Announcements Kevin and I will hold office hours together today in Girvetz 2307 Kevin and I will...

AnnouncementsAnnouncements

• Kevin and I will hold office hours Kevin and I will hold office hours together today in Girvetz 2307together today in Girvetz 2307

• Michael Pollan article to read for Michael Pollan article to read for section this weeksection this week

Summary from FridaySummary from Friday

• Definition of soilDefinition of soil• Soil developmentSoil development

• additions, losses, transformations, and additions, losses, transformations, and translocationstranslocations

• Classification of soilClassification of soil• 12 different orders12 different orders

• Factors of soil formation: Factors of soil formation: Cl.O.R.P.T.H.Cl.O.R.P.T.H.• BiomesBiomes

• function of temperature and moisturefunction of temperature and moisture

Two-Minute QuizTwo-Minute QuizDuring your spring break you decide to During your spring break you decide to take a road trip through 18 states in 7 take a road trip through 18 states in 7 days. Early one morning in the middle days. Early one morning in the middle of the week you wake up and realize of the week you wake up and realize that you can’t remember where you that you can’t remember where you are.are.

You step outside to investigate your You step outside to investigate your surroundings, and notice a lovely road surroundings, and notice a lovely road cut where the soil profile is visible from cut where the soil profile is visible from “O” horizon to bedrock.“O” horizon to bedrock.

Here are your Here are your observations:observations:

• The soil is dark red and The soil is dark red and clayey.clayey.

• The profile is deep.The profile is deep.• There are rolling hills, There are rolling hills,

but no sharp peaks in but no sharp peaks in the distancethe distance

• The temperature is 65° The temperature is 65° F.F.

• The air is humid, and The air is humid, and the vegetation is lush. the vegetation is lush.

Where are you?Where are you?

a)a) upstate New Yorkupstate New York

b)b) near Ames, Iowanear Ames, Iowa

c)c) down a backcountry road in Georgiadown a backcountry road in Georgia

d)d) along the coast of Mainealong the coast of Maine

e)e) near the border of New Mexico in near the border of New Mexico in ArizonaArizona

Biome:

A large climatic region where plants are similar to each other

What is missing?

Arctic Tundra:

Short growing season

Intense cold

Strong winds

Permafrost

Low primary productivity

Slow decomposition

Boreal forest: Cold winters, warm summers

Cone-shaped trees- shed snow

- catch light

Peatlands- slow decomposition

Fire

Temperate forest: Evergreen and deciduous

Intermediate temperature

Adequate moisture

Few constraints on growth

High primary

productivity

Grasslands: Continental regions

- hot summer, low rainfall

Fires

Grazing

Deserts: North and south of tropics

Dry

Hot or cold

Organisms have adapted

to this environment

Plant adaptation to hot environments:

Physical Structure

Plant adaptations: Plant adaptations: PhysiologyPhysiology

• Stomata must be open to take in COStomata must be open to take in CO22

• Open stomata = water lossOpen stomata = water loss• How can a plant minimize water loss?How can a plant minimize water loss?

• Keep stomata closed as much as possibleKeep stomata closed as much as possible• Open only at night = CAM plantsOpen only at night = CAM plants

• Cactus, some epiphytes, succulentsCactus, some epiphytes, succulents

• Open only a little bit = COpen only a little bit = C44 plants plants• Some grassesSome grasses

Which grasslands are likely to be C4?

Tropical Rainforests

Tropical rainforests: Near the equator

Hot

Moist conditions

Tight cycling of nutrients- soils are actually quite poor

High primary productivity

Fast decomposition

Where is Santa Barbara?

Chaparral or Mediterranean-Chaparral or Mediterranean-typetype

• Strong seasonality Strong seasonality • Hot, dry summersHot, dry summers• Mild, wet winters Mild, wet winters high productivity high productivity

• Fires feed on large fuel supplyFires feed on large fuel supply

AnnouncementsAnnouncements

• I will be gone on Friday – Theresa and I will be gone on Friday – Theresa and Kevin will be giving presentationsKevin will be giving presentations

• Read the Michael Pollan article for Read the Michael Pollan article for section. It is now available online too. section. It is now available online too.

Summary from MondaySummary from Monday

• Biome= climatic region where the Biome= climatic region where the vegetation is similarvegetation is similar

• Hadley CellsHadley Cells• Terrestrial BiomesTerrestrial Biomes

• Arctic TundraArctic Tundra• Boreal ForestBoreal Forest• Temperate ForestTemperate Forest• GrasslandGrassland• Desert- Desert- physical and physiological adaptations of physical and physiological adaptations of

plantsplants• Tropical RainforestTropical Rainforest• Mediterranean/ChaparralMediterranean/Chaparral

What is missing?

Aquatic EcosystemsAquatic Ecosystems

• Streams and RiversStreams and Rivers• LakesLakes• EstuariesEstuaries• Freshwater wetlandsFreshwater wetlands• OceansOceans

Streams and RiversStreams and Rivers

Streams and RiversStreams and Rivers

5th order

4th order

3rd order

2nd order

1st order (headwaters

)

How do large and small streams How do large and small streams differ?differ?

• Low stream order (i.e., 1Low stream order (i.e., 1stst or 2 or 2ndnd order) order)• Small, narrow, shallowSmall, narrow, shallow• Steep, fast-flowing rocky bottomSteep, fast-flowing rocky bottom• Detritivore community breaks down litterDetritivore community breaks down litter

• High stream order (i.e., 4High stream order (i.e., 4thth or 5 or 5thth order) order)• Big, wide, deepBig, wide, deep• Shallow slope, slow flowingShallow slope, slow flowing• Processed litter comes from upstreamProcessed litter comes from upstream

Production vs. Biomass Production vs. Biomass PyramidsPyramids

Primary Producers

Herbivores

Carnivores

Production vs. Biomass Production vs. Biomass PyramidsPyramids

Primary Producers

Herbivores

Carnivores

Standing Biomass

Primary Producers

Herbivores

Carnivores

Productivity

Production vs. Biomass Production vs. Biomass PyramidsPyramids

Primary Producers

Herbivores

Carnivores

Standing Biomass

Primary Producers

Herbivores

Carnivores

Productivity

How do these pyramids differ in terrestrial vs. aquatic ecosystems?

Light Penetration in LakesLight Penetration in Lakes

Secchi disk

Euphotic zone

Aphotic zone

Sediment

eu: well or good a:

without

Thermal Stratification of Thermal Stratification of LakesLakes

Epilimnion

HypolimnionSediment

Summer

Thermocline

Thermal Stratification of Thermal Stratification of LakesLakes

Epilimnion

Hypolimnion

Thermocline Sediment

Epilimnion

HypolimnionSediment

(wind)

Summer Fall

Thermal Stratification of Thermal Stratification of LakesLakes

Epilimnion

Hypolimnion

Thermocline Sediment

Well-mixed profileSediment

Epilimnion

HypolimnionSediment

(wind)

Summer Fall

Winter

Thermal Stratification of Thermal Stratification of LakesLakes

Epilimnion

Hypolimnion

Thermocline Sediment

Well-mixed profileSediment

Well-mixed profileSediment

Epilimnion

HypolimnionSediment

(wind)

Summer Fall

WinterSpring

Thermal Stratification and Thermal Stratification and OxygenOxygen

Well-mixed profile

Sediment

Epilimnion

Hypolimnion

Sediment

Summer

Winter

Phytoplankton and abiotic factors in a lake

Oligotrophic vs. Eutrophic Lakes

Wetlands: where water meets Wetlands: where water meets landland

All wetlands are All wetlands are ecotonesecotones

• Salt marshes: costal, brackishSalt marshes: costal, brackish• Swamps: wooded, fresh waterSwamps: wooded, fresh water• Fens: external water and nutrient Fens: external water and nutrient

inputsinputs• dominated by sedgesdominated by sedges

• Bogs: little external nutrient input Bogs: little external nutrient input • dominated by sphagnum mossdominated by sphagnum moss

Wetland Biogeochemistry

• When land is flooded, OWhen land is flooded, O22 gets used up by gets used up by decomposers and the soil becomes decomposers and the soil becomes anaerobicanaerobic

Wetland BiogeochemistryWetland Biogeochemistry

• When land is flooded, OWhen land is flooded, O22 gets used up by gets used up by decomposers and the soil becomes decomposers and the soil becomes anaerobicanaerobic

• Demand for ODemand for O22 is still high is still high

Wetland BiogeochemistryWetland Biogeochemistry

• When land is flooded, OWhen land is flooded, O22 gets used up by gets used up by decomposers and the soil becomes decomposers and the soil becomes anaerobicanaerobic

• Demand for ODemand for O22 is still high is still high• Other minerals containing oxygen get Other minerals containing oxygen get

reducedreduced

Wetland BiogeochemistryWetland Biogeochemistry

• When land is flooded, OWhen land is flooded, O22 gets used up by gets used up by decomposers and the soil becomes decomposers and the soil becomes anaerobicanaerobic

• Demand for ODemand for O22 is still high is still high• Other minerals containing oxygen get Other minerals containing oxygen get

reducedreduced• Reduction is when a compound gains an Reduction is when a compound gains an

electron- in this case by giving up an Oelectron- in this case by giving up an O22 atom atom

• Some molecules release OSome molecules release O22 more easily than more easily than othersothers

Wetland BiogeochemistryWetland Biogeochemistry

O2 NO3- Fe(OH)3 MnO2 SO4

2- CO2

• When land is flooded, OWhen land is flooded, O22 gets used up by gets used up by decomposers and the soil becomes decomposers and the soil becomes anaerobicanaerobic

• Demand for ODemand for O22 is still high is still high• Other minerals containing oxygen get Other minerals containing oxygen get reducedreduced

• Reduction is when a compound gains an electron- in Reduction is when a compound gains an electron- in this case by giving up an Othis case by giving up an O22 atom atom

• Some molecules release OSome molecules release O22 more easily than others more easily than others

• If the water level drops, OIf the water level drops, O22 enters the soil again, enters the soil again, and the reduced substances can get and the reduced substances can get oxidizedoxidized

Wetland BiogeochemistryWetland Biogeochemistry

O2 NO3- Fe(OH)3 MnO2 SO4

2- CO2