Introduction To Introduction To EcologyEcology

Ch. 50Ch. 50

Introduction To EcologyIntroduction To Ecology

EcologyEcology – the scientific study of the – the scientific study of the interactions between organisms and their interactions between organisms and their environmentsenvironments

Ecology determines both the distribution and Ecology determines both the distribution and abundance of organismsabundance of organisms

Distribution and abundance depends on Distribution and abundance depends on abioticabiotic (non-living factors such as temperature, light, (non-living factors such as temperature, light, water, nutrients, pH, etc.) and water, nutrients, pH, etc.) and bioticbiotic (living (living factors such as all the living organisms) factors such as all the living organisms) components of the environmentcomponents of the environment

Levels of Ecological StudyLevels of Ecological Study

1.1. Organismal Ecology – morphological, Organismal Ecology – morphological, physiological, and behavioral way in which physiological, and behavioral way in which individual organisms meet the challenges individual organisms meet the challenges posed by their abiotic and biotic posed by their abiotic and biotic environmentsenvironments

Levels of Ecological StudyLevels of Ecological Study

A A populationpopulation is a group of individuals of the is a group of individuals of the same species living in a particular geographic same species living in a particular geographic areaarea

Population EcologyPopulation Ecology – – factors that affect how factors that affect how many individuals of a many individuals of a particular species live in particular species live in an area an area

Levels of Ecological StudyLevels of Ecological Study

A A communitycommunity consists of all the organisms of consists of all the organisms of all the species that inhabit a particular area; it all the species that inhabit a particular area; it is an assemblage of populations of many is an assemblage of populations of many different speciesdifferent species

3.3. Community EcologyCommunity Ecology – the whole array of – the whole array of interacting species interacting species in a community in a community (includes predation, (includes predation, competition, and competition, and disease)disease)

Levels of Ecological StudyLevels of Ecological Study

An An ecosystemecosystem consists of all the abiotic consists of all the abiotic factors in addition to the entire community of factors in addition to the entire community of a species that exist in a certain area; may a species that exist in a certain area; may consist of many different communitiesconsist of many different communities

4.4. Ecosystem EcologyEcosystem Ecology – the – the emphasis in on the energy flow emphasis in on the energy flow and the cycling of chemicals and the cycling of chemicals among the various biotic and among the various biotic and abiotic componentsabiotic components

Levels of Ecological StudyLevels of Ecological Study The The BiosphereBiosphere is the global ecosystem, the is the global ecosystem, the

layer of Earth inhabited by life; the sum of all layer of Earth inhabited by life; the sum of all the plant’s ecosystemsthe plant’s ecosystems

Factors Affecting DistributionFactors Affecting Distribution Biogeography Biogeography – the study of the past and present – the study of the past and present

distribution of individual speciesdistribution of individual species In studying the In studying the dispersal dispersal of organisms, ecologists of organisms, ecologists

work through a series of logical steps to work through a series of logical steps to determine what limits geographical distributionsdetermine what limits geographical distributions

Factors Affecting DistributionFactors Affecting Distribution Of course, we do not want to purposely Of course, we do not want to purposely

introduce organisms to areas where they introduce organisms to areas where they do not already existdo not already exist

Examples – African Honeybee Examples – African Honeybee (purposely) and Zebra Mussel (purposely) and Zebra Mussel (accidentally)(accidentally)

Tens RuleTens Rule – one out of ten introduced – one out of ten introduced species becomes established, and one species becomes established, and one out of ten established species become out of ten established species become common enough to become pests.common enough to become pests.

Factors Affecting DistributionFactors Affecting Distribution Behavior and habitat selectionBehavior and habitat selection

Habitat selection by ovipositing insects, Habitat selection by ovipositing insects, which often choose only certain host which often choose only certain host plants, may limit their distributionplants, may limit their distribution

Biotic FactorsBiotic Factors The inability to survive and reproduce may The inability to survive and reproduce may

be due to predation, disease, or be due to predation, disease, or competitioncompetition

Abiotic FactorsAbiotic Factors Temperature, water, sunlight, wind, and Temperature, water, sunlight, wind, and

rocks and soilrocks and soil

Factors Affecting DistributionFactors Affecting Distribution Temperature and moisture are the major Temperature and moisture are the major

climatic factors determining distributionclimatic factors determining distribution ClimateClimate is the prevailing weather conditions is the prevailing weather conditions

of a locality and are influenced by of a locality and are influenced by temperature, water, temperature, water, light, and windlight, and wind

Biomes Biomes are major are major types of ecosystems types of ecosystems found in broad found in broad geographic regionsgeographic regions

Solar Radiation and LatitudeSolar Radiation and Latitude

What Causes Seasons?What Causes Seasons?

Lake Stratification and Lake Stratification and Seasonal Turnover Seasonal Turnover

Aquatic BiomesAquatic Biomes Freshwater biomes – less than 1% salt Freshwater biomes – less than 1% salt

concentrationconcentration Marine biomes – average of 3% salt Marine biomes – average of 3% salt

concentrationconcentration Oceans influence global rainfall, climate, and Oceans influence global rainfall, climate, and

wind patternswind patterns Marine algae and photosynthetic bacteria Marine algae and photosynthetic bacteria

produce a large portion of the world’s oxygen produce a large portion of the world’s oxygen and consume enormous amounts of carbon and consume enormous amounts of carbon dioxidedioxide

Aquatic BiomesAquatic Biomes

Freshwater BiomesFreshwater Biomes

FreshwaterFreshwater Biomes Biomes

An Oligotrophic Lake

A Eutrophic Lake

A River

Freshwater BiomesFreshwater Biomes WetlandsWetlands – areas covered with water and – areas covered with water and

supporting hydrophytes (water plants); range supporting hydrophytes (water plants); range from marshes to swamps to bogsfrom marshes to swamps to bogs

These richly diverse biomes are important to These richly diverse biomes are important to flood control and water qualityflood control and water quality

Freshwater BiomesFreshwater Biomes EstuariesEstuaries – where a freshwater river or – where a freshwater river or

stream meets the ocean; often bordered by stream meets the ocean; often bordered by wetlands called mudflats and saltmarsheswetlands called mudflats and saltmarshes

Serve as feeding and breeding areas for marine Serve as feeding and breeding areas for marine invertebrates, fish, and waterfowlinvertebrates, fish, and waterfowl

Marine BiomesMarine Biomes

Marine BiomesMarine Biomes Intertidal zonesIntertidal zones – the daily cycle of tides – the daily cycle of tides

exposes the shoreline to variations in water, exposes the shoreline to variations in water, nutrients, and temperature, and to the nutrients, and temperature, and to the mechanical force of wave actionmechanical force of wave action

Rocky intertidal zonesRocky intertidal zones have have organisms adapted to firmly organisms adapted to firmly attach to the hard substrateattach to the hard substrate

Sand or mudflat intertidal zones Sand or mudflat intertidal zones are home to burrowing worms, are home to burrowing worms, clams, and crustaceansclams, and crustaceans

Marine BiomesMarine Biomes Coral reefsCoral reefs – found in – found in

tropical waters in the tropical waters in the nertic zone; are highly nertic zone; are highly diverse and productive diverse and productive biomesbiomes

Coral reefs are easily Coral reefs are easily damaged by pollution, damaged by pollution, development, native development, native and introduced and introduced predators, and high predators, and high water temperatureswater temperatures

Marine BiomesMarine Biomes BenthosBenthos – nutrients reach the benthic zone – nutrients reach the benthic zone

as detritus falling from the waters above.as detritus falling from the waters above. Nertic benthic communities receive sunlight and Nertic benthic communities receive sunlight and

are very diverse and productiveare very diverse and productive Various invertebrates and fishes that are adapted Various invertebrates and fishes that are adapted

to cold, dark, and high water pressure inhabit the to cold, dark, and high water pressure inhabit the abyssal zoneabyssal zone

Chemoautotrophic Chemoautotrophic prokaryotes are adapted prokaryotes are adapted to the hot, low-oxygen to the hot, low-oxygen environment surrounding environment surrounding deep-sea hydrothermal deep-sea hydrothermal ventsvents

Terrestrial BiomesTerrestrial Biomes

Terrestrial BiomesTerrestrial Biomes The geographic distribution of the world’s The geographic distribution of the world’s

major terrestrial biomes is related to abiotic major terrestrial biomes is related to abiotic factors – in particular, the prevailing climatefactors – in particular, the prevailing climate

Biomes are usually named for their Biomes are usually named for their predominant vegetation and major climatic predominant vegetation and major climatic featuresfeatures

Each bio also has characteristics Each bio also has characteristics microorganisms, fungi, and animalsmicroorganisms, fungi, and animals

Tropical ForestsTropical Forests Occur within 23Occur within 23°° latitude of the equator latitude of the equator Variation in rainfall result in tropical dry Variation in rainfall result in tropical dry

forests, tropical deciduous forests, and forests, tropical deciduous forests, and tropical rain forests, where rainfall is tropical rain forests, where rainfall is abundantabundant

SavannaSavanna Tropical and subtropical grassland with Tropical and subtropical grassland with

scattered trees and rainy and dry seasonsscattered trees and rainy and dry seasons Fires and large grazing mammals restrict Fires and large grazing mammals restrict

vegetation to grasses and small broad-leaved vegetation to grasses and small broad-leaved plantsplants

DesertsDeserts Characterized by low and unpredictable Characterized by low and unpredictable

precipitationprecipitation May be hot or cold depending on locationMay be hot or cold depending on location Desert animals have physiological and Desert animals have physiological and

behavioral adaptations to dry conditionsbehavioral adaptations to dry conditions Plants may use Plants may use

CAM photosynthesis CAM photosynthesis and have water and have water storage adaptations storage adaptations and protective spines and protective spines and poisonsand poisons

ChaparralChaparral Common along coastlines in midlatitudes that Common along coastlines in midlatitudes that

have mild, rainy winters and hot, dry have mild, rainy winters and hot, dry summerssummers

The dominant vegetation – dense, spiny The dominant vegetation – dense, spiny evergreen shrubs – is maintained by and evergreen shrubs – is maintained by and adapted to periodic firesadapted to periodic fires

Temperate GrasslandsTemperate Grasslands Maintained by fire, seasonal drought, and Maintained by fire, seasonal drought, and

grazing by large mammalsgrazing by large mammals Soils are deep and rich in nutrientsSoils are deep and rich in nutrients

Temperate Deciduous ForestsTemperate Deciduous Forests Characterized by broad-leaved deciduous Characterized by broad-leaved deciduous

treestrees Grow in midlatitude regions that have Grow in midlatitude regions that have

adequate moisture to support the growth of adequate moisture to support the growth of large treeslarge trees

Trees drop Trees drop their leaves their leaves before winterbefore winter

Coniferous Forest (Taiga)Coniferous Forest (Taiga) A large biome found in northern latitudesA large biome found in northern latitudes Characterized by harsh winters with heavy Characterized by harsh winters with heavy

snowfallsnowfall Coniferous trees grow in dense, uniform Coniferous trees grow in dense, uniform

standsstands Coastal Coastal

temperate rain temperate rain forests area forests area also coniferous also coniferous forestsforests

TundraTundra The northernmost limit of plant growthThe northernmost limit of plant growth Characterized by dwarfed or mat-like Characterized by dwarfed or mat-like

vegetationvegetation The alpine tundra, found at all latitudes on The alpine tundra, found at all latitudes on

high mountains above the tree line, has high mountains above the tree line, has similar flora and fauna similar flora and fauna

The artic tundra has a shallow root layer due The artic tundra has a shallow root layer due to permafrost, to permafrost, permanently permanently frozen soilfrozen soil