Transcript ECOLOGY AND ECOSYSTEMS

ECOLOGY AND
ECOSYSTEMS
ECOLOGY
IS THE STUDY OF THE
INTERACTIONS BETWEEN
ORGANISMS AND THEIR
ENVIRONMENTS
ECOSYSTEM
• A LIMITED AREA IN WHICH LIVING
AND NONLIVING THINGS
INTERACT
• IT IS SHAPED BY:
1. ABIOTIC FACTORS - THE
NONLIVING FACTORS /
PHYSICAL ENVIRONMENT
2. BIOTIC FACTORS- LIVING
ORGANISMS
ACTIVITY #1
PLACE THE
EAGLES IN THE
PROPER
CATEGORIES,
DEPENDING ON
WHETHER THEY
ARE DESCRIBING
AN ABIOTIC
FACTOR OR A
BIOTIC FACTOR.
Ecosystem Dynamics
TWO KEY PROCESSES:
1. ENERGY FLOW
2. CHEMICAL CYCLING
ENERGY FLOW
Two types of energy sources:
1. Light Energy- the main energy
source for life on Earth; used by
autotrophs to carry out
photosynthesis.
2. Inorganic Chemical Compoundsare used by autotrophs that can
produce food in the absence of
light. The process is called
“chemosynthesis.”
• PRODUCERS – autotrophs
MANUFACTURE THEIR
OWN FOOD – via
PHOTOSYNTHESIS or
CHEMOSYNTHESIS.
• CONSUMERS – heterotrophs
rely on other organisms for
their energy and food supply.
TYPES OF CONSUMERS - Heterotrophs
• HERBIVORES- eat only plants
• CARNIVORES – eat animals
• OMNIVORES – eat both plants and
animals
• DETRITIVORES – feed on animal
remains or other dead matter ( crabs,
earthworms, ants)
• DECOMPOSERS- break down
organic matter ( bacteria, fungi)
What’s for dinner?
• FOOD CHAINS- a series of steps in
which organisms transfer energy by eating
and being eaten.
• FOOD WEBS- link all the food chains in
the ecosystem together.
• TROPHIC LEVEL- each step in a food
chain. Producers – first level, consumerssecond, third or higher.
Ecological Pyramids
Ecological pyramid is a diagram that
shows the amounts of energy or matter
contained within each trophic level.
3 Types:
ENERGY PYRAMID
BIOMASS PYRAMID
PYRAMID of NUMBERS
Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this
energy for life processes.
The rest is lost as heat.
Pyramid of Numbers
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.
Shows the relative number of
Individual organisms at each
trophic level.
How much energy is available to first-, second-, and third-level
consumers, if there are 50,000 kcal available at the producers’ trophic
level?
A
B
C
D
250, 25, and 1
3000, 250, and 25
5000, 500, and 50
1, 25, and 250
In the food chain, what percentage of the energy stored in the krill
probably would be transferred to the cod?
A. More than 90 percent
B. About 75 percent
C. About 50 percent
D. Less than 15 percent
BIOMASS
PYRAMID:
PYRAMID OF
NUMBERS:
3rd Level Consumers
2nd Level Consumers
1st Level Consumers
Producers
What is true about the pyramid of numbers?
i 1st level consumers compose the greatest number of individuals.
ii There are more 3rd level consumers than 2nd level consumers.
iii There are more producers than 1st level consumers.
A. i only
B. ii only
C. i and ii only
D. ii and iii only
E. i, ii, and iii
BIOMASS
PYRAMID:
PYRAMID OF
NUMBERS:
3rd Level Consumers
2nd Level Consumers
1st Level Consumers
Producers
What can you conclude based on the two pyramids?
i The producers are probably small, like single-celled algae in a body of
water.
ii The producers are probably large, like trees in a forest.
iii No reasonable conclusion can be drawn from the information given.
A. i only
B. ii only
C. i and ii only
D. ii and iii only
E. i, ii, and iii
CYCLES OF MATTER
Only 4 elements –
oxygen
carbon
hydrogen
nitrogen
-make up over 95% of
the body in most
organisms.
Cycles of Matter
Unlike the one-way flow of energy, matter
is recycled within and between
ecosystems.
The process of chemical recycling in an
ecosystem, involving both biotic and
abiotic factors- is called Biogeochemical
Cycle;
BioGeoChemical Cycle
Consumers
Producers
Detritivores
Nutrients avail.
to producers
Abiotic reservoir
Geologic Processes
The Water Cycle
Condensation
Precipitation
Evaporation
Transpiration
Runoff
Seepage
Root
Uptake
The Water Cycle
There are 3 major processes driven by solar
energy: Precipitation, Evaporation, and
Transpiration - that continuously move water
between the land, oceans, and atmosphere.
Over the oceans, evaporation > precipitation;
Water vapor in clouds gets carried by winds
across the land.
On land, precipitation > evaporation and
transpiration. The excess precipitation forms
lakes, rivers, and groundwater- that flow back to
the sea, completing the water cycle.
The Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean
The Carbon Cycle
Carbon- major ingredient of all organic molecules.
Its abiotic reservoir is atmosphere, oceans,
rocks, soil; biotic- organisms.
Photosynthesis, respiration, and decomposition
take up and release carbon and oxygen.
Erosion and volcanic activity release carbon
dioxide
Decomposition- leads to fossil fuels, carbon
underground.
Human activities- mining, burning fuels, etc.
release carbon dioxide.
The Nitrogen Cycle
N2 in Atmosphere
NH3
NO3and NO2-
The Nitrogen Cycle
The main reservoir- atmosphere. Ingredient of
amino acids; Cycles through the soil and
organisms.
Although atmosphere contains 79% nitrogen gas,
only certain types of bacteria can use this form
directly. The bacteria lives in the soil, plant roots
and binds nitrogen to hydrogen to form ammonia
(process called “nitrogen fixation”); Other bacteria
performs “nitrification”- convert ammonia into
nitrates and nitrites.
Denitrification- nitrates converted into nitrogen gas.
Phosphorus Cycle
Part of DNA and RNA; does not enter
atmosphere.
Main abiotic reservoir- rock, which upon
weathering releases phosphorus.
Some phosphate cycles between organisms
and the soil on land.
Levels of Organization
Levels of Organization
BIOSPHERE- part of Earth in which life
exists including land ( lithosphere), water
(hydrosphere), and air ( atmosphere.)
8km ~ 5miles
Earth’s Surface
11km ~ 6.8miles
Levels of Organization
BIOME- a group of ecosystems that have
the same climate and dominant
communities ( plants & animals.)
Examples: Tropical Rain Forest
Desert
Temperate Grassland
Tundra
10 MAJOR BIOMES
Ten Major Biomes
Biome
Tropical Rain
Forest
Tropical Dry
Forest
Tropical
Savanna
Desert
Temperate
Grassland
Temperate
woodland and
Shrubland
Temperate
Forest
Northwestern
Coniferous
Forest
Boreal Forest
Tundra
Precipitation Temperature
high
hot
Soil
poor
Diversity
high
Trees
dense
Grasses
sparse
variable
mild
rich
moderate
medium
medium
variable
mild
clay
moderate
sparse
dense
low
moderate
variable
summer hot
poor
rich
moderate
moderate
sparse
absent
sparse
dense
summer low, summer hot
winter
moderate
moderate
summer
moderate,
winter cold
high
summer mild,
winter cold
poor
low
medium
medium
rich
high
dense
sparse
rocky,
acidic
low
dense
sparse
moderate
poor, acidic moderate
dense
sparse
poor
absent
medium
low
summer mild,
winter cool
summer mild,
winter cold
low
The Role of Climate
Sunlight
Sunlight
Most direct sunlight
Sunlight
Sunlight
Levels of Organization
ECOSYSTEM- all organisms in a particular
area, along with the abiotic factors with
which they interact.
Examples: Lakes, Forests, Marshes, etc.
Two general categories of ecosystems:
- Terrestrial
- Aquatic
Levels of Organization
COMMUNITY – all of the organisms living
in a specific place.
Levels of Organization
POPULATION – groups of individuals that
belong to the same species and live in the
same area/ecosystem.
Can a group of rabbits and a group of mice make
up the same population in an ecosystem?
Levels of Organization
INDIVIDUAL SPECIES – a group of
organisms that are similar to one
another and can breed and produce
fertile offspring;
Organism- the smallest living unit of the
biosphere.
BIODIVERSITY- the number and variety of
species living within an ecosystem.
CARRYING CAPACITY– the ability of the
ecosystem to support the organisms in its
ecosystem.
Community Interactions
When organisms live together, they interact.
Interactions such as COMPETITION,
PREDATION, and SYMBIOSIS help shape
the ecosystem in which they live.
• Competition- organisms compete for the same
limited resource ( water, nutrients, light, food, or
space.)
“ Competitive exclusion principle”- no two species can occupy the
same niche in the same habitat at the same time.
Predation- one organism captures and feeds on
another.
• Symbiosis- “living together”:
Mutualism – both organisms benefit
Commensalism- one organism benefits and the
other is neither harmed nor helped
Parasitism- one organism, the parasite,
benefits; and the other, the host, is harmed
Test your knowledge:
1. The anemone is found attached to the shell in which the
hermit crab lives. When crab searches for food, the
anemone is brought into contact with a greater supply of
food. The crab doesn’t mind his host; anemone's stinging
cells protects him too.
2. Tapeworms have no gut, so they rely on their host to
provide them with already digested food. The host later
suffers harm.
3. Oxpeckers run over the backs of hippopotami. These
birds rid their partners of injurious and annoying pests
and in doing so obtain a ready supply of food.
4. Spiders build their webs on trees.
5. Phoretic mite attaches the fly for transportation only.