Ecology
Chapters 2, 3, 4 & 5
Ecology….is the study of the interactions of
living things with each other and with their environment
BIOTIC FACTORS/COMPONENTS – living or once living things
ABIOTIC FACTORS/COMPONENETS – the physical, nonliving environment
In this scene,… What is biotic? What is abiotic?
Biotic or Abiotic?
• Feathers• Rocks• Soil• Water • Grasses• Fungi• Bones• Temperature
Habitat and Niche
habitat – address of organism; where an organism lives
niche – job of an organism; role(s) it plays in its environment
Indigo Bunting
Scarlet Tanager
Eastern Bluebird
What is the niche and habitat
of each bird?
Is it the same for each?
In a field ecosystem what are some….
biotic factors? abiotic factors?
niches? habitats?
Levels of Organization - Hierarchy of Life
• Organism: (simplest level): a single living things SPECIES - structurally similar organisms that naturally
interbreed and produce fertile offspring• Population: all the members of a single species in a given area• Community: all the different living things in a given area• Ecosystem: composed of all the biotic and abiotic factors
in an area• Biome: ecosystems having a characteristic climate and
characteristic organisms• Biosphere (broadest/largest level): includes all areas of the Earth
where life exists
BIOSPHERE
All areas of the Earth
where life exists
Community Interactions(interactions between the species living in an area)
• Competition• Predation• Symbiotic Relationships (symbioses)
– Mutualism– Commensalism– Parasitism
COMPETITION• Results from niche overlap
• Organisms compete for food, water, mates and habitat
• Competitive Exclusion may occur: where one species is eliminated
What would these zebra compete for?
PREDATIONResults when…..• 1 individual kills another (predator)• 1 individual is killed (prey)• One way that natural selection occurs
Examples… hawk snake
lion gazelle fox rabbit
Anti-Predator AdaptationsAlmost all organisms are vulnerable to predation , therefore,
developing adaptations that serve as defenses are an advantage…
Defenses against predators include…– Camouflage– Mimicry– Warning Coloration– Protective Coverings – Secondary Compounds
CAMOUFLAGE coloration or patterns that help an animal to appear to blend in
with its surroundings
MIMICRYa defense in which a harmless species resembles a
venomous or distasteful species
Warning Coloration a bold, distinctive pattern of color characteristic of a poisonous or unpalatable organism – it
serves to warn off potential predators
Protective Coverings a covering that is intended to protect from damage or injury
Secondary Compounds
substances (chemicals) produced by plants as a byproduct of metabolism; usually poisonous, irritating, or distasteful
Example: poison ivy
Types of Symbioses…Mutualism….symbiotic relationship where both
organisms benefit
Commensalism….symbiotic relationship where one individual benefits and the other is unaffected
Parasitism….symbiotic relationship where one individual is harmed (HOST) and the other individual benefits (PARASITE)
PARASITISM
ECTOPARASITES - live outside the host – ticks, fleas, lice
ENDOPARASITES – live inside the host – bacteria, protists, worms
• Hosts have evolved defenses against parasites: skin, tears, saliva, mucus, ….
• Parasites have evolved ways to compensate: tegument, anticoagulants, anesthetics, ….
What type of symbiosis?
Examine the following slides….is it?
Mutualism Commensalism Parasitism
Acacia Plant and Ants
• Ants protect acacia from grazing herbivores
• Acacia provides ants with a place to live and nectar at the base of leaf stalks
Moray Eel with Cleaner Shrimp
• Moray Eel gets…. a clean mouth
• Cleaner Fish gets…. a meal
Flower and Bumble Bee
• Flower gets pollinated by the bee
• Bee gets nectar and pollen from the flower
Silverfish and Army Ants
some species of silverfish inhabit the nests of army ants and live by scavenging on the refuse of their hosts, but without affecting the ants
Cape Buffalo with Egrets
• Cattle stir up insects as they eat grass and move around
• Egrets hang around and eat insects from cattle and surroundings
Tapeworm and Human• Worm infects the human body…..
Lichen : Fungus and Alga• Fungi support and
protect the algae, allowing it to live in areas usually unsuitable to the algae
• Algae provide food through the process of photosynthesis
Birds Nesting in a Tree
Vampire Finch and Other BirdsThe vampire finch supplements it s diet by feeding on the blood of other birds by pecking at the skin until they draw blood
Clown Fish with Anemone
Clown fish gets protection from it predators
Sea Anemone gets ?
What symbioses is this?
Heart Worms
What symbioses is this?
Embedded Tunga fleas
What symbioses is this?
What symbioses is this?
What symbioses is this?
How Living Things Meet Their Energy Needs
The energy source for most living things is….
AUTOTROPHS (producers) – can
produce their own food and meet their own energy needs auto = “self” troph = “feeder”
Autotrophs can be …. photoautotrophs or chemoautotrophs
Photoautotrophs (plants, algae, some bacteria) perform….Photosynthesis – which uses light energy to produce carbohydrates /food/fuel
Chemoautotrophs (some bacteria) perform….Chemosynthesis – uses chemical energy to
produce carbohydrates/food/fuel
Plant Responses (Tropisms)• Phototropism =
response toward light
• Geo/Gravitropism = response toward gravity
• Thigmotropism = response to pressure or touch
HETEROTROPHS (consumers) – cannot produce their food and must consume other living things hetero = “other” troph = “feeder”
There are many different kinds of heterotrophs including….
Herbivores – feed on plants Carnivores – feed on animals Omnivores – feed on plants and animals Detritivores – feed on detritus (dead organic matter)
includes…worms, beetles Decomposers – break down organic matter and
recycle nutrients - includes…bacteria and fungi
Energy Flow through an Ecosystem
THE SUN producers consumers
energy flows in ONE DIRECTION in an ecosystem – from producers to consumers
Food Chain
a series of steps in which organisms transfer energy by eating and being eaten
Food Web
the interrelated food chains within an ecosystem
TROPHIC LEVEL(“feeding” level)
each step in a food chain or food web is called a trophic level
a trophic level indicates an organism’s position in the sequence of energy transfers
most ecosystems have only 3 or 4 trophic levels
Is this a food chain or a food web?
How many trophic levels
are in the diagram?
• producers – • primary (1st order) consumers – • secondary (2nd order) consumers – • tertiary (3rd order) consumers – • quaternary (4th order) consumers –
Trophic levels can be represented with an ECOLOGICAL PYRAMID which shows the relative amounts of MATTER AND ENERGY contained within each level
Ecological Pyramids
used to represent the relative amounts of energy or matter contained within each trophic level
ENERGY PYRAMID BIOMASS PYRAMID PYRAMID OF NUMBERS
Energy Pyramid
• shows the relative amount of energy available at each trophic level
• only about 10 % of the energy available at each level is transferred to the next
• about 90% of the energy at each level is lost as heat or is used in life processes ….
–such as digestion, running, eating, respiration, maintaining temperature, sleeping,….
Biomass Pyramid
represents the amount of biomass (living organic matter) at each trophic level
represents the amount of potential food available for each trophic level
typically, the greatest biomass is at the bottom of the pyramid
Pyramid of Numbers
represents the relative number of individual organisms at each trophic level
Biogeochemical Cycle(bio=life, geo=earth, chemical cycle)
elements, chemical compounds and other forms of matter MUST BE RECYCLED and are passed from one organism to another and from one part of the biosphere to another through a biogeochemical cycles
The Water Cycle(also called the hydrologic cycle)
Is the movement of water between the ocean, the atmosphere and the land
Evaporation – water changes from liquid to gasTranspiration – water loss (evaporation) from plants Perspiration – water loss (evaporation) from animals
Condensation – formation of liquid water from water vapor Precipitation – water returns to Earth’s surface as
rain, snow, sleet or hail
IMPORTANCE OF WATER…
Carbon(& Oxygen) Cyclethe cycling of carbon and oxygen between the various
components of the biosphere – organisms, air, water, land,…
Important processes in this cycle….• Decomposition - • Combustion - • Respiration -
Importance of carbon and oxygen - key ingredient in all living things C, H, O, N
Nitrogen Cycle
the cycling of nitrogen between the atmosphere, living things and large bodies of water
Nitrogen Fixation – conversion of nitrogen gas into ammonia – performed by some bacteria
Denitrification – conversion of nitrates into nitrogen gas – performed by some bacteria
all organisms require N to make amino acids which in turn are used to make proteins (in protein synthesis)
Phosphorus Cycle
the cycling of phosphorus between living organisms, rocks, soil and ocean sediments
unlike water, carbon, oxygen and nitrogen - phosphorus does not usually enter the atmosphere
phosphorus is essential to living things because it is an important component of DNA and RNA
Communities
Limiting Factor - biotic or abiotic factor that restricts the numbers, reproduction, or distribution of an organism
Examples of limiting factors…food, water, habitat, disease, fire and other natural disasters,….
Ecological Successionthe changes in a community that occur over time
• occurs when a new land area is exposed or when an existing land area is disturbed
Succession usually culminates in a climax community.
Climax Community….• the end result of succession• the final (stable) community to inhabit an area
The climax community of Baja, California
is a desert.
Primary Successionoccurs on new land areas or where no soil exists –
EXAMPLES - volcanic islands, bare rock, glacier melting,…
Pioneer Species – the first species to inhabit an area – usually mosses and lichens What is a lichen?
Secondary Succession occurs when an existing community had been disturbed and
regrowth occurs
Latitude effects climate• Latitude = the distance of any point on Earth
from the equator.• Climate is directly affected by receiving
unequal solar radiation
CLIMATEthe average year to yearconditions of temperature
and precipitation in a particular region
What is our climate?
What is Alaska’s climate?
WEATHER
the day to day conditions of the Earth’s atmosphere at a particular time and place
What was the weather on Thanksgiving Day?
Greenhouse EffectA natural phenomenon that occurs when heat is
retained (TRAPPED) by the atmosphere
Helps to keep the planet warm and life on Earth possible
Carbon dioxide, methane, water vapor and other gases in the atmosphere trap heat
The atmosphere acts like an insulating blanket around the planet
Some scientists believe that an …..
ENHANCED GREENHOUSE EFFECT = GLOBAL WARMING
In summary…
Latitude determines climateClimate determines weather Weather determines precipitation
Precipitation determines flora (plant life)
Flora determines fauna (animal life)
Do you see the relationship?
BIOMElarge geographical area having…
characteristic temperature range and precipitationcharacteristic plants and animals
TERRESTRIAL (land) BIOMES TUNDRA TAIGA or BOREAL FOREST or CONIFEROUS FOREST TEMPERATE DECIDUOUS FOREST TEMPERATE RAIN FOREST TEMPERATE GRASSLAND TROPICAL GRASSLAND OR TROPICAL SAVANNA DESERT – hot or cold TROPICAL RAIN FOREST
Tundra
• Cold & treeless• Covers 1/5 of world’s land• Little precipitation (mostly frozen)• Flora: Small, slow growing plants (grass, moss, sedge)• Fauna: caribou, arctic fox, snowy owl, musk oxen• Permafrost: permanently frozen layer of soil under
surface• Summer can cause boggy ponds & different fauna
Tundra
Taiga (or Boreal Forest or Coniferous Forest)• south of the tundra; in the N hemisphere• Flora: cone-bearing, evergreen trees - CONIFERS
(pines, hemlocks, spruces, junipers, firs)• Fauna: moose, grizzly bear, wolf
Taiga (or Boreal Forest or Coniferous Forest)
Temperate Deciduous Forest
Temperate Deciduous Forest
• Trees that lose their leaves are found here = deciduous trees
• Warmer winter, longer summers = temperate• Flora: birch, oak, maple, beech, dogwood, &
some evergreens• Fauna: fox, squirrel, WT deer, raccoon, black
bear, coyote
*you live in this biome
Temperate Deciduous Forest
Temperate Grassland
• Also known as prairies (“the bread basket”)• Dominated by grasses• Less rainfall, so not too many tall trees• Rich, fertile soil• Flora: corn, wheat, potatoes, many other cereal grains• Fauna: coyote, gopher, grazing animals (bison, antelope,…)
Tropical Grassland
or Tropical Savanna
Tropical Grassland or Tropical Savanna• can be in tropical or subtropical regions• Flora: Mainly grasslands with scattered trees & shrubs• Fauna: lots of herbivores (zebra, giraffe, gazelle) as well
as carnivores (lions, leopards, cheetahs)
Desert HOT AND COLD
• Less than 10 inches (25 cm) rainfall per year• Can be cold because of the low humidity (moisture)• Sparse vegetation that have adaptations for the dry
conditions– waxy coating, water storage, transpire @ night, thorns on
exterior for protection• Flora: cacti, Joshua trees, creosote,…• Fauna: kit foxes, snakes, lizards, road runners,…
Animals
Tropical Rainforestmost productive biome –
GREATEST BIODIVERSITY
BIODIVERSITY = the variety of living things in an area
3 kinds of biodiversity species, ecosystem, genetic
• most of world’s species live here • warm year round• little variation in temperature
Tropical Rainforest• Canopy - formed from a
continuous layer of treetops that shades the forest floor
• Precipitation: 100 + inches per year; rains almost daily
• Flora: lilies, orchids, vines, broad-leaved trees, ferns,…
• Fauna: sloth, birds, monkeys, beetles, butterflies…
scarlet macaw marmoset
Aquatic/Water Ecosystems are determined by water chemistry (pH, salinity, dissolved
oxygen,…) depth, flow and temperature
Aquatic EcosystemsSALTWATER - includes marine areas and salt lakes - these areas contain a higher percentage of dissolved salt
Marine areas include…oceans, coral reefs, bays, gulfs, seas• these areas make up 97.5% of water on Earth
Aquatic EcosystemsFRESHWATER AQUATIC ECOSYSTEMS - contain little dissolved salt - Include rivers, streams, lakes, ponds,… - make up only 2.5% of water on Earth - most freshwater is “tied up” in glaciers and polar ice caps
GROUNDWATER… water found under ground
There are transitional aquatic ecosystems where saltwater and freshwater merge….
wetlands and estuaries
Estuary - wetlands formed where rivers
(fresh water) meet salt water
• these areas are affected by the rise and fall of tides
• are usually shallow • serve as spawning
and nurseries for many aquatic species
Population Density The number of individuals in a given area
Factors that may affect population density….
Density independent factor – affects a population regardless of the density of the population – usually abiotic; weather events…
examplesDensity dependent factor – affects a population
on the basis of the number of organisms – predation, competition, parasitism, disease,…
More population density factors…
• Immigration – movement of individuals into an area
• Emigration – movement of individuals out of an area
Carrying Capacity – the number of individuals that can be supported by a given area (even a grocery bag has a carrying capacity)
Human population growth is causing…
• severe overcrowding in areas• An increase in energy demands• A need for increased food supply and waste disposal• very rapid ecological change (habitat destruction,
overhunting, introduction of diseases)
* The population tripled from 1930-2000 and is expected to double again from 2000-2050