COMMUNITIESCOMMUNITIES

BIOLOGICAL COMMUNITY: all the BIOLOGICAL COMMUNITY: all the INTERACTINGINTERACTING populations of different populations of different species that live in the same place at the species that live in the same place at the same time.same time.

LIMITING FACTOR: any biotic or abiotic LIMITING FACTOR: any biotic or abiotic that that RESTRICTSRESTRICTS the existence, number, the existence, number, reproduction, or distribution of organisms.reproduction, or distribution of organisms.

COMMUNITIESCOMMUNITIES

TOLERANCE: the ability of an organism TOLERANCE: the ability of an organism to withstand (or to withstand (or TOLERATETOLERATE) fluctuations in ) fluctuations in biotic and abiotic environmental factors.biotic and abiotic environmental factors.

SUCCESSIONS: the orderly, natural SUCCESSIONS: the orderly, natural CHANGESCHANGES and species replacements that and species replacements that take place in the communities of the take place in the communities of the ecosystem.ecosystem.

COMMUNITIESCOMMUNITIESTWO TYPES OF SUCCESSIONTWO TYPES OF SUCCESSION

PRIMARY SUCCESSION: the colonization PRIMARY SUCCESSION: the colonization of of BARREN LANDBARREN LAND by communities of by communities of organisms.organisms. CLIMAX COMMUNITY: communities of CLIMAX COMMUNITY: communities of organisms become organisms become STABLESTABLE, and reaches an , and reaches an EQUILIBRIUMEQUILIBRIUM..

COMMUNITIESCOMMUNITIESTWO TYPES OF SUCCESSIONTWO TYPES OF SUCCESSION

SECONDARY SUCCESSION: the SECONDARY SUCCESSION: the sequence of changes that takes place after sequence of changes that takes place after an existing community is severely an existing community is severely DISTURBEDDISTURBED in some way. in some way. Example: 1988 forest fire of Yellowstone Example: 1988 forest fire of Yellowstone National ParkNational Park

fire → wildflowers → shrubs → trees → insects fire → wildflowers → shrubs → trees → insects → → animalsanimals

BIOMESBIOMESReview:Review: BIO: Greek (BIO: Greek (biotikosbiotikos) = ) = LIFELIFE!! BIOTIC: pertaining to life or BIOTIC: pertaining to life or LIVING LIVING THINGS.THINGS. ABIOTIC: (“a” = NOT) ABIOTIC: (“a” = NOT) NON-LIVINGNON-LIVING component of the environment.component of the environment. BIODIVERSITY: “The BIODIVERSITY: “The VARIETYVARIETY of life”! of life”! INDIGENOUS: INDIGENOUS: NATIVENATIVE to (originated to (originated from) a particular place.from) a particular place.

BIOMESBIOMES BIOMES: A large group of BIOMES: A large group of ECOSYSTEMSECOSYSTEMS

that share the same type of that share the same type of CLIMAXCLIMAX community. Two types: community. Two types: terrestrialterrestrial & & aquaticaquatic

AQUATIC:AQUATIC: (in water)(in water) Examples: marine, Examples: marine, estuaries, intertidal zones, freshwater, estuaries, intertidal zones, freshwater, wetlands, swamps, marshes, and bogs.wetlands, swamps, marshes, and bogs.

TERRESTRIAL: (on land) Examples: TERRESTRIAL: (on land) Examples: tundra, taiga, desert, grassland, temperate tundra, taiga, desert, grassland, temperate forest, and tropical forest.forest, and tropical forest.

BIOMESBIOMESWORLD’S MAJOR BIOMESWORLD’S MAJOR BIOMES

DESERTDESERTFORESTFOREST

GRASSLANDGRASSLANDTUNDRATUNDRA

TAIGATAIGACHAPARRALCHAPARRAL

FRESHWATERFRESHWATERMARINEMARINE

BIOMESBIOMES

DESERTDESERT

BIOMESBIOMES

FORESTFOREST

Deciduous Deciduous Tropical RainTropical Rain

BIOMESBIOMES

GRASSLANDGRASSLAND

BIOMESBIOMES

TUNDRATUNDRA

BIOMESBIOMES

TAIGATAIGA

BIOMESBIOMES

CHAPARRALCHAPARRAL

BIOMESBIOMES

FRESHWATERFRESHWATER

BIOMESBIOMES

MARINEMARINE

Terrestrial BiomesTerrestrial Biomes

Aquatic BiomesAquatic Biomes

www.learner.org

ClimographsClimographs

DESERTDESERT

© Billy Price http://rrms-biomes.tripod.com

Spadefoot Toad

JackrabbitDingo

Climate & Soils: Very dry; hot days & cold nights; rainfall less than 10 in/year (25 cm/year). Soils are thin and porous..Dominant Vegetation: Widely scattered thorny bushes & shrubs, cactiDominant Animal Life: Rodents, lizards, snakes, numerous insects, owls, hawks, small birds, dingo, jackrabbit, toadsGeographic Distribution: North & Southwest Africa, parts of Middle East & Asia, Southwest United States, Northern Mexico

DESERTDESERT

4th Trophic Level:Tertiary Consumers - CarnivoresThese are high level consumers, carnivores that will eat other carnivores.

1st Trophic Level: Primary Producers - Plants

These are plants that make food through

photosynthesis. Including: Trees, shrubs, cactus,

wildflowers, grasses2nd Trophic Level: Primary Consumers - HerbivoresThese animals are usually small and eat little. Including: Ants and other insects, rats and mice,

some reptiles.

3rd Trophic Level: Secondary Consumers - Small Carnivores

The predators are the secondary consumers. They occupy the third trophic level. Again we see cold-blooded animals, such as snakes, insect-eating lizards, and tarantulas. In the harsher desert environments, they are the top predators.

DESERTDESERTInteresting Facts:

The Gobi Desert in Asia is cold for most of the year. Mountains on the edge of deserts prevent rain from entering. The rain stays on the other side of the mountain creating rain forests next to many deserts. These deserts are called rain shadows. The world's deserts are growing through desertification. This happens when grasslands that border the desert become as dry as the desert. Desertification can also be caused by intense farming. The cactus can store gallons of water in their stems and trunksThe jackrabbits abnormally large ears allow it to relieve heatKangaroo rats take water from the food they eat, thus, they never have to drink.

ClimatographClimatograph

www.uwsp.edu

www.drought.unl.edu

El Paso, TX

Note:

35 C = 95 F

15 C = 59 F

350 mm = 13.8 in.

150 mm = 6 in.

FORESTFORESTDeciduousDeciduous

• Ave. annual temperature = 10C (50F)Ave. annual temperature = 10C (50F)• Rainfall = 30-60 inches a yearRainfall = 30-60 inches a year• Five different zones. These zones are Five different zones. These zones are

the Tree Stratum Zone, Small Tree the Tree Stratum Zone, Small Tree and Sapling Zone, the Shrub Zone, the and Sapling Zone, the Shrub Zone, the Herb Zone, and the Ground Zone.Herb Zone, and the Ground Zone.

• Four distinct seasons. Four distinct seasons. • In fall and winter, the trees lose their In fall and winter, the trees lose their

leaves.leaves.

• Plants use the forest’s nutrients by leaning toward the sun and absorbing the nutrients from the ground.

• Many deciduous forests have lost land due to habitat destruction (farms and towns that are built).

• Always located in temperate zones above tropical forests and below coniferous forests.

• Animals are usually acorn feeders or omnivores.

www.world-builders.org

Tertiary Consumers =Cougars, bears

Secondary Consumers=Foxes, owls, opossums, birds, skunks

Primary Consumers=Deer, rodents, birds, insects

Primary Producers=Fruit trees, berry bushes, fungi, ferns

The tropical rain forest is a forest of The tropical rain forest is a forest of tall trees in a region of year-round tall trees in a region of year-round warmth. Almost all tropical rain warmth. Almost all tropical rain forests are near the equator. Rain forests are near the equator. Rain forests cover 6% of the Earth’s land forests cover 6% of the Earth’s land surface.surface.

Average Rainfall and TemperatureAverage Rainfall and TemperatureAn average rainfall in a tropical rain An average rainfall in a tropical rain forest is 95 in/yr.forest is 95 in/yr. The average temperature about 28 The average temperature about 28 degrees Celsiusdegrees CelsiusThe temperature in a rain forest The temperature in a rain forest rarely gets higher than 93 °F (34 °C) rarely gets higher than 93 °F (34 °C) or drops below 68 °F (20 °C)or drops below 68 °F (20 °C)

RainforestRainforestTemperateTemperate TropicalTropical

• Temperate evergreen forests include diverse vegetation, animal life and can be found all over the world. The summers are dry and all the trees are conifers.

Average Rainfall and Temperature

•Average rainfall: 60 - 200 in/yr.

•The temperature varies below freezing in the winter, and up to 80 deg. F in summer.

• Some of the animals include squirrels, rabbits, mountain lion, bobcat and fox.

• Coniferous forests are the largest land biome in the world.

Places in the World

• Tropical: Most are located in South America, West Africa, and Southeast Asia. Almost all rainforests are near or on the equator.

•Temperate: East Asia, Australia, New Zealand, western edge of North and South America. Climate usually portrays proximity to ocean.

Interesting Facts:

• Climate usually portrays proximity to the ocean

•Wildfires are uncommon because of constant high moisture content

•Unlike tropical rain forests, temperate rain forests have seasonal variations

Tertiary Consumers =Lynx, wolves, bears, cougars

Secondary Consumers=Shrew, amphibians, weasels, raccoons, insects, birds

Primary Consumers=Salmon, insects, deer, elk, birds, chipmunks, squirrels, voles

Primary Producers=Ferns, mosses, shrubs, mushrooms

Temperate Rain Forest

Interesting Facts:

• About 1/4 of the medicines come from the tropical rain forest• More than half of the animals and plant species are living in the rain forest.• More than 1,400 varieties of tropical plants are thought to be potential cures for cancer.

Tertiary Consumers =Jaguars, tigers, snakes,

Secondary Consumers= Reptiles, amphibians, bats, insects, birds

Primary Consumers=Monkeys, birds, insects, small mammals

Primary Producers=Vines, epiphytes, flowering plants, Both canopy and understory trees

Tropical Rain Forest

Rainforest ClimatographRainforest ClimatographTropicalTropical TemperateTemperate

Vancouver, CanadaRio de Janeiro, Brazilwww.drought.unl.edu

TAIGA (Boreal Forest)TAIGA (Boreal Forest) • The Northern coniferous forest or boreal forest often called Taiga developed in cooler and drier regions as do temperate forests.

• They experience long, cold winters and short, cool summers.

•It consists of evergreen trees that dominate large parts on the forest interspersed with occasional bogs and lakes.

•Soils are typically young, nutrient-poor and somewhat acidic. As a result of the strong seasonal variation in day length, temperature and precipitation, many organisms compile a year’s worth of feeding, breeding, and rearing a young into a few warm, wet months.

• Stretch across much of Canada, Alaska, Russia and Scandinavia.

TAIGAAverage Rainfall and Temperature• Winter's LOWEST temperature in taiga is -65°F.• Winter's HIGHEST temperature is 30° F.• Summer's LOWEST temperature is 30° F• Summer's HIGHEST temperature is 70° F• The average rainfall in Taiga is about 23.88 cm per month.

Interesting Facts

• There are 2 types of Boreal Forest 1) Open woodland and 2) dense forest.

• The world’s largest terrestrial forest.

• Since the northern areas were once connected North America and Eurasia were once connected by land bridges during past ice ages, the animals and vegetations of the boreal have been able to spread widely.

• Boreal Forests have some of the Earth’s largest wilderness areas that remain.

• Fur bearing animals of boreal have been of commercial value, lately this value has drooped due to Western nation’s concern of the animal’s welfare.

TAIGA FOOD WEB

GRASSLANDGRASSLAND

• The grassland biome consists of areas of land in which are to dry for forests and to wet for deserts.

• Grasslands and the many species they support occupy 25% of all land area.

• The grasslands have been exploited by agricultural farmers for their rich soils in which can be used for successfully growing mass amounts of crops in one area.

• Sometimes called prairies, savannahs or steppes.

Indigenous Plants and Animals• Dominant animal species consist of elephants, wildcats, antelopes, buffalo, horse, rabbits, leopards, eagles, pumas, and kangaroos.

• Dominant plants consist of many different kinds of grasses, perennials, and extensively developed roots.

• Grasslands are located North of the Trophic of Cancer and South of the Trophic of Capricorn.• Grasslands are located in many parts of the world. In America they are located in the North Central and Eastern United States.• Grasslands are also located in other countries and continents such as Mongolia, Russia, Argentina, Uruguay, Brazil, Africa, Madagascar, Australia, and New Zealand. • Average temperature in summer:104°F• Average temperature in winter: -40°F• Average amount of rainfall:10-30 inches

• Early settlers referred to the grasslands as “prairies” and thought they were dry and flat areas, but realized they contained 80 different species of animals and 300 species of birds.• Grasslands are considered a transitional biome, which means there are found between the desert and forests.

TUNDRATUNDRA

The word tundra derives from the Finnish word for barren or treeless land. The tundra is the simplest biome in terms of species composition and food chains.

• Dominant vegetation: low-growing sedges, dwarf shrubs, lichens mosses, and grasses (producers)

• Plants are accustomed to sweeping winds and soil disturbance

•Birds use the scrubs for nests

•Dominant animal life: year-round lemmings, arctic hares (primary consumers), arctic foxes (secondary consumers), lynx, caribou, musk ox; summers: abundant insects, many migrant shorebirds, geese,

ducks, pikas.

Distribution: The tundra biome is restricted to the high latitudes of the northern hemisphere in a belt around the Arctic Ocean. Many of its species, both plant and animal, have circumpolar distribution areas.

• Extremely short growing season (6 to 10 weeks)• Long, cold, dark winters (6 to 10 months with mean monthly temperatures below 32 ｡ F or 0 ｡ C.)• Low precipitation (less than five inches/year) coupled with strong, drying winds. • Snowfall is actually advantageous to plant and animal life as it provides an insulating layer on the ground surface.

www.world-builders.org

Interesting Facts:

• Permafrost-permanently frozen subsoil

•Among the Earth’s coldest, harshest biomes

•Black flies and mosquitoes are abundant.

•Tundra are vulnerable to habitat destruction, over-hunting, and extinction through loss of any of the plant or animal species

CHAPARRALCHAPARRAL• Mediterranean scrub and woodlands, some examples are flatlands, rocky hills and mountain slopes.

• Chaparral is characterized as being very hot and dry, since they are only found in some terrains like flat plains, rocky hills and mountain slopes.

• During the summer fires and droughts are very common due to the terrain and climate. Plants and animals who live in these area have adapted to the conditions many plants have small, hard leaves which hold moisture.

•Most animals are mainly grassland and desert types adapted to the hot, dry terrain.

• Due to the adaptations the trees produce flammable aromatic oils that are prone to frequent fires.

Location

   Mediterranean Coast

   Coastal California, Los Angeles and San Francisco

   South Australia

   Parts of South Africa

http://cougarbiology.pbworks.com

Annual Precipitation: Less than 300 mm (12 to 17 inches) of rainfall yearly mostly during the winter. This is due to long, dry periods in the summer

-Annual Temperature: 59 degrees F in summer, 46

degrees F in winter

Los Angeles, CACHAPARRAL

http://www.worldexecutive.com

BIODIVERSITY & CONSERVATIONBIODIVERSITY & CONSERVATION

BIODIVERSITYBIODIVERSITY: variety of species in a : variety of species in a specific area.specific area.Biodiversity increases as you move towards Biodiversity increases as you move towards the the EQUATOREQUATOR.. IMPORTANCE OF BIODIVERSITY:IMPORTANCE OF BIODIVERSITY:

a. a. TO NATURETO NATURE – living things are – living things are interdependentinterdependent

b. b. BRINGS STABILITYBRINGS STABILITY: as long as their : as long as their diversity is diversity is maintained maintained

c. c. TO PEOPLETO PEOPLE: preserving biodiversity : preserving biodiversity ensures there will be a supply of living things.ensures there will be a supply of living things.

BIODIVERSITY & CONSERVATIONBIODIVERSITY & CONSERVATION

EXTINCTIONEXTINCTION: the disappearance of a species: the disappearance of a species

Only those species that can Only those species that can ADAPTADAPT will will escape extinction.escape extinction.

The The FOSSILFOSSIL record show that extinctions record show that extinctions have occurred many times. have occurred many times.

ENDANGERED SPECIESENDANGERED SPECIES: species numbers : species numbers are so low extinction is possible.are so low extinction is possible.

THREATENED SPECIESTHREATENED SPECIES: a species is likely : a species is likely to become endangered.to become endangered.

BIODIVERSITY & CONSERVATIONBIODIVERSITY & CONSERVATION

THREATS TO BIODIVERSITYTHREATS TO BIODIVERSITY

HABITAT LOSS: one of the biggest HABITAT LOSS: one of the biggest reasons for decline in biodiversity!reasons for decline in biodiversity!

HABITAT FRAGMENTATION: the HABITAT FRAGMENTATION: the separation of wilderness areas for other separation of wilderness areas for other wilderness areaswilderness areas

As new species MIGRATE to an area, As new species MIGRATE to an area, overall species diversity declines.overall species diversity declines.

BIODIVERSITY & BIODIVERSITY & CONSERVATIONCONSERVATION

THREATS TO BIODIVERSITYTHREATS TO BIODIVERSITY

GEOGRAPHICGEOGRAPHIC isolation can lead to isolation can lead to GENETICGENETIC isolation. isolation.

EDGE EFFECTEDGE EFFECT: “edges” an ecosystem : “edges” an ecosystem can have two different abiotic factors.can have two different abiotic factors.

(Ex. housecats in suburbia threaten (Ex. housecats in suburbia threaten native nesting birds.)native nesting birds.)

BIODIVERSITY & CONSERVATIONBIODIVERSITY & CONSERVATION

THREATS TO BIODIVERSITYTHREATS TO BIODIVERSITY

HABITAT DEGRADATIONHABITAT DEGRADATION: damage to a : damage to a habitat by pollutionhabitat by pollutiona. a. waterwater pollution (ex. detergents, heavy pollution (ex. detergents, heavy metals, ASARCO)metals, ASARCO)b. b. landland pollution (ex. DDT, ASARCO) pollution (ex. DDT, ASARCO)

EXOTIC SPECIESEXOTIC SPECIES: a species that is : a species that is NOT NATIVE to a particular area. NOT NATIVE to a particular area. (introduced or invasive)(introduced or invasive)

BIODIVERSITY & CONSERVATIONBIODIVERSITY & CONSERVATION

CONSERVATION OF BIODIVERSITYCONSERVATION OF BIODIVERSITY

CONSERVATION BIOLOGYCONSERVATION BIOLOGY: study and : study and implementation of methods to protect implementation of methods to protect biodiversity.biodiversity.

NATURAL RESOURCESNATURAL RESOURCES: parts of the : parts of the environment that are useful are environment that are useful are necessary for living organisms.necessary for living organisms.

Human Effect on BiodiversityHuman Effect on Biodiversity

Most of these extinctions have occurred on islands.

Habitat DestructionHabitat DestructionCauses:OverpopulationDeforestationPollution (air, water, soil)Global Warming (climate change)

http://www.defenders.org

Ex: Mexican gray wolf (Canis lupus baileyi) “El lobo” Humans and habitat destruction pose the greatest threat to Mexican wolves. Endangered, Species Protection Plan (SPP) 2011 Update - Population of endangered Mexican gray wolves has grown for the first time in four years, up to at least 50 wolves and 2 breeding pairs in the wild – a near 20 percent increase from this time last year.

Invasive or Introduced SpeciesInvasive or Introduced Species Invasive species Invasive species = one that has been introduced and = one that has been introduced and

become a pest in its new location, spreading (invading) become a pest in its new location, spreading (invading) by natural means. by natural means. Barriers such as large rivers, seas, oceans, Barriers such as large rivers, seas, oceans,

mountains and deserts encourage diversity by mountains and deserts encourage diversity by enabling independent evolution on either side of the enabling independent evolution on either side of the barrier. barrier.

Invasive species occur when those barriers are Invasive species occur when those barriers are blurred. blurred.

Without barriers such species occupy new niches, Without barriers such species occupy new niches, substantially reducing diversity.substantially reducing diversity.

Invasive or Introduced SpeciesInvasive or Introduced Species

Introduced species Introduced species = a species living outside = a species living outside its native distributional range, which has its native distributional range, which has arrived there by human activity, either arrived there by human activity, either deliberate or accidental. deliberate or accidental.

Not all introduced species are invasive, nor Not all introduced species are invasive, nor all invasive species deliberately introducedall invasive species deliberately introduced

Invasive or Introduced SpeciesInvasive or Introduced Species IntentionalIntentional::

Fish and game for recreation and hunting (rabbits Fish and game for recreation and hunting (rabbits in AUS, carp)in AUS, carp)

Plants for sentimental or aesthetic appeal Plants for sentimental or aesthetic appeal (ornamental plants)(ornamental plants)

Domestic pets (Feral cats and parrots)Domestic pets (Feral cats and parrots) Reintroduction (Gray wolf in Yellowstone)Reintroduction (Gray wolf in Yellowstone) Food source (apple snail as protein source in HI)Food source (apple snail as protein source in HI) Environmental and biological control (Kudzu as Environmental and biological control (Kudzu as

erosion control)erosion control)

Invasive or Introduced SpeciesInvasive or Introduced Species

Unintentional/AccidentalUnintentional/Accidental:: Rats hitchhike on shipsRats hitchhike on ships Zebra musselZebra mussel Africanized honey bees “killer bees”Africanized honey bees “killer bees” Fire antsFire ants

Levels of organization of matter:Levels of organization of matter:UniverseUniversePlanetsPlanets

Ecosphere/BiosphereEcosphere/BiosphereEcosystems (abiotic and Ecosystems (abiotic and

biotic)biotic)Communities (many species)Communities (many species)

Populations (one species)Populations (one species)Organisms (one individual)Organisms (one individual)

Organ Systems/OrgansOrgan Systems/OrgansCellsCells

AtomsAtoms

Trophic CategoriesTrophic CategoriesProducers (autotrophs) Producers (autotrophs) - create their - create their own food through photosynthesis; own food through photosynthesis; plants, algae and some bacteria.plants, algae and some bacteria.Consumers (heterotrophs)Consumers (heterotrophs) – cannot – cannot create their own food, must obtain create their own food, must obtain energy from the food they eat energy from the food they eat (producers or other consumers). (producers or other consumers).

Trophic Categories cont.Trophic Categories cont. Detritus feeders Detritus feeders – consume – consume

detritus and aide in detritus and aide in decomposition.decomposition.

Example: earthworm and Example: earthworm and some beetlessome beetles

Decomposers – digest the Decomposers – digest the detritus more fully and create detritus more fully and create inorganic material (breaking the inorganic material (breaking the carbon bonds.)carbon bonds.)

Example: bacteria and fungiExample: bacteria and fungi

Food ChainFood Chain Food Chain = shows simple Food Chain = shows simple

feeding relationships (begin feeding relationships (begin with producers)with producers) Quaternary consumer or Quaternary consumer or

“fourth order”“fourth order” Tertiary consumer or Tertiary consumer or

“third order”“third order” Secondary consumer or Secondary consumer or

“second order”“second order” Primary consumer or “first Primary consumer or “first

order”order” Primary producerPrimary producer

Biomass and Biomass PyramidBiomass and Biomass Pyramid

All biomass gets its energy from the sunAll biomass gets its energy from the sun Only 10% of energy from one trophic level Only 10% of energy from one trophic level

moves to the next trophic levelmoves to the next trophic level Energy released, low on the Biomass Pyramid, Energy released, low on the Biomass Pyramid,

is high potential energy molecules (like glucose) is high potential energy molecules (like glucose) then converted to low potential energy then converted to low potential energy molecules (like carbon dioxide) higher on the molecules (like carbon dioxide) higher on the Pyramid.Pyramid.

Understand the concept of eating lower on the Understand the concept of eating lower on the biomass pyramid biomass pyramid

Energy PyramidsEnergy Pyramids

Biomass PyramidsBiomass Pyramids

Primary Succession

CompetitionCompetition Intraspecific Intraspecific

competitioncompetition: competition : competition among members of the among members of the samesame species species

Interspecific Interspecific competitioncompetition: competition : competition among members of among members of differentdifferent species species

Species InteractionsSpecies Interactions PREDATIONPREDATION = the use of one species as a = the use of one species as a

resource by another species; an organism resource by another species; an organism that feeds directly upon another living that feeds directly upon another living organism, whether or not it kills the prey organism, whether or not it kills the prey to do so.to do so.

1. True predators: kill prey and consume 1. True predators: kill prey and consume most of what they killmost of what they kill

2. Carnivore/Omnivore/Herbivore2. Carnivore/Omnivore/Herbivore

3. Parasites: live on or in organism (the 3. Parasites: live on or in organism (the host)host)

a.a. Pathogens – cause disease in their Pathogens – cause disease in their host (e.g. viruses, bacteria, protists)host (e.g. viruses, bacteria, protists)

Predation cont.Predation cont.

4. Parasitoids: lay eggs inside other 4. Parasitoids: lay eggs inside other organisms. When eggs hatch, larvae organisms. When eggs hatch, larvae slowly consume the host from the inside slowly consume the host from the inside out (e.g. parasitic wasps and flies)out (e.g. parasitic wasps and flies)

Exceptions include scavengers, Exceptions include scavengers, detritivores, and decomposers (which feed detritivores, and decomposers (which feed on dead things)on dead things)

Species InteractionsSpecies Interactions

Keystone SpeciesKeystone Species: : plays a critical role in maintaining the structure of an plays a critical role in maintaining the structure of an

ecological community and ecological community and whose impact on the community is greater than would be whose impact on the community is greater than would be

expected based on its relative abundance or total biomass.expected based on its relative abundance or total biomass.

Species InteractionsSpecies Interactions

The sea otter Enhydra lutris, can be considered a keystone predator because its voracious feeding on herbivorous sea urchins allows kelps to flourish along the rocky coast, along with an entire ecosystem associated with these large marine plants. Photo by Matt Knoth. (Source: Wikimedia Commons)

The sea star Pisaster ochraceus, the original keystone species, feeds preferentially on mussels on northeast Pacific rocky shores. By doing so, the predatory sea star prevents mussels from taking over the entire shore and allows less competitive species to persist, thus enhancing local species diversity. (Source: Multi-Agency Rocky Intertidal Network)

MutualismMutualism

www.asknature.org

http://fybiology.tumblr.com http://adventuresinscience.edublogs.org

CommensalismCommensalism

king.portlandschools.org

http://www.cals.ncsu.eduhttp://scienceline.org

http://animalreview.wordpress.com