Transcript ECOLOGICAL PRINCIPLES

ECOLOGICAL
PRINCIPLES
Concept 1
Ecology
BIOSPHERE
a thin blanket of life surrounding the
earth which arises when atmosphere,
land and sea meet
– most fragile layer of the earth
– 10 miles thick (5 miles up into
atmosphere, 5 miles down into ocean)
– ecosystems exist within the biosphere
Arrangement of the Biosphere
COMPONENTS OF A BIOME
Biomes are large geographic areas
defined by:
-climate (temp, rainfall…)
-soil type
-type of plants
?
(plants determine animals)
Which division of the biosphere
contains all other divisions?
Question?
From looking at the diagram, formulate
your own definition of community!
…hint…Think about what is included and
what is not included
Ten Major Biomes
Biome
Precipitation
Temperature
Soil
Diversity
Trees
Grasses
Tropical Rain Forest high
hot
poor
high
dense
sparse
Tropical Dry Forest
mild
rich
moderate
medium
medium
mild
variable
summer hot
clay
poor
rich
moderate
moderate
moderate
sparse
sparse
absent
dense
sparse
dense
Temperate woodland summer low,
summer hot
and Shrubland
winter moderate
poor
low
medium
medium
variable
Tropical Savanna
variable
Desert
low
Temperate Grassland moderate
Temperate Forest
moderate
summer moderate, rich
winter cold
high
dense
sparse
Northwestern
Coniferous Forest
Boreal Forest
high
rocky, acidic
low
dense
sparse
poor, acidic
moderate
dense
sparse
Tundra
low
summer mild,
winter cold
summer mild,
winter cool
summer mild,
winter cold
poor
low
absent
medium
moderate
This is not in your notes because
it would not copy well!!!
Biome terms
• Diversity-number of different kinds of
living and non-living “things”
• Temperate-distinct seasons
• Tropical-consistently warm
• Deciduous-plants shed leaves
• Coniferous-leaves are year round
Question?
What is the biome description here at
Central Dauphin?
• ECOSYSTEM: a place where
relationships between biotic and
abiotic factors are affected by
geology and climate
– energy is processed through the biotic
components
– interrelationships create stability
– populations are the basis of ecosystems
• BIOTIC: living organisms (plants and
animals)
• ABIOTIC: non-living (water, minerals,
soil…)
• POPULATION: the number of organisms
of the same species
• SPECIES: organisms that can interbreed
and produce fertile offspring
?
Microclimates
HABITATS
• small subdivisions of an ecosystem
where biotic components live and
acquire the basic requirements of life
• must include essential abiotic
components
• BASIC REQIREMENTS: food,
shelter, water, space, air
Habitat is the ADDRESS
• varies in size
• habitats overlap between different
species
• varieties of habitats increase
diversity
• BIODIVERSITY: number of
different kinds of organisms within
the ecosystem
DIVERSITY = STABILITY
• survival of the ecosystem is
dependent on its diversity
?
• the greater the diversity, the more
likely an ecosystem could survive a
cataclysmic event (like an extinction,
volcano…)
EDGES ARE VERY STABLE
• the edge habitat (place where 2
habitats overlap) has the greatest
diversity of plants and animals
• edge is usually more stable than
either of the 2 habitats it divides
• edge shares species from both
habitats as well as supporting edge
only species
This is not in
your notes!
This is not in
your notes!
Concept 2
Population Dynamics
POPULATION DYNAMICS
• Explains how wild populations control and
maintain themselves
• Based on the idea that resources are
limited (CARRYING CAPACITY)
• All species (plants and animals) must have
the BASIC REQUIREMENTS OF LIFE
– -FOOD, SHELTER, WATER, SPACE, AIR
– AND OF COURSE THE RIGHT CLIMATE
POPULATIONS
• Members of the same species
• Populations are limited in “range” by
habitat, geology, climate and limiting
factors within their habitat
• Tends to be maintained within the
carrying capacity and critical number
LIMITING FACTORS
•
something that maintains population
size within the habitats carrying
capacity
1.
2.
3.
4.
5.
6.
Food
7. Climate
Competition
8. Disease
Predation
Geology/geography/topography
Human influences
Lack of any requirement of life
Carrying Capacity
• CARRYING CAPACITY: the number
of organisms of a species that a
habitat can support (provide basic
requirements)
Example: The pond can support 25
frogs. What may limit the number of
frogs?
Consequences
• breaking the carrying capacity will
cause collapse of the population
• may lead to extinction
• may reduce gene pool
• may just reduce numbers long enough
for the habitat to recover
Can Carrying Capacity Change?
• Yes
• Increases with habitat improvement
– Decrease in abusive population
– Better weather promoting good food
• Decreases with habitat destruction
– Increase in populations above carrying
capacity
– Cataclysmic event (volcano)
– Changes in climate (global warming?)
Critical Number
• The lowest number a species can drop
to in an ecosystem and still recover
– Set by nature to maintain genetic
diversity
– Prevents in-breeding and passing on “bad
genes”
Populations may stabilize
• Stable populations will fluctuate
between the carrying capacity and
the critical number.
• Most species with proper limiting
factors will function along these lines
• This is called DYNAMIC
EQUILIBRIUM
• These are called S-Curve populations
Draw your own in your notes!!!
S-curve Populations
NUMBER
Carrying
Capacity
Critical
Number
TIME
causes of stabilization
•
•
•
•
•
•
Emigration
Immigration
Death
birth
predator-prey
disease
These are
limiting factors!
J-curve Populations
• Are not stable populations
• Usually crash after they break carrying
capacity
• Due to lack of limiting factors or it has a
special reproductive strategy
– -many young with lack of parental care such as
fish
• May be an invasive species (gypsy moth)
Draw your own in your notes!!!
J-curve Populations
NUMBER
Carrying
Capacity
Recovery
Critical
Number
TIME
Extinction
Species Interact with each other
to maintain energy and population
balances
• Predator-Prey relationships
Predators and Prey regulate each others populations
?
• Competition
-attempt to use the same
limited resources
-limits population size
between competitors
Categories of Competition
• Interspecific:
• Intraspecific:
competition between
2 or more species
for a single
resource
competition between
members of the
same species
-usually for mates
or nesting habitat
or territory
Interspecific competition
shows
competition
can be
Figure 4-5
Threehow
Species
of
and(RESOURCE
Their NichesPARTITIONING).
avoided by sharingWarblers
resources
Section 4-2
This guarantees
that all species survive and increase
diversity
Cape May Warbler
Feeds at the tips of branches
near the top of the tree
Bay-Breasted Warbler
Feeds in the middle
part of the tree
Spruce tree
Go to
Section:
Yellow-Rumped Warbler
Feeds in the lower part of the tree and
at the bases of the middle branches
• Parasitism
-lives on or in a
host species
-often host
specific
-generally causes
harm or death of
host in extreme
situations
• Mutualism
-both organisms
will benefit from
the arrangement
-symbiosis arises
through
coevolution
• Commensalism
– one member of the relationship benefits
– one member of the relationship gains
nothing, but is not harmed
example: lichens growing on the tree
benefit from the tree, but the tree is
not harmed or helped by the lichen
Concept 3
Flow of Energy
FLOW OF ENERGY
Energy is processed
Feedback
input energy
ecosystem
output energy
-this allows the ecosystem to maintain an
energy balance
NICHE = JOB
• the way an organism makes a living in
their habitat
• niche describes how the organism
gets it energy
– producer (autotrophs and herbivores)
– consumer (carnivores, scavengers)
– decomposers
NICHE
WHAT THEY EAT
TYPES OF ORGANISMS
Autotroph
Sunshine—these
organisms make their own
food
Plants (the green guys)
Herbivore
Plants
Bunnies, deer, bees
Carnivore
other animals-general
term
Lions, anteaters, fox, bass
Predator
Hunts, kills, eats other
animals
Lions, anteaters, fox, bass
Parasite
Lives on or in living
organisms, on their body
materials
Ticks, tapeworms, fleas
Omnivore
Both plants and animals
Bears, people, skunks
Scavenger
Dead or dying animals
Vultures, crows, crayfish
Detritivore
Dead plants and leaves
Beetles, fungus
Decomposer
Small particles and dead
portions of other
organisms
Bacteria, fungus
THE SUN IS THE SOURCE OF
ENERGY FOR ALL LIVING
THINGS (almost)
– photosynthesis in autotrophic organisms
converts sunlight energy into
carbohydrates (BIOMASS)
– they use oxygen to accomplish this
– organisms are called photosynthetic
autotrophs (plants and algae)
• BIOMASS: the total weight of living
matter in an ecosystem
• It accumulates in the food chain as
processed energy
• Energy
can be
“lost”
?
exception to the rule
• CHEMOSYNTHESIS
– organisms make carbohydrates out of
carbon dioxide, water and inorganic
compounds (like sulfur and nitrates)
– organisms are called chemosynthetic
autotrophs (deep ocean bacteria)
Chemosynthetic
organisms
Deep Ocean Ecosystems
FOOD CHAINS
• a series of organisms which pass
energy from one feeding level to the
next
• This process coverts one form of
biomass to another
• these levels are called TROPHIC
LEVELS
TROPHIC LEVELS
• Primary Producer
• Primary Consumer
• Secondary Consumer
• After secondary you can call them
“higher consumers” by referring to
their trophic level (3rd consumer, 4th
consumer…..)
Food Chains
• always contain: sun, primary
producer, decomposer
– primary producer are autotrophs
• the arrow points in the direction the
energy is being transferred to
• always flows in one direction
• reads as “is eaten by”
examples
sun
carrot
rabbit
sun
acorns
squirrel
sun
grass
deer
energy
bacteria
hawk
bear
human
bacteria
bacteria
Primary consumer
Primary producer
Decomposer
some general rules
• Large carnivores do not eat large
carnivores
• herbivores do not eat carnivores
• organisms within an ecosystem may
compete for food sources
• interacting food chains are called
FOOD WEBS
?
WHATS
MISSING?
?
ENERGY PYRAMID or
PYRAMID OF BIOMASS
Energy
lost
10% to next level
90% used/lost at each level
-biomass decreases at each step in a food chain
-energy is lost at each step: bones not used, fur, energy
expended in eating and metabolism, feces….
• larger organisms require more energy
so there will be fewer at the upper
levels
• the shorter the food chain, the more
organisms you can feed at the upper
levels
1 human
300 trout
90, 000 frogs
27, 000,000 grasshoppers
1000 tons of grass
900 human
27, 000,000 grasshoppers
1000 tons of grass
?
?
IV. MATERIALS CYCLE
• MATERIALS CYCLE IN ECOSYSTEMS
– water cycle
– carbon cycle
– nitrogen cycle
All elements will cycle because the earth will
run out of material if it does not!
WATER CYCLE
Water Goes Up
Evaporation- heat causes the conversion of
liquid water into gaseous water (water
vapor)
Transpiration- the evaporation of water
from the surfaces of leaves
-water is produced during photosynthesis
Water changes form
Condensation- due to cooling, gaseous water
forms liquid water on the surface of a
condensation nuclei
Condensation nuclei- a small solid particle of
matter in the atmosphere on which water
will condense
Water comes down
Precipitation-the falling of a condensed
form of water from the atmosphere
-could be solid or liquid
-occurs because the amount of water on
the condensation nuclei becomes heavy
and gravity causes the drop to fall
3 places water goes
1. Runs off into rivers, lakes, streams,
wetlands
2. Percolates into the soil and is absorbed
into plants
3. Percolates into the aquifer
Percolate: to move into an area occupied by
air and fill the molecular space
The Aquifer
•Aquifers are underground layers of porous
rock or sand that allows the movement of
water between layers of non-porous rock
(sandstone, gravel, or fractured limestone
or granite).
• Water infiltrates into the soil through
pores, cracks, and other spaces until it
reaches the zone of saturation where all of
the spaces are filled with water (rather
than air).
• The zone of saturation occurs because
water infiltrating the soil reaches an
impermeable layer of rocks which it can
not penetrate any further into the earth
• Water held in aquifers is know as
GROUNDWATER
• The top of the zone of saturation is
known as the WATER TABLE.
–.
-The water table typically follows the form of
the above ground topography.
-The water table levels can change
Drier =deeper wet areas =at or near surface
• Two main forces drive the movement of
groundwater
– First water moves from higher
elevations to lower elevation due to
the effect of gravity
– Second, water moves from areas of
higher pressure to areas of lower
pressure
– Third, water moves at a rate and
amount related to the size and amount
of spaces in the rock layer
Movement of ground water takes time—how much is
variable, depending on the material it moves through
and how deep you go.
CARBON CYCLE
Carbon Cycles through
A. Food chains and Food Webs as
biomass
B. Decomposers release carbon as both
a gas and an element
C. Respiration of plants and animals
Natural Sources of Carbon include: plants
and animals, soil, fossil fuel deposits,
atmosphere, humus…..
-any form of biomass will be a place of
carbon storage
Man-made Sources of Carbon include:
burning of fossil fuels and other organic
materials
Carbon Sinks
Carbon Sink -long term storage of carbon
3 long term carbon sinks
-deep ocean waters
-deep ocean sediments
-fossil fuel deposits
Short term carbon sinks
-plants and animals
-atmosphere
NITROGEN CYCLE
Nitrogen cycles through
A. Food chains and food webs
B. Decomposition of biomass
C. Water
Natural Sources of nitrogen: biomass,
decomposition, lightning, volcanoes
Man-made Sources of nitrogen: fertilizers,
industry, combustion of fossil fuels
Nitrogen must be “fixed”
Nitrogen is made in nature in an elemental form
N2
-most living things can not use this form
Nitrogen fixation -the process in which nitrogen
fixing organisms convert N2 into useable forms
-Nitrogen fixing Bacteria and Legumes are
symbiotic organisms which fix N2
-fixed forms include Nitrates NO3-, Nitrites
(NO2-) and Ammonia (NH4+)
V. ECOSYSTEMS CHANGE
• SUCCESSION CAUSES CHANGES
IN ECOSYSTEMS
– ecosystems are never static
– ecosystems tend to move from less
diverse to more diverse systems
low species
diversity
high species
diversity
more energy
available
less energy
available
less biomass
more biomass
Primary Succession
• occurs where no
ecosystem has
occurred before
• uses pioneer species
(lichens, moss) to form
soils
• begins on rock
• often accompanies a
cataclysmic event
Pioneer Species
• small plant organisms like
lichens and mosses
• their “roots” will gradually
break off small chips of
rocks
• as they grow and die, the
organic material mixes
with the chips of rocks
• soils begin to form (200
years = 1 inch of top soil)
Secondary Succession
• occurs in areas of disturbance of
existing ecosystems
• species who are opportunistic will
begin process
• opportunistic species are generally
fast growing and have a high
reproductive rate
There are natural
patterns of
succession.
-fields become
forests
-ponds become fields
-forests will change
types of vegetation
until maturity
Maturity
• ecosystems will become more complex
• complexity slows rates of change
• the higher the maturity, the longer
the ecosystem will stay in that state
• in general--fields become shrub lands
-- shrub lands become forests
-- ponds will become grasslands
• as the ecosystem changes, the
species composition changes
Fire Maintained Ecosystems
• tends to halt/slow succession
• maintains a particular successional
state
• some species require fire for
reproduction
• fire is used as a management tool to
maintain ecosystems
Climax Communities
• all ecosystems tend to move toward
an idealistic end state called a climax
community
• arguments occur about its existence
• climax allows for very little change
Concept 6
Invasive
Keystone
Native
Invasive, Endangered, and
Keystone Species
• Invasive: a species that did not evolve in
the habitat, it was released on purpose or
by accident
• Endangered: a species which are so close
to the critical number that it may become
extinct in the near future
• Keystone: a species which is critical to the
survival of an ecosystem-they are tied to
many other species
Invasive Species
Gypsy Moths
introduced into this
country in 1869 have
devastated much of the
eastern oak forests.
Non-native species do
not have limiting
factors to control their
populations. This
causes elimination of
native species.
Rabbits introduced into Australia have devastated the
native grasslands and endangered kangaroos and other
native wildlife.
Endangered
California Condor
The largest bird of
North America was
brought to the brink of
extinction due to:
-over hunting
-habitat destruction
-egg collecting
-DDT (pesticide)
• In 1987, the last wild condors were
removed and placed with the
remaining population in captivitythere were 26
• A captive breeding program is in
effect and as of 2012 there were
405 birds (226 in wild, rest in zoos)
• Scientists question if they had
reached the critical number as all 27
of the first breeding population had
originated from 14 birds
KEYSTONE SPECIESorganisms which are important
in shaping the total ecology of
an ecosystem
Cray fish and Beaver are both keystone species in
Pennsylvania. It is because they form habitats (like
beaver) or are a major food source for many organisms.
Either way they have major influence over their
ecosystems. Loss of these species would result in
ecosystem collapse.
The Endangered Species Act
• The law requires federal agencies, to ensure
that actions they authorize, fund, or carry out
are not likely to jeopardize the continued
existence of any listed species or result in the
destruction or adverse modification of
designated critical habitat of such species.
• The law also prohibits any action that causes a
"taking" of any listed species of endangered
fish or wildlife. Likewise, import, export,
interstate, and foreign commerce of listed
species are all generally prohibited.
Trophic Cascade
https://connect.usu.edu/p24408776/
• Occur when an organism has a key
role in the balance of the ecosystem
-removal causes changes throughout the
entire ecosystem
-can be top down or bottom up
-often found after the removal of a top
level predator
• In Minnesota wolves suppress coyote
populations, which in turn releases
foxes from top-down control by
coyote
• The fox then control the
intermediate prey species (bunnies
and squirrels)
• This allows the competition between
the herbivores to produce dynamic
equilibrium in populations of
herbivores
Remove the top predator
•
•
•
•
Removal of Wolves releases the coyote
Coyote control more fox
Less fox, more bunnies and squirrels
More bunnies and squirrels, greater
competition between herbivores
• Damage to autotrophic levels
• Decline of herbivores and then their
predators
• Complete ecosystem collapse
http://forestry.usu.edu/htm/video/conferences/rtw-2010/billripple/