Download Parasitism

Ecology Unit
Chapter 17
Biological Communities
Interactions w/ defenses
• Herbivores protection – production of
defensive chemicals
• Ex. Production of mustard oil which is toxic
to most insects.
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Caterpillars of the cabbage butterflies are
the only insects than can eat plants of the
mustard family b/c they have evolved the
ability to break down mustard oils into
harmless chemicals.
Symbiosis
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Mutualism
Commensalism
Parasitism
Predation
Competition
Mutualism
Both organisms benefit from the activity of
each other
• Ex. Ant/Acacia Tree
– The ant keeps predators away from the acacia tree
– The acacia provides shelter and food for the ant
• Ex. Ant / Aphid (pg 364)
– many ants are found in the vicinity of aphids. The ants feed on
the sugary fluid released by the aphids, and the aphids are
protected by the ants
• In some cases the organisms must live together to survive.
– EX. Protists living inside a termite
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Protists – digest the cellulose from wood
(food & habitat)
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Termite - gets digested wood
(food)
Mutualism
Tiny fig wasps
reproduce inside
unripe figs wasps and
fig trees cannot
reproduce without the
wasps.
The crocodile bird cleans the
teeth of the crocodile which
will open his mouth for the bird.
In return the crocodile provides
protection for the bird.
Plants & Bees
Plants provide food
Bees help pollinate
Commensalism
• one organism benefits and the other
organism is neither harmed nor does it
benefit
– Ex. Clown fish /Sea Anemones
– Ex. Barnacles / Whales
– Ex. Remora fish / Sharks
Commensalism
Remora fish
(gets food & protection)
&
Shark
Clown fish
(protection)
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Sea Anemones
Barnacles
(habitat & protection)
&
Whales
Parasitism
• Parasitism – one organism (the parasite)
benefits at the expense of the other (the host).
The host is harmed in some way.
• Usually the parasite will not kill its host
EXAMPLES
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Mosquito on an animal
Tape worm in an animal
Tick on an animal
Mistletoe on a tree
Lice on an animal
Parasitism
Mosquito
(parasite)
&
Human arm
(host)
Mistletoe
(parasite)
on
Tree
(host)
Lamprey
(parasite)
on
A larger fish
Tick
(parasite)
Predation
• Predation – one organism (the predator)
benefits by killing the other (the prey) for
food.
– Lions eating zebras
– Snakes eating mice
– Spides eating insects
Predators
Section 2
how competition shapes communities
• Competition – both organisms have the
same needs or requirements. These could
be for food, space, territory or mates. This
may involve the same species (intraspecific competition) or different species
(inter-specific competition). For example:
sponges competing for space with corals.
• Niche – how an organism lives the “job”
– What it eats
– When it eats
– Where it eats
• Do NOT confuse niche with habitat !
• Fundamental niche
– Entire range of resource opportunities an organisms potentially
has available
• Realized niche
– Actual part of the fundamental niche that the organism occupies
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G.F. Gause proved that two competitors
CANNOT coexist on the same LIMITED resources.
This demonstrates the principle of COMPETITIVE
EXCLUSION
Major Biological Communities
• Biome – major biological community that
occurs over a large area of land
• Two most important abiotic factors that
affect a biome
• TEMPERATURE
• MOISTURE
Terrestrial Biomes
1. Tropical Rain Forest
2. Temperate Grasslands
3. Temperate Deciduous Forest
4. Temperate Evergreen Forest
5. Desert
6. Savannas
7. Taiga
8. Tundra
Tropical Rain Forest
• Lush vegetation,abundant rain, and uear-round warm
temperatures
• Most rainfall of any biome on Earth
• Avg. of 180in/year (rains every day)
• Richest biome in term of species diversity
• Poor soil quality Soil contains few nutrients
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Most nutrients are inside the plants
not the in the soil
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Most animals live in trees or on the
vegetation
Relation to equator
• Closer an area is to the equator, the
greater the diversity of species.
– Longer growing season
– greater diversity
– Warmer temperatures
– Greater rain fall
• Tropical Rain forest lies the closest to the
equator
• Tundra lies the farthest away
Savannas
• The world’s great dry grasslands.
• Low annual precipitation / Seasonal rainfall
• Prolonged annual dry seasons /Seasonal
drought
• 35 to 60 in rain/year
• Open, widely spaced trees
• Herds of grazing animals
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elephants, giraffes, lions
Tundra
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Located between the taiga & North Pole.
Covers 1/5 of the Earth’s land surface
Low annual precipitation
Water – usually unavailable most of the year b/c it is frozen
Permafrost – main characteristic of the tundra
Permafrost – thick, continually frozen layer of ground in the
northern tundra
Few large trees – permafrost restricts root development
Does have summer and a winter season
Summer – short ( plants must be able to grow & mature quickly)
Animals – Penguins, foxes, caribou, polar bears, mosquitoes
Taiga
• Winters – long, cold,
• Summer - wet climate / moderate temp
• Coniferous trees are the predominate
trees ( cone bearing)
• Northern Forest
• One of the largest land biomes on Earth
Desert
• Driest biome on Earth
• Less than 10in rain/year
• Most extensive in the interiors of
continents
• Vegetation is sparse (not much)
• Animals – mainly reptiles/active at night
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dry scaly skin to help prevent water loss
lay amniotic eggs – help prevent water loss
Temperate Grasslands
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Highly productive for agriculture
Soil is fertile
Bread basket of the world
Also have herds of grassing animals
Nebraska Kansas
Temperate Deciduous Forest
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Mild climate / plentiful rain
Warm summers / cold winters
Eastern United States
Trees are generally hardwoods (oak,
hickory and beech)
Temperate Evergreen Forests
• Southeastern and western United States
• Pine trees are predominate
Aquatic Biomes
• Two main aquatic biomes
– Freshwater
– Marine
• Estuary – area between. Where sea
water and fresh water mix.
Freshwater
• Lakes / Ponds / Streams / Rivers
• Ponds & lakes have three zones.
– Littoral – shallow – near shore (photosynthetic
organisms)
– Limnetic – close to surface but farther away
from the shore
– Profundal – deep water zone (bottom feeders)
Marine Biome
• Nearly ¾ of the earth’s surface is
covered by ocean. Almost all of the
earth’s surface water is contained in
ocean ecosystem
–Intertidal Zone
–Open sea surface
–Deep ocean
Marine (Ocean)
• Shallow (intertidal zone)
– Greatest diversity in ocean
– Location of the world’s greatest
fisheries
– Nutrients wash out from the land
Marine
Surface of open sea
• Apx. 40 % of the earth’s
photosynthesis occurs in this
region
• Plankton – found in this region
Deep Ocean
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Deepest waters of the sea
Greatest diversity on ocean organisms
Marine communities live in total darkness
NO light
Organisms with light-producing bosy parts
are found in this region
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Great squids / angle fish
Intertidal
Shallow
Surface
Deep
Deep
Surface
Surface
Estuary
Area between fresh & ocean water