intro to ecology notes
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Intro to Ecology Notes. QQ#1: What is Ecology?. What is Ecology?. The study of interactions among organisms and between organism and their environment, or surroundings. Basically… Why animals are where they are and how they interact. Levels of Organization. - PowerPoint PPT PresentationTRANSCRIPT
Intro to Ecology Notes
QQ#1: What is Ecology?
What is Ecology?▪ The study of
interactions among organisms and between organism and their environment, or surroundings.
▪ Basically…– Why animals are where
they are and how they interact.
Levels of Organization▪ To understand these
relationships within the biosphere, scientists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere.
QQ#2: What is a species?
Levels of Organization
▪ Species: a group of organisms so similar to one another that they can breed and produce fertile offspring
Levels of Organization▪ Populations: Groups
of individual of the same species that live in the same area
Levels of Organization▪ Communities: two or
more populations that live in a defined area.
QQ#3: What is an ecosystem?
Levels of Organization▪ Ecosystems: collection
of all the organisms that live in a particular place, together with their nonliving, or physical, environment
Levels of Organization▪ Biome: group of ecosystems that have the same
climate and similar dominant communities
What Shapes an Ecosystem?
Biotic and Abiotic FactorsNiche
Community InteractionsSuccessions
Biotic and Abiotic Factors◊ Biotic factors:
• Biological influences on organisms within an ecosystem
• Living or once-living◊ Abiotic Factors:
• physical factors that shape an ecosystem
• Non-living
BIOTIC ABIOTIC
QQ#4: What are some examples of biotic factors? abiotic factors?
Biotic and Abiotic Factors◊ Examples of Biotic
factors:• Plants and animals• Aquatic (water)• Benthic (bottom-
dwelling)• Terrestrial (land)
◊ Examples of Abiotic Factors:
•Temperature•Water •Sunlight •Salinity - amount of dissolved salt
•Wind, rocks and soil•Catastrophes - earthquakes, fires, floods, landslides, toxic spills
Biotic and Abiotic Factors◊ Biotic and abiotic factors
determine the growth and survival of an organism
◊ Also determine the productivity of the ecosystem in which an organism lives
◊ Habitat: area where an organisms lives (biotic and abiotic included)
Niche◊ Niche: the full range of physical
and biological conditions in which an organism lives and the way the organism uses those conditions.• Place in the food web
◊ Food it eats, how it obtains it, etc.• Physical conditions needed to survive
◊ Temperatures it can survive in
Niche◊ No two species can share the same
niche in the same habitat.◊ Can occupy different niches that are
very similar.
Community Interactions◊ Organisms that live together in
ecological communities constantly interact.• Competition• Predation• Symbiosis
◊ All affect an ecosystem
Competition◊ Occurs when organisms of the
same or different species attempt to use a resource at the same place and time.• Resource: any necessity of life (water,
food, light, space, etc.)
Competition◊ Direct
competition• Results in a
winner and a loser• Losing organism
fails to survive.
QQ#5
◊ A bear catches and eats a fish for food.
◊ Who benefits?◊ Who doesn’t?
Predation◊ An interaction in
which one organism captures and feeds on another organism
◊ Predator: the one that does the killing/eating
◊ Prey: the one being eaten
Symbiosis◊ Any relationship in which two
organisms live closely together• Means “living together”
◊ 3 Main classes in nature:• Mutualism• Commensalism• Parasitism
QQ#6◊ The ant cares for
the aphids and protects them from predators. The aphids produce a sweet liquid that the ant drinks.
◊ Who benefits? Who doesn’t?
Mutualism◊ Both species
benefit from the relationship
Clownfish and Sea Anemone
Bee and Flower
QQ#7◊ The orchid benefits from its perch
in the tree as it absorbs water and minerals from rainwater and runoff.
◊ Who benefits? Who doesn’t?
Commensalism◊ One member in
the relationship benefits, while the other is neither helped nor harmed.
Barnacles and Whales
QQ#8
◊ A tick feeds on the blood of its host and may also carry disease-causing microorganisms.
◊ Who benefits? Who doesn’t?
Parasitism◊ One organism lives
on or inside another organisms and harms it.
◊ Parasite obtains all or part of its nutritional needs from the host
◊ Generally weakens but does not kill their host a tomato hornworm is covered
with cocoons of pupating braconid wasp
Ecological Succession◊ Ecosystems are constantly
changing due to natural or human disturbances.
◊ Older inhabitants gradually die out and new organisms move in, causing changes in the community.
Ecological Succession◊ Ecological Succession: series of
predictable changes that occur in a community over time.
◊ Succession may result from:• Slow changes in physical environment• Sudden disturbance from human
activities
Primary Succession◊ Occurs on surface
where no soil exists.• Where lava rock is
from volcanic explosion
• On rock exposed when glaciers melt
Primary Succession◊ Pioneer species: first species to populate
the area◊ On volcanic rock, often lichens (fungus
and aglae that can grow on bare rock)• When they die, add organic material to help
form soil for plants to grow.
Secondary Succession◊ When the natural or human
disturbance is over, community interactions tend to restore the ecosystem to its original conditions.
Succession in a Marine Ecosystem
◊ Occurs when a large whale dies and sinks to the bottom.
◊ Attracts scavengers and decomposers.◊ Decomposition of body enriches surrounding
sediments.◊ Heterotrophic bacteria decompose oils in bone that
release chemical compounds that serve as energy sources.