Chapter 3 EcologyChapter 3 Ecology

Ecology – the scientific study of Ecology – the scientific study of interactions among organisms and interactions among organisms and between organisms and their between organisms and their environment.environment.

The term ecology was coined in 1866 by The term ecology was coined in 1866 by Ernst Haeckel Ernst Haeckel

oikos is greek for houseoikos is greek for house

Biosphere – combined portions of the Biosphere – combined portions of the planet in which all life existsplanet in which all life exists

The biosphere is from 8 km above the The biosphere is from 8 km above the surface to 11 km below sea level.surface to 11 km below sea level.

Levels of OrganizationLevels of Organization

Species – a group of organisms so Species – a group of organisms so similar to each other that they can breed similar to each other that they can breed and produce fertile offspring.and produce fertile offspring.

Populations – groups of individuals that Populations – groups of individuals that belong to the same species and live in belong to the same species and live in the same area. the same area.

Species of Sea TurtlesSpecies of Sea Turtles

Green

Hawksbill

Kemp RidleyLeatherback

Loggerhead

Olive RidleyWebsite

Flatback

Levels of OrganizationLevels of Organization

Community – a group of different species Community – a group of different species that live in the same area.that live in the same area.

Ecosystem – a collection of all of the Ecosystem – a collection of all of the organisms that live in a particular place organisms that live in a particular place together with the nonliving aspects of the together with the nonliving aspects of the environment.environment.

Pelagic Waters Pelagic Waters (community)(community)

The open oceanThe open ocean The pre-juveniles feed on zooplanktonThe pre-juveniles feed on zooplankton

And Nekton And Nekton

Copepod Jellyfish Krill

Oysters (intertidal zones and bays

ScallopsSubtidal Zonesbays

BiomeBiome

A biome is a group of ecosystems that A biome is a group of ecosystems that have the same climate and dominant have the same climate and dominant communities.communities.

The biosphere is the highest level of The biosphere is the highest level of organization.organization.

Ecological MethodsEcological Methods

Binoculars, magnifying glasses, Binoculars, magnifying glasses, microscopes, DNA, field camerasmicroscopes, DNA, field cameras

Modern research uses three approaches;Modern research uses three approaches; observing, experimenting, and modelingobserving, experimenting, and modeling

Observing – first stepObserving – first step

Experimenting – to test a Experimenting – to test a hypothesis….field or labhypothesis….field or lab

Modeling – used to gain insight into Modeling – used to gain insight into complex phenomena (weather)complex phenomena (weather)

Energy FlowEnergy Flow The flow of energy through an The flow of energy through an

ecosystem is one of the most important ecosystem is one of the most important factors that determines the system’s factors that determines the system’s capacity to sustain life.capacity to sustain life.

Sunlight is the main energy source for Sunlight is the main energy source for life on Earth. Less than 3% of the life on Earth. Less than 3% of the energy from the sun that strikes the energy from the sun that strikes the Earth is used.Earth is used.

Some types of organisms rely on the Some types of organisms rely on the energy stored in inorganic chemical energy stored in inorganic chemical compounds. compounds.

hot springs and undersea ventshot springs and undersea vents

Only plants, some algae, and certain Only plants, some algae, and certain bacteria can capture energy from sunlight bacteria can capture energy from sunlight or chemicals and use that energy to or chemicals and use that energy to produce food.produce food.

Autotrophs – assemble organic Autotrophs – assemble organic molecules from inorganic moleculesmolecules from inorganic molecules

Autotrophs are also called producers Autotrophs are also called producers because they make their own food.because they make their own food.

The best known autotrophs are those The best known autotrophs are those that harness solar energy through that harness solar energy through photosynthesis.photosynthesis.

During photosynthesis, light energy is During photosynthesis, light energy is used to power chemical reactions that used to power chemical reactions that convert carbon dioxide and water into convert carbon dioxide and water into oxygen and carbohydrates.oxygen and carbohydrates.

carbohydrates are sugars or starches carbohydrates are sugars or starches

This process provides us with oxygen This process provides us with oxygen and removes carbon dioxide in the and removes carbon dioxide in the atmosphere.atmosphere.

6CO6CO22 + 6H + 6H22O O C C66HH1212OO66 + 6O + 6O22

Plants - landPlants - land Algae - mostly oceansAlgae - mostly oceans Bacteria - tidal flats and salt marshes Bacteria - tidal flats and salt marshes

(cyanobacteria are the most common)(cyanobacteria are the most common)

Cyanobacteria

ChemosynthesisChemosynthesis

when organisms use chemical energy to when organisms use chemical energy to produce carbohydrates.produce carbohydrates.

they produce food in the absence of lightthey produce food in the absence of light they rely on energy in the chemical they rely on energy in the chemical

bonds of inorganic molecules like bonds of inorganic molecules like hydrogen sulfide (Hhydrogen sulfide (H22S)S)

mostly bacteria mostly bacteria found in hot springs like yellowstone and found in hot springs like yellowstone and

hydrothermal ocean ventshydrothermal ocean vents

HeterotrophsHeterotrophs

Organisms that rely on other organisms Organisms that rely on other organisms for their energy and food supply.for their energy and food supply.

Also called consumersAlso called consumers

Types of HeterotrophsTypes of Heterotrophs

herbivores – obtain energy from plantsherbivores – obtain energy from plants carnivores – eat animalscarnivores – eat animals omnivores – eat plants and animalsomnivores – eat plants and animals detritivores – feed on plant and animal detritivores – feed on plant and animal

remains ….or dead matterremains ….or dead matter decomposers – break down organic decomposers – break down organic

mattermatter

Feeding RelationshipsFeeding Relationships

Energy flows in an ecosystem in one Energy flows in an ecosystem in one direction, from the sun or inorganic direction, from the sun or inorganic compounds to autotrophs and then to compounds to autotrophs and then to various heterotrophs.various heterotrophs.

Food ChainsFood Chains

The energy stored by producers is The energy stored by producers is passed from organism to organism in a passed from organism to organism in a series of steps called a food chain.series of steps called a food chain.

Grass - Antelope - CoyoteGrass - Antelope - Coyote

Algae - Zooplankton - Small fish - Squid - SharkAlgae - Zooplankton - Small fish - Squid - Shark

Food Webs Food Webs

When the feeding relationships in an When the feeding relationships in an ecosystem form a network of complex ecosystem form a network of complex interactions it is called a food web. interactions it is called a food web.

Each step in a food chain or web is called Each step in a food chain or web is called a trophic level. a trophic level.

Ecological PyramidsEcological Pyramids

A diagram that shows the relative amounts of A diagram that shows the relative amounts of energy or matter contained within each trophic energy or matter contained within each trophic level of a food chain or web. level of a food chain or web.

There are three different types of ecological There are three different types of ecological pyramids;pyramids; Energy Pyramids, Biomass Pyramids, and Energy Pyramids, Biomass Pyramids, and

Pyramids of NumbersPyramids of Numbers

Energy PyramidsEnergy Pyramids

There is no limit to the number of trophic There is no limit to the number of trophic levels that a food chain can support. levels that a food chain can support.

Only part of the energy that is stored in Only part of the energy that is stored in one trophic level is passed to the next. one trophic level is passed to the next. This is because organisms use much of This is because organisms use much of the energy that they consume on life the energy that they consume on life processes such as respiration, processes such as respiration, movement, and reproduction.movement, and reproduction.

Only about 10% of the energy at one Only about 10% of the energy at one trophic level is transformed to organisms trophic level is transformed to organisms at the next trophic level.at the next trophic level.

Biomass PyramidBiomass Pyramid The total amount of living tissues within The total amount of living tissues within

a given trophic level. a given trophic level.

Biomass is usually expressed in terms Biomass is usually expressed in terms of grams of organic matter per unit of grams of organic matter per unit area.area.

Represents the amount of potential Represents the amount of potential food available for each trophic level in food available for each trophic level in an ecosystem.an ecosystem.

Pyramid of NumbersPyramid of Numbers

Based on numbers of organisms at each Based on numbers of organisms at each trophic level.trophic level.

Cycles of MatterCycles of Matter 95% of most organisms are made of C, 95% of most organisms are made of C,

H, N, and OH, N, and O

Unlike the one way flow of energy, matter Unlike the one way flow of energy, matter is recycled within and between is recycled within and between ecosystems.ecosystems.

Matter is passed from one organism to Matter is passed from one organism to another through biogeochemical cycles.another through biogeochemical cycles.

Matter is not used up, it is transformed.Matter is not used up, it is transformed.

The Water CycleThe Water Cycle

Water cycles through our environment in Water cycles through our environment in various ways.various ways.

The process by which water changes The process by which water changes from liquid form to an atmospheric gas is from liquid form to an atmospheric gas is called evaporation.called evaporation.

Transpiration – evaporation from the Transpiration – evaporation from the leaves of plants.leaves of plants.

Precipitation – rain, snow, sleet, hailPrecipitation – rain, snow, sleet, hail

The Carbon CycleThe Carbon Cycle