:– Only 10% of energy is available to
next level– large # of producers to support small # of primary consumers– large # of primary consumers to support small # of secondary consumers
100%
0.1%
1%
10%
Cycles in Nature
• Matter is also transferred; does not disappear but is constantly cycled
• Three main elements that must move through an ecosystem are:– Water– Carbon– Nitrogen
Water Cycle
Carbon Cycle
Nitrogen Cycle
3-1: Communities• What is a community?
– all the populations in a certain area at a certain time
• Are all parts of the world suitable for every organism?– No
Limiting Factors
• any factor that restricts the number of individuals in a population
• affects an organism’s ability to survive in its environment
• Examples:
waterfood predator
s
temperature
space sunlight
soil
Tolerance
• range of factors under which an organism functions & survives
Organisms absent
Organisms infrequent
Greatest number of organisms
Organisms infrequent
Organisms absent
Zone of intolerance
Zone of physiological
stress
Optimum range
Zone of physiological
stress
Zone of intolerance
Range of tolerance
Pop
ulat
ion
Lower limit Upper limit
Succession
• orderly, natural changes and species replacements that occur in communities over time
• occurs in stages; different species may be present at each stage
• 2 types– primary– secondary
Succession
• Primary– colonization of barren land by communities
of organisms– takes place where there are no living
organisms– first species to take hold are pioneer
species– Example
• Lava destroys everything and forms new land• Lichen begins growing—pioneer species
Succession
• Secondary– takes place after an existing community
is disrupted in some way– occurs in areas that previously
contained life and on land that still contains soil
– Example• Forest fires destroy communities, but soil is
still available• Species begin coming back
• After some time, succession slows down and the community becomes fairly stable
• Climax community– stable mature community that undergoes
little or no change
3-2: Biomes• large group of ecosystems that share
similar climates and organisms• terrestrial or aquatic
Aquatic Biomes• Marine biomes
– 4 marine groups•Estuaries•Intertidal zones•Photic zones•Aphotic zones
• Freshwater biomes
Estuaries
• occur where rivers join oceans and freshwater mixes with salt water
• salinity can change allowing a wide range of organisms to live here
• most are used as “nurseries”
• Organisms include:– snails, crabs, shrimp,
clams, fishes, birds, grasses
Intertidal Zone
• portion of shoreline lying between high and low tide zones
• changing oxygen and nutrient levels
• crashing waves• organisms include
snails, sea stars, barnacles, clams, crabs
Photic Zone• portion of marine biome shallow
enough for sunlight to penetrate• many diverse species• plankton is abundant (small organisms
that drift and float in photic zone)• includes corals, fishes,
sea plants, etc.
Aphotic Zone
• portion of marine biome where light does not penetrate
• organisms include crabs, squids, octopi, fishes, etc.
Freshwater Biomes• ponds, lakes, rivers,
streams• includes organisms
that not only live in the water but those that go on land as well
• organisms include frogs, snails, fish, turtles, plants, etc.
Terrestrial Biomes
• Think about traveling from north pole to equator—what changes would you observe? Why?
• Latitude describes north-south position from equator
• Latitude and climate are directly related
• Latitude affects climate (temperature, precipitation, etc.)
• Small differences in temp. and precip. can create different biomes
Tundra
• treeless land with long summer days and short period of winter sunlight
• temperatures barely rise above freezing
• permafrost—permanently frozen layer of ground
• soil contains little nutrients• little to no precipitation
Taiga
• also called boreal forest• made mostly of coniferous trees—fir,
spruce, hemlock—with poor acidic topsoil
• weather is harsh, but milder than tundra• cold winters, little precipitation• more organisms
than tundra
Desert
• arid region with little to almost no plant life
• driest biome; less than 23 cm precip/year
• temperatures can be extremely high or extremely cold
• vegetation varies depending on rainfall
Grassland• large communities
covered with rich soil and grasses
• have more rain than deserts, but not enough to support tree growth
• increased diversity• also called prairies,
steppes, and pampas
• Savannas are like grasslands, but receive enough rain to support trees
American Buffalo
Temperate Forest
• deciduous forests with broad-leaved hardwood trees; 70-150 cm of precip/yr
• in temperate zone—goes through seasons
Rain Forests
• forests receiving extensive amounts of rainfall; at least 200 cm/yr
• can be temperate or tropical• Tropical
– warm weather, wet weather, lush plant growth
– near equator– greatest biodiversity– poor soil; nutrients recycled quickly