Natural History 3

Natural History 3










Facts
o
o
o
o

about Earth
Earth rotates 24 hours
Age of earth is 4.567 billion years
Exists in a rotating galaxy known as the milky way
Earth races toward the star Vega
 Everything is rotating as you move
o 23.5 tilted axis
o First life 3.5 billion bp
o Dinosaurs
 231 million to 65 million bp
o Humans
 150,000 – 200,000 bp
o Last ice age ended 25, 000
Carbon Dioxide Concentration
o Increased since 1958 at various latitudes
o Why is this important?
 Carbon dioxide is a greenhouse gas
 Can trap long wave energy from the short wave sun rays
 Builds up energy and creates a warming effect
o This is why earth is not cold
o Climate change
 Suggested that the use of fossil fuels by humans has increased
CO2 and caused an even greater warming effect
o We can measure atmospheric activity by using ice cores, which has gas
pockets
Forest and CO2
o Forests take CO2 for growth, as do grasslands
Sun and Geomagnetic Storms
o Erupts on the sun throw out ions from storms
 Earth is protected by its magnetic core
Equator and Other
o Equator
 0 degrees
 Warmest and wettest area on earth
 Moist air will rise
 As it goes up it gets cold
 Cold air cannot hold much water
 Rainfall with occur
 Air will continue to rise and go north and west from the equator
 Deserts will occur at 30 degrees
 The air is dry and hot
o Holds onto little moisture tightly
o Adiabatic lapse rate
 Predictable cooling with altitude
Global Air Currents

o

0-30







30-60
 Westerlies
o Wind current
 In the north go clockwise
 Southern hemisphere
 Counterclockwise
 Due to the spin of the earth
Ocean Currents
o In the North
 Clockwise rotation
o South
 Counterclockwise
o Why is this important?
 Maritime Climates
 Climate determined by neighboring watered
 Caribbean water will flow to the eastern coast of the United
States
 Pacific water is cold because it comes from the north
Moon
o Stabilizes the tilt of the earth
Earth and its tilt
o Winter in the Northern hemisphere
 Caused by the oblique angle caused by the tilt
 No direct sunlight
 Southern has summer
 Direct sunlight in the south
o Particularly at 23.5 degrees south
o Tropic of Cancer
 23.5 North
o Tropic of Capricorn
 23.5 South
o






North and south of the equator
 Winds go east to west
Trade winds
 Ships depended on these constant winds to travel from
place to place
0 degrees
 Sometimes no wind
 Currents converge and go up at equator
 Tropical doldrums
 High pressure system
30 degrees
 Horse latitudes
o “throw livestock overboard”
 Wind comes down, not up, but is like the equator

Between these two points is known as the tropics
Earth tilting side ways
 Sun strikes at equator
 Equal sunlight in both hemisphere
 Equinoxes
 Spring and Autumn
Solstice
o Summer
 June 22
 Sun is at the tropic of cancer
o Winter Solstice
 December 22
 Sun is at the tropic of Capricorn
Inter-tropical convergence zone
o Where winds from the north and south meet at the equator
o Rainfall at the equator
 Autumn and spring when light is equal and hits at equator
 Shifts with the angle
o “Wet” season
 6 months of wet and 6 months of dry
 “monsoon”
 Savannahs benefit from this
o Shifts north in northern hemisphere summer
o Shifts south in southern hemisphere summer
Serengeti Plain
o Important eco system
 Has the highest diversity of hooved animals
 Known as Ungulates
Major deserts
o Sahara and Namib
o Occur at 30 degrees
Around the equator
o Rainforests
o Amazon
Soil
o Not “dirt”
o Soil is itself an ecosystem
Soil as an Ecosystem
o Has organic and mineral matter
o Takes a long time to form
 1,000 years to make one inch of top soil
Living Soil
o Mineralization
 Process of converting organic material into organic material
 Dead insects and plants can be broken down to minerals
by bacteria and fungi
 Humus
o
o























 Partially decomposed organic matter
Soil composition
o Anaerobic soils
 Soils with much organic matter, little oxygen
Effect of Climate on soil
o Mesic
 Produces perhaps the best soils
 Grasslands, prairie
 10 to 12 foot deep soils
o Wet
 Heavy leaching
 High clay content
Bed Rock
o Igneous
 Formed from the cooling of molten lava
 Granite/Basalt, both are components of crust
o Sedimentary
 Compacted sediments
Soil Formation
o Mechanical
o Chemical
 Organic acids that break down rock
o Climate can affect weathering
 Calcification
 Soil formation in hot, dry conditions
o Caliche
 Occurs on the top of this soil
 Salinization
 Occurs in areas high in salt
o Hot dry area, high in rainfall
 Salt is washed deep, but rises with water
evaporation
 Gleization
 Arctic tundra
 Permafrost
 Podsolization
 Occurs in mesic areas
o Temperate areas that get good rainfall
o Podzols are good soils for growing crops
 Laterization
 Tropics
 Hot temperatures and lots of rainfall
 Water leaches nutrients out of the soil
o Lots of iron, aluminum
Soils
o Caliche









 High in calcium
Soil Physical Characteristics
o Sand doesn’t hold water or nutrients
o Has a lot of oxygen because there is a lot of space
o Micelles
 Flat particles of clay that has the nutrients
o Best soil has roughly even amounts of all three types
 Loam soil
Plants and Soil conditions
o Some plants have evolved to grow in certain soils
 Havard Oak
 Grows in sand
 Roots are very long and deep, reach the water table
 Only find in completely sand soils
Roots
o Fibrous roots
 Fine, divided roots
 Grasses
 Advantages
 Anchoring
 Holding the topsoil down
 Take up water quickly
o Non-grasses
 Tap root
 Go down to the water table
 Food storage
o Tip of root
 Root cap
 Watery parenchyma cells
 New cells produced
 Region of maturation
 Cells that carry water and nutrients
 Production of root hairs
o Pick up nutrients from clay through ion exchange
Soil Moisture
o Field capacity
 Capacity of a soil to hold onto water
 pound of dry soil with screen
o Weight of soil vs weight of soil after draining water
through
o Free water
 Water that simply filters through
 “hard fast rain”
o Capillary
 Capillary action holds onto water
 Most important

Hygroscopic water
 Microscopic water molecules that cling very tightly
 Always there but never available
o Wilting Point
 Point at which a plant has wilted and cannot revive
 Plants are held rigid by water pressure
Micronutrients
o Used in very little quantity by plants, but still important: very specific
uses
o Copper
 Can be toxic in large amounts
 Needed because chloroplasts have a copper component
Macronutrients
o Used in relatively large quantities
Fire
o Has a special purpose in nature
o Natural fires can have positive effects
Fires
o Surface fires
 “cool” fire
 Coolest of the three
 Grasslands
 Have root and shoot at the top
 Fire essentially kills the leaves, but grass will continue to
grow with new nutrients
 Competitors are killed by fire
o Ground Fire
 Hot, slow burning fire
 Tundra
 Kills root systems
o Crown Fires
 Most destructive
 Very hot
 Can create a fire storm
 Can superheat trees and cause them to explode
 Can create fire tornado
Why fires?
o Burn up dead organic matter
 Releases nutrients
o Seed release
 Cones that will release seeds during fires
 No competition
 Warm, carbon dioxide rich soil
Fire disclimax
o Ecosystem is pine because of fires
Giant Redwood
o


























o Evolved to survive fires
o Foot thick bark
Water
o Organisms are mostly water
Specific heat
o Energy needed to raise the temperature of water
 Takes a relatively high amount
o Latent heat
 Energy need to move water from one state to another, also
relatively high
o Density
 Water is most dense at 4 degrees C
 Drops to the bottom
 If water was most dense at 0 C
o Ponds would freeze from the bottom up and kill all
the animals
o Buoyancy
 Ability of water to support something
Specific Heat
o Benefit
 When places are near water, the temperature is very moderate
 Water is hard to heat, so it keeps an area hard to change
temperature
 Keeps sea animals safe
Latent Heat
Density of Water
Cohesion
Viscosity
o In water bulbous front facilitates movement due to the viscosity
Buoyancy
o Species in the water do not need to spend much energy on support
 Water plants vs. land plants
 Trees need to spend a lot of energy on support
Koppen
o First scientist to make a map of the world in relation to climate
Biogeoraphical realms
o Large areas of the earth where plants and animals have evolved
together for years
 Laurasia
 Nearctic
 Palearctic
o Alfred Wallace
 Biogeographic realm classification
 Indiana Jones
 Recovered plants and other specimens




Neartic
 Diverse
 North America
o Endemic
 Species that occurs in one area only
o Marsupial mammals
 Primitive animals
Biomes
o Ecosystems around the world that have the same structure
 Grasslands
 Get the same amount of rain
 Have roughly the same amount of species
Climograph whitaker
o Maps annual precipitation against temperature
o





Ship fire caused him to lose most of his research, but he
made it back home
Went to new guinea and developed the idea of
biogeographical realms