Environmental science chapter 6

and 7

Environmental science chapter 6

and 7

Communities, Biomes, & Population

Biology

Communities, Biomes, & Population

Biology

I.I. Limiting Limiting FactorsFactors

- factors that affect an organism's ability to survive in its environment

- temperature, rainfall, fire, food, predators, etc.

A.A. Optimum Range:Optimum Range:- area with fewest limiting

factorsB.B. Range of Tolerance:Range of Tolerance:

- area with a few limiting factors

C.C. Zone of Stress:Zone of Stress:- area with several limiting factor

Optimum Optimum RangeRange

**

Range of ToleranceRange of Tolerance

Optimum RangeOptimum Range

Distribution Distribution ofof

Douglas-firDouglas-fir

MicroclimateMicroclimate

II.II. Ecological Ecological SuccessionSuccession

Mount St. HelensMount St. Helensexplosion, 1980explosion, 1980

Same view,Same view,20 years later20 years later

II.II. Ecological Ecological SuccessionSuccession

- the replacement of one community by another over time

- one community changes the physical environment so that it can't survive but another community can

A.A. Primary Succession:Primary Succession:- succession on land that has

not been previously occupied- ex. lava, ash, bare rock- Pioneer species: mosses,

lichen - build soil

Primary Primary SuccessionSuccession

Succession in a Succession in a PondPond(a)(a)

(b)(b)

(c)(c)

B. Secondary B. Secondary SuccessionSuccession- reestablishing an ecosystem

following disturbance- ex. mudslides, hurricanes,

flood, ‘cool’ fire, clearcutting, abandoned fields

Secondary Secondary SuccessionSuccession

C. Climax EcosystemC. Climax Ecosystem- a stable,

balanced community

C. Climax EcosystemC. Climax Ecosystem- occurs at the end of

succession- can regenerate itself

(plants can tolerate shade)

III.III. Biomes:Biomes:- a large group of ecosystems

with a characteristic climate and dominant plant life

A. Aquatic BiomesA. Aquatic Biomes- supports great variety of life- limiting factors: light, oxygen,

CO2, nutrients, temperature

1.1. Marine Biomes:Marine Biomes:- vast and varied habitats- light penetrates only 100 -

600 feet (photic zone)

MarinMarinee

BiomeBiomess

Photic Photic ZoneZone

Aphotic Aphotic ZoneZone

Intertidal Intertidal ZoneZone

Neritic Neritic ZoneZone

Open Open Ocean Ocean ZoneZone

Deep-Deep-Sea Sea

ZoneZone

a)a) Intertidal Zone:Intertidal Zone:- harsh

environment: tides, waves, exposure to air

b)b) Neritic Zone:Neritic Zone:- between low tide and open-sea- abundant nutrients- most productive marine environment

Kelp ForestKelp ForestCoral ReefCoral Reef

c)c) Open-Ocean Zone:Open-Ocean Zone:- low nutrients and fewer

living organisms

d)d) Benthic Zone:Benthic Zone:- extremely

harsh environment

- cold, dark, high pressure

‘Black Smoker’

‘Black Smoker’

d)d) Benthic Zone: Benthic Zone:- habitat for bizarre fish and

other animalsFangtoothFangtooth

Deep-sea AnglerfishDeep-sea Anglerfish

UmbrellamouthGulper

UmbrellamouthGulper

2.2. Estuaries:Estuaries:- boundary between fresh

and salt water

2.2. Estuaries:Estuaries:

- highly productive habitat for many animals

- abundant nutrients and light- "nursery" for many animals

- boundary between fresh and salt water

3.3. Freshwater Biomes:Freshwater Biomes:- rivers, lakes,

ponds, and groundwater

- < 1% of earth's water

- drinking water- dumping

ground for wastes

B.B. Terrestrial BiomesTerrestrial Biomes- most important limiting

factors are temperature and precipitation

Terrestrial BiomesTerrestrial Biomes

High

High

( (Temperature)

Temperature) Low

Low

High

High

( (Temperature)

Temperature) Low

Low

DryDry (Rainfall) (Rainfall) WetWetDryDry (Rainfall) (Rainfall) WetWet

Climate Affects Biome Climate Affects Biome DistributionDistribution

Effects of Elevation on Effects of Elevation on TemperatureTemperature

Low

Low (

( Altitude)

Altitude)

High

High

Low

Low (

( Altitude)

Altitude)

High

High

EquatorialEquatorial (Latitude) (Latitude) PolarPolarEquatorialEquatorial (Latitude) (Latitude) PolarPolar

Olympic/Cascade Rain Olympic/Cascade Rain ShadowShadow

WestWest EastEast

100100

5050

00

50005000

40004000

30003000

20002000

10001000

00

Average AnnualAverage AnnualPrecipitation (cm)Precipitation (cm)

Altitude (m)Altitude (m)

150150

Earth’s Curvature Earth’s Curvature and Tilt Make and Tilt Make

SeasonsSeasonsShort days;

Long nights;Winter

Long days;Short nights;

Summer

Air Currents & Climatic Air Currents & Climatic RegionsRegionsSaharan & Arabian deserts are @ 30° N

South African Desertis @ 30° S

Congo rain forest is @ 0°

1.1. TundraTundra

TundraTundraTreeless region < 10 in. rain annuallyPermanently frozen soil (permafrost)Very fragile, scars last for centuries

Tundra

Taiga

Deciduous Forest

Grassland

Desert

Tropical Rain Forest

TreelessShort Plants

Very cold/ Brief summer< 10” Precip. / Permafrost

BiomeBiome ClimateClimate Dominant Dominant PlantsPlants

2.2. TaigaTaiga

TaigaTaiga(Northern Coniferous (Northern Coniferous

Forest)Forest)Northern Canada and Eurasia

Winters long & cold

Evergreen coniferous trees with needle-like leaves

Plant & animal diversity low

Tundra Very cold/ Brief summerTreeless< 10” Precip. / Permafrost Short

PlantsTaiga

Deciduous Forest

Grassland

Desert

Tropical Rain Forest

Conifers(Spruce/Fir)

Long winter/Short SummerLow Precip.

BiomeBiome ClimateClimate Dominant Dominant PlantsPlants

3.3. Temperate Deciduous Temperate Deciduous ForestsForests

Temperate Deciduous Temperate Deciduous ForestForest30-60 in. rain

annually, most during summer

Mostly deciduous trees, bare in winter

Leaf litter on soil

High diversity of animals

Tundra Very cold/ Brief summer Treeless< 10” Precip. / Permafrost Short Plants

Taiga Long winter/Short SummerConifersLow Precip. (Spruce/Fir)

Deciduous Forest

Grassland

Desert

Tropical Rain Forest

Deciduous Trees(Oak, Maple, Elm)

Cold winter/Warm summer30 - 60” Precip.

BiomeBiome ClimateClimate Dominant Dominant PlantsPlants

Temperate Rain Temperate Rain ForestForest

Temperate Rain ForestTemperate Rain ForestAbundant rain

Soil seldom freezes

Usually coastal

4.4. GrasslandsGrasslands

GrasslandGrasslandss10-30 in. rain/year

Usually in centers of continents

No trees except by rivers

Periodic droughts

Frequent fires

Most fertile soil in world

Overgrazing problems

Shortgrass PrairieShortgrass Prairie

Sagebrush Desert orShortgrass Prairie

Sagebrush Desert orShortgrass Prairie

Tundra Very cold/ Brief summer Treeless< 10” Precip. / Permafrost Short Plants

Taiga Long winter/Short summer ConifersLow Precip. (Spruce/Fir)

DeciduousCold winter/Warm summer Deciduous

Trees Forest 30 - 60” Precip. (Oak, Maple, Elm)

Grassland

Desert

Tropical Rain Forest

Grasses, GrainsTall wildflowers

Cold Winter/Warm Summer10 - 30” Precip.

BiomeBiome ClimateClimate Dominant Dominant PlantsPlants

5.5. DesertsDeserts

DesertDesertUsually found between 20-30° N & S latitude

Less than 10 in. rain/yr.

Boom & bust population growth after rain

Very fragile ecology

Tundra Very cold/ Brief summer Treeless< 10” Precip. / Permafrost Short Plants

Taiga Long winter/Short summer ConifersLow Precip. (Spruce/Fir)

Deciduous Cold winter/Warm summer Deciduous Trees Forest 30 - 60” Precip. (Oak, Maple, Elm)

Grassland Cold Winter/Warm Summer Grasses, Grains10 - 30” Precip. Tall wildflowers

Desert

Tropical Rain Forest

Sparse Veget.(Cactus, etc.)

BiomeBiome ClimateClimate Dominant Dominant PlantsPlants

Cold Winter/Hot summer< 10” Precip.

Sonoran DesertSonoran DesertArizona

Flowers indicate recent rain

Saguaro cactus unique to this desert

Environment Molds Physical Environment Molds Physical TraitsTraits

An AmericanAn Americancactuscactus

An AfricanAn Africaneuphorbeuphorb

ChaparralChaparral

The Chaparral BiomeThe Chaparral BiomeOften in coastal regions bordering deserts

Up to 30 in. rain annually, but all during cool months

Summers hot & dry

Small trees & large bushes

6.6. Tropical Rain Tropical Rain ForestForest

Tropical Rain Forest Tropical Rain Forest BiomeBiomeTemp 77-86 °F

Rainfall 100-160 inBiodiversity: 50-67% of all Earth’s species6% of land area40% now gone- Losing 70 acres/min> 25000 species go

extinct annuallyDominated by large, broadleaf, evergreen, complex forests

Complex, Evergreen, Broadleaf Forests

Tundra Very cold/ Brief summer Treeless< 10” Precip. / Permafrost Short Plants

Taiga Long winter/Short summer ConifersLow Precip. (Spruce/Fir)

Deciduous Cold winter/Warm summer Deciduous Trees Forest 30 - 60” Precip. (Oak, Maple, Elm)

Grassland Cold Winter/Warm Summer Grasses, Grains10 - 30” Precip. Tall wildflowers

Desert Cold Winter/Hot summer Sparse Veget.< 10” Precip. Cactus, etc.

Tropical Rain Forest

No winter

BiomeBiome ClimateClimate Dominant Dominant PlantsPlants

Tropical Deciduous Tropical Deciduous ForestForest

SavannaSavanna

The African SavannaThe African SavannaGrasses dominate; scattered trees Short rainy season

<12 in. (30 cm)/year

Long, severe droughts

African savanna with many large animals

Many species in danger of extinction

Ecosystem Productivity Ecosystem Productivity ComparedCompared(Grams of biomass/meter(Grams of biomass/meter22/year)/year)

OpenOpenOceanOcean(125)(125)

NeriticNeritic(360)(360)EstuaryEstuary

(1500)(1500)

TropicalTropicalRainforestRainforest

(2200)(2200)

TundraTundra(140)(140)

TaigaTaiga(800)(800)

TemperateTemperateDeciduous ForestDeciduous Forest

(1200)(1200)

GrasslandGrassland(600)(600)

DesertDesert(90)(90)

The The

EndEnd