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..

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

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

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

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

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

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