Biology ch 2
Principles of Ecology
V. Hassell
Everything on Earth- air, land, water, plants and animals= is connected. Understanding
these connections help us keep our environment clean, healthy and safe..
You willDescribe ecology and the work of ecologistIdentify important aspects of an organism’s environmentTrace the flow of energy and nutrients in the living and nonliving worlds
Principles of Ecology
Why is an understanding of the environment important?
They materials needed for survival come from the environment
It is where they find food and shelter, reproduce and interact with other organisms.
Organisms and their environmentObjectives
Distinguish between biotic and abiotic factors Compare the different levels of biological
organization and living relationships important in ecology.
Explain the difference between a niche and a habitat
Individual organisms interact with each other and their environment
As cities expand, humans are moving into territories previously occupied by fields and wildlife.
They are still in their native area when they turn over trashcans or get into yards.
Natural History
The study of plants and animals, including where they grow and live, what they eat or what eats them
Includes Bird Watchers
Amateur weather collector
EcologyUses qualitative (descriptive) and quantitative research
The study of interactions that take place between organisms and their environment
Uses techniques from
Math Chemistry,
physics, geology Other branches
of biology
Levels of organization help scientist understand relationships.
POPULATION
A group of organisms of the same species which can interbreed and live in the same area at the same time
Because members of the
same population compete
with each other for food,
water, mates, and other
resources. Competition increases when
resources are in short supply
Communities- a group of
interacting populations of different species occupying a particular place a pond
community
Interactions within communities
Made up of individuals of several different populations
Located in a certain area at a certain time A change in one population changes/affects
others. Ex. If a fox population increases, what
happens to the rabbit population?
The organisms in a plant population and the biotic and abiotic factors which impact on them.
Ecosystem
BiosphereThe area on earth which supports life (where life is found)
Thin layer.Supports a diverse group of
organisms in a wide range of climates
Living things are affected by nonliving and living factors.
Ecosystem- Factors
1. biotic living or derived
from living things
2. abiotic- nonliving factors; sunlight
, temp. water, soil
If you were to study a species you would need to include:
their food sources
Materials for habitat
Temperature
Drought Type of soilAmount of
seeds
Growth
Limits of Tolerance conditions under which growth will occur
Optimum Range- the best conditions for growth Limiting factors- A nutrient in short supply
which limits an organisms growth. It keeps populations from spreading beyond areas to which they are best adapted
Biotic factorsLife factors
All living organisms- regardless of size
Are biotic
All organisms depend on others directly or indirectly for food, shelter, reproduction or protection.
Levels of organizationBiologist study
Individual organisms Interactions among organisms of the same
species Interactions among organisms of different
species Effects of abiotic factors on interacting
species
Life Cycles
Organisms may go through metamorphosis which means that the young and adult organisms do not compete for food- eat different foods.
Biotic and Abiotic factorsForm Ecosystems
Because ecosystems include interacting populations and the abiotic factors, they are subject to change
Biomes2 types of Ecosystems
Terrestrial ecosystems- on land Include forest, measows and rotting logs Aquatic ecosystems include fresh water and
saltwater forms Fresh water- Includes ponds, lakes, streams Salt water – called Marine ecosystems, make
up 70% of earth’s surface
Adaptation & change
Organisms must be able to adapt to changing conditions.
Coastal organisms spend part of the day underwater.
Tides affect salinity (salt content)
Organisms in EcosystemsHABITAT
Where an organism lives its life
Prairie dog- burrows in prairie
Birds- nest in trees or on the ground
Others- Wetlands, ponds, oceans
Food Chain- Sun is energy source1st Producer-
AutotrophPhotosynthesi
splant
A niche
includes how it meets its specific needs for food, helter, how and where it survives and where it reproduces
Includes all interactions with biotic and abiotic parts of habitat
Nichecompetition
It is an advantage to have a different nich than other species in the habitat
Less competition
2 species with the same needs can’t exist for long together
One will gain control Other become
extinct, move elsewhere or adapt
Surviving in difficult habitats
Adaptations to survive in different habitats include
Cypress kneesPolar bears
SymbiosisOrganisms living together in close, permanent associationTypesMutualism- both species benefitCommensalism- one species
benefits, the other is not affectedParasitism- one benefits, one is
harmed
Symbiosis- Commensalism
Spanish mossOrchidsbarnacles
Symbiosis- ParasitismHarmful to one species, beneficial to another
EndoparasiteHook wormsDo they care if
their host dies?
Exoparasite- outside
Tick, fleas
2.2 objectives
Compare how organisms satisfy their nutritional needs.
Trace the path of energy and matter in an ecosystem
Analyze how matter is cycled in the abiotic and biotic parts of the biosphere
How organisms obtain EnergyAutotrophs
The ultimate source of energy is the sun
Plants use photosynthesis to produce food from light energy.
Autotrophs Producers
Plants Some protist &
algae
Other organisms depend on thes for energy
How organisms obtain energyConsumers are Heterotrophs
Can not make its own food
Obtain nutrients by eating other organisms
Heterotrophs Omnivore Carnivore Scavenger
Heterotrops- DecomposerBreakdown and release materials
Breakdown complex compounds of dead and decaying organisms into simpler substances
Fungi, bacteria
Flow of energy in Ecosystems Cycles of matter
Matter is composed of carbon, nitrogen and other elements
Moves through the food chain from producers to consumers
Food ChainsFlow of energy
Arrows indicaate direction in which energy is transferred
May be as few as one or two – or unlimited
Plants decomposersPlantscowmandecomposer
(bacteria)
Food web
Shows relationships for organisms that feed on more than one species
Ecological PyramidsOnly 10 % of energy is passed to next level
Flow of Energy
Food chains, food webs and ecological pyramids are all models that show how energy moves in only one direction through the tropich levles of an ecosystem
Some energy lost to heat Sunlight is souce
According to the law of conservation of energy-
energy is neither lost or gained. Some is transferred at each tropic level enerters the environment as heat, but the total amount of energy remains the same.
Pyramid of Biomasss
Each level in a pyramid of biomass represents the amount tht the level above needs to consume to meet it’s needs
Cycles in NatureMatter is recycled (never lost) and is not replenished like energy from sunlgiht
There is a finite amount of matter
The atoms that make up the boies of organisms alive today are the same atoms that have been on Earth since the beginning of time.
Water CycleEvaporation, condensation, transpiration, precipitation
The Carbon CycleLife on earth is a carbon based. Carbon is
molecule of life
Carbon dioxide + water glucose + oxygen
Nitrogen Cycle78 % of atm- not available
to plantsAmmonia (urine), lightning, manure,
excess Nitrogen in waterways
can cause major algae blooms and harm an ecosystem
causes blue baby syndrome
Phosphorus cycle
Phosphorus is essential
All organisms need phosphorusIt is Necessary for growth and development
Short cyclePlants absorb
from soilEaten, animsl
dies , decompose and is returned to soil
Long cycle Phosphates wash
into water and are locked in rock
Millions of years later- rock is exposed
Nitrogen Cycle
Everglades
Lake Okeechobee over flowed producing marshy area
Development limited water to lake
90 % wading birds 70% other wildlife
listed as threatened or endangered
