intro to ecology notes qq#1: what is ecology?. what is ecology? ▪the study of interactions among...
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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▪ 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.