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138 Cards in this Set

  • Front
  • Back
The biotic community & its abiotic enviro functioning as a system

{2 components=
Earth's Interception of Solar Radiation
Earth intercepts solar energy in *shortway radiation* (from hot masses=sun).
energy passes through atmosphere, then hits surface and is emitted back as *longwave radiation* (from cooler masses=earth).
Longer wavelengths can't pass through atmosphere as easily so some is returned to Earth.
==The Greenhouse Effect==
...crucial to maintaining surface temp of earth...
Temp Gradiant from Equator to Poles
the amount of solar radiation intercepted decreased with latitude away from equator.
*due to earth's tilt*
at higher latitudes radiation hits surface at steeper angle and has to travel through a deeper layer of air

&Reason for the Seasons = Earth's Tilt
(causes parts of earth to receive seasonal differences in solar radiation)
Air Temperature & Altitude
Air temperature decreases w/ altitude bc:
1)Decline in warming effect @ surface
-when longwave radiation is emitted from surface it heats air above it...
as air continues to rise decreasing pressure causes it to expand & cool
{*Adiabatic Cooling*}

2)increase altitude=decrease air density=fewer collisions of air molecules=less heat

***Increase in altitude = decrease in air pressure/atmospheric pressure (due to less air above us) AND decrease in air density***
Adiabatic Cooling
Decrease in air temperature through expansion---not heat loss

*responsible for decrease in temp w/altitude*
*ALSO moist air cools slower than dry air
Atmospheric Circulation
air=constant state of movement
due to vertical movements of air patterns & earth's rotation

air/H20 currents deflected rt in N Hemisphere
currents deflected lft in S Hemisphere

*3 Cells in each hemisphere
Vertical movements of air
(imaginary non-rotating earth)
-Equatorial region receives most solar radiation
-warm air rises bc its less dense than cooler air
-warm air from equator rises
=low pressure at surface
=air rising beneath it forces air mass to spread N & S
=as move toward poles air cools & sinks
==raises surface pressure
====that heavier air then moves back toward equator
Patterns in Ocean Currents
caused by
1)global pattern of wind
2)Coriolis Effet

*act like wind until hit continents

(Gyres go west (due2wind) til hit continents then split to N & S then cool, move east(due2wind), hit continents, then flow back to equator)
the 2 circular water motions that dominate each ocean

-N Hemisphere = clockwise
-S Hemisphere = counter clockwise
Atmospheric Moisture
expressed in relative humidity (percent of water in the air of the max amt of water the air could hold @ that temp)
Saturation Vapor Pressure
Max amt of moisture the air can hold at a given temp
Precipitation patterns determined by
Ocean Currents
Latent Heat
Amount of energy released or absorbed during change in state (of matter)

-more ordered (liquid) to less ordered (gas) state =energy is absorbed

-less ordered to more ordered =energy is released
Evaporation= liquid to gas state

Condensation= water vapor to liquid state
Rate of Evaporation = Rate of Condensation
The air is saturated

(when air & liquid h20 meet = molecules freely exchanged)
Non-random Spatial Distribution

*due to limits in distribution of organisms (no limits = no patterns)
group of individuals of the same species in an area--Interbreeding
all populations of different species living and interacting within an ecosystem
(in community terms)
Communities + Physical Enviro = Ecosystems
*exchanges of materials & flow of energy
(abiotic + biotic)

-adjacent ecosystems interact
a "Patchwork" pattern of adjacent ecosystems

(ecosystems linked by H20 flow & movement of organisms)
Basic Unit of Ecology?

-responds to enviro
-B & D = pop dynamics
-interactions = communities
-passes genes to next generations = nat. sel.
Why are there limits to distribution?
bc limits to information, genectic know-how

(Life Organized with Information)
Ecology of Single Species Population

(like studying certain aspects of gerbils)

("species one at a time")
*population ecology, psysiological ecology, life histories*
Ecology of plural species considered together

*wildlife ecology, communtiy ecology, landscape ecology, life zone ecology..*
Population Distribution described by 2 basic laws:
1) Lieberg's Law of the Minimum
-how much will a bucket hold?
2)Shelford's Law of Tolerance
-thought lieberg's was too simple--you can have too much of a good thing.
(middle--optimum is better than min and max)
Shelford's laws of distribution
(law of tolerance)
1)the range of a species is limited by changes in limiting factors (factors beyond limit tolerated by the species)
2)the distribution area (where species can live) is determined by the power of migration & their tolerance

**they live there bc they can stand it & they can get there
Gradiant Analysis
plot of
Species Distribution against a Spatial Vaiable
(elevation, temp, moisture, nutrients)

AKA: relative abundance of individuals of a species along enviro gradiants


{shows communities are generalizations...not absolute}
Zonation v Succesion
-changes in community structure across landscape

-changes in community structure through time
Primary Succession
on Newly Exposed Surface (NO SOIL)

ex. st helens, glacier bay
Secondary Succession
vegetation has been removed but SOIL REMAINS
(after disturbances)

ex. post fire
Changes over succession?
Species presence & Relative abundance
150 year study of succesion?
identify differences in space
which represent
differences in time

(old field succession- when was the field abandoned?)
Trends in Ecological Succesion

(from Early to Late)
-food webs->more complex
-nutrient cycling->tighter
-photosynthetic/respiration (P/R Ratio)->lowers from >1 to ~1
Ecological Succesion
change in composition of biotic community over "ecological time" (10-1000 yrs)

ex. abandoned field= weeds->herbs->shrubs
*can be cyclical (fire-prone ecosystems)
Community Evolution
development of regional biota over "evolutionary time" (1000-1000000 yrs)

ex. savannas replaced by grassland as rockies rise & rainshadow forms
Physiological time
Ecological time
Evolutionary time
Why does ecological Succession occur?

2 competing (prob both right) theories
-early species (pioneers) change the conditions of a site to make it more habitable for later invading species

-early species resist invasion & remain until they're replaced by:
Competition, Predation, Disturbance
theory of ecological succession
early species (pioneers) change the conditions of a site to make it more habitable for later invading species
theory of ecological succession
early species resist invasion & remain until they're replaced by:
Competition, Predation, Disturbance
Natural Selection Requires (2)
1)Variation among individuals
2)differences in survival and reproduction (fitness)
contribution individual makes to future generations
trait shifted to one extreme or the other

Favors both extremes simultaniously

favors individuals near mean population
1)alternate units control heritable traits
2)for each characteristic organism has 2 units
3)when 2 units are different the dominant is expressed & recessive is not

(unit = gene/allele)-later
DNA's contained in
(which are oganized into subunits--GENES)
alternate forms of genes =
water cycle
solar radiation provides energy for evaporation of water

2-interception (some water doesn't infiltrate into ground and evaporates back into air
3-filtration (leads to groundwater)
4-Evapotranspiration (sum of evaporating water from surface and from transpiration {the evaporation of water from leaves/plants}
Water's physical Properties
*H+ O- bonding*
a)hydrogen bonding
b)high specific heat
c)cohesion & surface tension
e)high solubility
Specific Heat of Water
large quantities of heat energy required to change state of matter

bc of lattice arrangement of H & O water becomes denser til 4* C then decreases in density

*Ice floats bc lattice structure has holes=not dense
-insulates water below
Cohesion & Surface Tension
water molecules stick to eachother resisting breaking

Surface Tension-
water hits air=weaker attraction than water to water below
Viscosity of water
due to cohesion (attraction of water molecules = harder to seperate)

viscosity of water is much greater than air
-also due to fact that its more dense than air
----causes buoyancy
caused by viscosity

if body's weight in water is is less than water it displaces = upward force = buoyancy
*since most aquatic animals have nuetral buoyancy they don't require structural material (skeletons) to hold themselves erect in water

*ps. higher density of water means greater changes in pressure than in air
Water as a Solvent
boundery between air and H20 experiences DIFFUSION (molecules move from high concentration to low concentration)

= net transfer of Oxygen &Carbon Dioxide
Solubility in water depends on
-solubility decreases at temperature increases (solubility greater at lower temps)
(solubility increases as pressure increases)
(solubility decreases as salinity increases)

*greater density and viscocity of water limit diffusion from air
Solubility of O2 and CO2 (carbon dioxide)
-solubility of O2= low
-solubility of CO2= high
-CO2 reacts w/H20 and produces carbonic acid
--->result in more H+
--->more acidity (more H+ = more acidic)

*alkaline = more OH- less H+
Light & Water
lower angle light hits = more reflected

light in water reduced by:
-water itself absorbs light
Water & Temperature
*high heat capacity *resists change in temp
*high heat of vaporization
*high heat of fusion (energy taken out to freeze

-surface temperatures = reflect incoming/outgoing radiation
-decline in solar radiation w/depth
-most rapid decline = thermocline

*thermocline seperates warm upper "epilimnion" and deeper colder denser "hypolimnion"
Standing bodies of water Circulation in spring/fall
temp & sunlight low
-surface water cools
-becomes denser & sinks
-warmer water goes to surface
-it cools and sinks
=vertical circulation

ps. in winter warmest part is at bottom
Water as a Solvent (in general)

*solution w/H20 as solvent = acqueous solution
-can dissolve more substances than any liquid
-nutrients and waste are dissolved and transported
-solubility due to H-bonding (attract molecules carrying a charge)
--->ex. sodium chloride (Na+) & (Cl-) are more attracted to water molecules than eachother.... so they dissasociate and dissolve
(solubility of sodium chloride =HIGH)

*when concentration reaches solute max excess amts are deposited as sediments
water distribution

*highest to lowest*
**Hydrosphere crucial to biosphere but biosphere trivial to hydrosphere
first law of ecology
water flows downhill
--integrates ecosystems (connects landscapes)
Simplest measure of Community Structure
Species Richness
number of species w/i a community
Spatial Patterns
-species distributions/limits
-productivity (primary & secondary)
-Biotic Communities
Time Patterns
-individual position/movement
-population dynamics
-ecological succession
-community development
(community evolution)
patchwork or different types of land
(all in an ecological community)
*product of boundaries defined by changes in structure of distinct patches
-distinct LOCAL communities
-realatively homogeneous
-differ from surroundings in structure and species comp
-embedded in matrix
-produced by variations in geology(rocks), topography(physical structure), soil, climate, human activity, natural events (fire, grazing)

*crop fields, forests, ponds*
Landscape Ecology
study of causes of formation of patches and boundaries (and the consequences of these spatial patterns--concerned w/size/shape of patches)

[the interactions depend on size and spatial arrangement]

(think of ecosphere as hierarchy)

*landscapes dynamic in space and time (change occurs)
*complexity is key
group of many different patches
area, shape, & orientation
-their suitability as habitats
-influence ecological processes (wind flow, seed dispersal, animal movement)
physical structure of a landscape
the perimeter of a patch
Inherent Edges
-abrupt change in physical conditions (topography, substrate, soil type, microclimate)BETWEEN COMMUNITIES (patches)

-long term natural features (like rock outcrops)
-usually stable & Permanent
Induced Edges
-resulting from natural disturbances (fires storms floods) & human activity (housing, farms)

-edges that are subject to successional changes over time
where edge of one patch meets edge of another

(area of contact, seperation, transition between patches)
Wide Borders form transition zone called
Edge Species
species restricted exclusively to edge environments
Edge Effect
high species richness bc they can support species of adjoining communities & opportunistic species adapt to edges

influenced by
-border area available
-greater contrast between patches= greater diversity
strips of similar habitat
-connect seperate patches
-usually of human origin
-provide habitat
-can act as filters/barriers
-permit travel ways
Filter effect
gaps in corridors allow some organisms to cross and restrict others
-can spread diseases between patches
(can be roads)
event that disrupts community structure & function
-create patterns & are influenced by patterns

*Intensity= measured by proportion of total pop that disturbance kills
*Scale= the spatial extent of impact relative to size of affected landscape
*Frequency= mean # of disturbances in a time interval
Small Scale
Large Scale
-make gaps
-creating patches of different comp. and stage

-favor opportunistic species
-species like original pop eventually replace early species

SEVERE disturbances:
can replace a community altogether

*too frequent disturbances can eliminate a species
"Shifting Mosaic"
the patches of communities that define a landscape is always changing

-landscape is composed of patches each in different stages of development
patchwork mosaics
Biological Molecules
and their monomers
*Fats-->Fatty Acids & Glycerol
*Proteins-->Amino Acids
*Nucleic Acids-->Nucleotides
Dominant Species
species predominating community
-based on # and size of individuals
Keystone SPecies
have influence on community disproportionate to their #s

-removal causes changes in structure and significant loss of diversity
Basal Species
feed on no other species but are fed upon by others
Intermediate species
feed on other species and are also prey of other species
Top Predators
prey on intermediate and basal species
and aren't fed on by other species
spatial change in community structure
groups of species that exploit a common resource in a similar fashion

(ex. hummingbirds & other nectar feeding birds exploit flowering plants)
Functional Type
group of species based on common response to environment, life history, or role in community
2 views of community
1)Organismic Concept of Communities
-community as unit - each species component of the whole
-whenever a habitat repeats the same species occurs
-species in association have similar distributional limits
-common evolutionary history & similar tolerances

2)Individualistic/Continuum Concept
-relationship among species in a community are a result of their tolerances --NOT strong interactions or common evolutionary history
Ecology v
Environmental Management v
science of understanding our surroundings

how CAN we work the world

how SHOULD we work the world (lifestyle choices)
Modes of Evolution
(different time scales)

Shortest to Longest
Origin of Life

Extraterrestrial Hypo
"seeds" from space arrived on meteorites
Origin of Life

Chemoautotrophic Hypo
life from the deep
-from deep sea hydrothermal vents
Mechanism of Organic Evolution
Natural Selection
Darwin Observed (3)
(more offspring produced than survive to reproduce)
(struggle for resources in finite enviros)

CONCLUSION: natural selection

(2/3 ecology[overpop & competition], 1/3 genetics [variation])
Darwin didn't understand
-mechanisms of genetics
Fundamental Forces of Nature:
*fundamental force of life

-Weakest to Strongest-
Fragmentation can occur on what scale
any spatial scale
-from roads to continental drift
-bigger than states, smaller than continents
-distinguished by vegetation & climate
-emphasize evolutionary convergence & -paralled evolution (dissimilar organisms come to look similar *placental & marsupial animals*

*biomes regional community, life zones local community*
2 types of environmental change
1)autogenic - result of organisms in community
2) allogenic - of physical enviro (temp)
Riparian Corridors
woodland along bank of river
The most abundant elements in earth's crust are:
Fathers of Ecology:
Leeward side of mountain =
rain shadow
Life zones driven by


(life zones more useful in steep gradiants bc H20 flows downhill)
standing water zoned by :
2)production/respiration (P/R Ratio)
6 Major Elements in Organic Molecules
H -hydrogen
O -oxygen
C -carbon
N -nitrogen
P -phosphorous
S -sulfur

Land : H20 =
1 : 3
Gas Content
1/4 Oxygen
3/4 Nitrogen
Efficiency of Energy Transfers

(100- plant =
10- 1* consumer =
1- 2* consumer)

Humans are expensive for biosphere to maintain bc
-warm (endothermic)
-consumers (herbivores, carnivores, omnivores)
ecosystem ecology
study of whole living systems
phsiological ecology
responses of individuals to environmental conditions
(temp, moisture, light)
The Grants'
documented natural selection (& the different types) on galapagos islands after darwin
Gene Pool
Chromosomes(contain DNA)
Genes(subunit on chrom that carries DNA)
Alleles(alternate forms of a gene)
Locus(where allele occupies chrom)
Homozygous(allels on locus are the same)
Heterozygous(alleles are different)
Genotype(sum of hereditary info)
Phenotype(external expression of genotype)
Gene Pool(total collection of genes in all individuals of a pop)
Hardy-Weinberg Principle
gene frequencies will remain the same over time IF

1)mating is random
2)mutations don't occur
3)pop is large
4)natural selection doesn't occur
5)migrations don't occur
Biological Species
a group of populations whose individuals have the potential to interbreed
isolating mechanisms
allow a species to remain distinct
-reproductive barriers --don't allow exchange of genes between populations

--premating (habitat, isolation, behavior, mechanical)
--postmating (reduce reproductive success of offspring that arise from mating of ind of diff species)
offspring resulting from mating of 2 diff species
Sympatric species
occupy the same area at the same time -- opportunity to interbreed
Allopatric Species
occupy areas seperated by time or space (don't come into physical contact with eachother)
high temps lethal to most organisms bc
they denature proteins
life zones
NOT the same as biomes

*are influenced by temperature
international biological program in the US (US-IBP)
efforts organized by biomes
life zones
conservation ecology & population ecology...
go hand in hand
brought engeneering perspective to ecological energetics
science is:
-a search for patterns of cause and effect in the universe

-common sense--natural way of working the human mind

-an evolution tested process
an african plant is similar in appearance to a mexican plant
convergent evolution

(development of similar characteristics of species in different areas but under similar enviro conditions)
organic evolution
*change in gene frequency over time

[central concept in ecology]
based on lecture
scientific study of ecology in colorado began with
paleolithic people ~15,000 yrs ago
biological magnification
accumulation of fat-soluble chemicals thru food chain

(pesticides etc)
communication necessarily involves
1)sending individual (or cell)

2)receiving individual (or cell)

3) irritability (biological sense of word)
larger edge per area

advantage of who?

(in support of several small argument)
people involved in laying foundations for conservation ecology
(mathematical ecologist)

-e.o. wilson

(pioneer evolutionist)

(community ecologist)