WelcomeWelcome

AP BiologyAP Biology

Summer WorkshopSummer Workshop

July 10th – July 14th July 10th – July 14th

Chapter 50Chapter 50

An Introduction to Ecology An Introduction to Ecology and the Biosphereand the Biosphere

The Scope of EcologyThe Scope of Ecology

The scientific study of interactions The scientific study of interactions between organisms and their between organisms and their environment.environment.

Ecology incorporates the hypothetico-Ecology incorporates the hypothetico-deductive approach, using deductive approach, using observations and experiments to test observations and experiments to test hypothetical explanations.hypothetical explanations.

Ecologists study the interactions Ecologists study the interactions between the between the bioticbiotic and and abioticabiotic environments.environments.

Abiotic ComponentsAbiotic Components

All nonliving chemical and physical All nonliving chemical and physical factors in the environment.factors in the environment.

– LightLight– temperaturetemperature– climate climate – waterwater– nutrientsnutrients– rocks and soilrocks and soil

Biotic FactorsBiotic Factors

All the living factors present in an All the living factors present in an environment.environment.

– AnimalsAnimals– plantsplants– single-celled organismssingle-celled organisms– multi-celled organismsmulti-celled organisms

Aquatic BiomesAquatic Biomes

Aquatic biomes occupy the largest Aquatic biomes occupy the largest area of the biosphere.area of the biosphere.

Major parts of aquatic biomes are:Major parts of aquatic biomes are:• photic zonephotic zone - where sufficient light - where sufficient light

reachesreaches• aphotic zoneaphotic zone - no light reaches - no light reaches• benthic zonebenthic zone - bottom of all aquatic - bottom of all aquatic

biomes made of sand, organic, and biomes made of sand, organic, and inorganic sediments.inorganic sediments.

Aquatic Biomes (con’t)Aquatic Biomes (con’t)

Freshwater Biomes include:Freshwater Biomes include:• Oligotrophic lakesOligotrophic lakes - deep and nutrient poor due - deep and nutrient poor due

to unproductive phytoplankton.to unproductive phytoplankton.• Eutrophic lakesEutrophic lakes - shallow with a high nutrient - shallow with a high nutrient

contentcontent• Rivers and StreamsRivers and Streams - bodies of water - bodies of water

continuously movingcontinuously moving• WetlandsWetlands - are covered with water that - are covered with water that

supports aquatic plantssupports aquatic plants• EstuariesEstuaries - salt and freshwater mix - salt and freshwater mix

Aquatic Biomes (con’t)Aquatic Biomes (con’t)

Marine Biomes include:Marine Biomes include:• Intertidal ZoneIntertidal Zone - exposed to daily tidal - exposed to daily tidal

fluctuations and wave actionfluctuations and wave action• Coral ReefsCoral Reefs - cnidarians secrete a calcium - cnidarians secrete a calcium

carbonate shell that seres as the support carbonate shell that seres as the support for all reef species.for all reef species.

• Oceanic Pelagic BiomeOceanic Pelagic Biome - open ocean where - open ocean where zooplankton feed on phytoplankton which zooplankton feed on phytoplankton which serves as the food source for nekton (free-serves as the food source for nekton (free-swimming)swimming)

Terrestrial BiomesTerrestrial Biomes

Distribution of terrestrial biomes is Distribution of terrestrial biomes is based mainly on regional variations based mainly on regional variations in climate.in climate.

Vertical StratificationVertical Stratification - canopy, low- - canopy, low-tree stratum, shrub understory, tree stratum, shrub understory, ground layer, forest floor, and root ground layer, forest floor, and root layer.layer.

PermafrostPermafrost - permanently frozen soil - permanently frozen soil

Tropical ForestsTropical Forests

Vertical stratificationVertical stratification high rainfallhigh rainfall most biodiverstiymost biodiverstiy nutrient poor soil due to increased nutrient poor soil due to increased

decomposition of dead organic decomposition of dead organic matter by bacteria matter by bacteria

DesertDesert

Sparse rainfall (30 cm or less)Sparse rainfall (30 cm or less) surface temp. above 60 C during surface temp. above 60 C during

the daythe day Plants have adaptations to retain Plants have adaptations to retain

water such as needles, thick waxy water such as needles, thick waxy cuticle, and CAM photosynthesis.cuticle, and CAM photosynthesis.

TundraTundra

High winds and cold temperatures High winds and cold temperatures create alpine tundra plant create alpine tundra plant communities.communities.

Frozen top layer of soilFrozen top layer of soil Little annual rainfallLittle annual rainfall moose and reindeer graze on the moose and reindeer graze on the

small plants and lichenssmall plants and lichens

Principle of AllocationPrinciple of Allocation

An organisms organized way of An organisms organized way of partitioning energy in order to partitioning energy in order to maintain homeostasis.maintain homeostasis.• escape from predatorsescape from predators• obtaining nutrientsobtaining nutrients• growthgrowth• reproductionreproduction• homeostasishomeostasis