I Biology I
Lecture Outline
References (Textbook -pages 818, 837-926)
Definitions
History
Levels of Study
1. Population Ecology
A.
Definition and Overview
B.
Examples of Population Ecology Studies
2. Community Ecology
A.
Definition and Overview
B. Examples of Community Ecology Studies
3. Ecosystem Ecology
A. Definition and Overview
B. Examples of Ecosystem Studies
4. The Biosphere
A.
Definition and Overview
B. Examples of Biosphere Studies
Ecology
I Biology I
Lecture Notes Ecology
References (Textbook -pages 818, 837-926)
Definitions
1. Your textbook defmes ecology as the study ojthe interactions ojorganisms with
other organisms and with the physical and chemical environment.
2. The word ecology is derived from the Greek word "oikos" that means house or
home.
3. In a simplistic way one could say ecology is the study of the house or home of Life on
earth.
4. Ecology is a basic division of the Science of Biology much like Botany and Zoology.
History
I. Anton van Leeuwenhoek a Dutch shopkeeper studied "jood chains" and "population
regulation" in the early 1700's.
l.uuw~lfhoek "JlSuaJJy rl!rtfOftlN!"-d ID lire ~fa1"er ofille microscope" .
probobly thefirst peT.WIf to ~ee ceIb wing /I microscope.
H~
built th~ first microscope and was
2. Ernst Baeckel, a German Biologists,jirst used the word ecology in 1866.
3. Ecology did not mature into a distinctfudd of study lUltil the early 1900's.
4. During the 1960's, ecology finally became part of the general public vocabulary and
a distinct curriculum at universities in the U.S. and elsewhere.
Levels of Study
(see handout of Table 46.1 Ecological Terms from page 438 oflatbook)
• One of the most common ways scientists approach the study of ecology is to
hreak it down into what are called "levels oforganization".
• We studied "levels oforganizahon" in a single animal and found the following
progression.
CELLS-TISSUES-ORGANS-ORGAN SYSTEMS- - - - ORGANISM
• We can continue the progression and do something similar for the study of
ecology.
ORGAN1SM-POPULATlON-COMMUN1TY-ECOSYSTEM- - - BIOSPHERE
• We will cover these levels using the titles
Population Ecology
Community Ecology
Ecosystem Ecology
The Biosphere
1. PopulationEcology
A. Definition and Overview
• Population Ecology is defined as the study ofa group oforganisms of
the same species occupying a certain geographic area and sharing a
common gene pooL
• Population is a word normally used to denote a group of people in a
given area.
(E:xImtpIn indutk lire population ofTTmlon, tire populaJion ofGiMon County, or
tire popuialion of TennLSUL)
• In ecology the word is used in a similar way.
B. Examples of Population Ecology Studies
• Population Densities.
(1) Whitetail Deer population estimates for TWRA's Hom Bluff
Wildlife Management Area
(2) Whitetail Deer population estimates for the State of Tennessee
• Population Growth Rates.
( 1) Depends on birth rates, death rates, emigration, and
immigration.
(2) Includes studies measuring increase or decrease in population
densities over time in a particular area
(3) For hypothetical example - a study that found that the human
population growth rate in Gibson County to be a 5% increase
each year from 1990 to 2000.
• DispersaJ Patterns.
( 1) Dispersal patterns represent how individuals of a species are
distributed across a geographic area.
(2) There are 3 basic dispersal patterns.
CLUMPED
.. ..
(DrawollblacA;board)
RANDOM
----~.~a~.~------7
.
,..
/_- - -,
•
0,· '
~. '
'1
D( -:U! ~ (. ( P ~
t-.
-1'"
fwr
-
le E.'
Id
Tzr
I ,"'" _::.
/
. _ ,"
~o
Zt(f ~ \ I\ ~ -
/
~
J
.::>
J
(}« l-t r .,. , {P!
i
fill f::: ~rq ,<t'
' f'
UNIFORM
•
Life History Studies.
(I) Example would be a Life History Study of the Bald Eagle that
answered such questions as
When do they mate? How long do they live? What do they eat? How many eggs does a female lay? Etc, Etc. 2. Community Ecology
A. Definition and Overview
• Community Ecology is defined as the studies ofan assemblage of
populations interacting with one another within the same
environment
• Assemblage of populations is a fancy wt9' of saying a group of
species.
• The community includes all populations in a given geograph.ic area.
B. Examples of Community Ecology Stndies
• Community Composition.
(1) Checklist of Aquatic Plant Species of Reelfoot Lake.
(2) Checklist of Salamanders of the Spruce-Fir Forests in Great
Smoky Mountains.
• Community Species Diversity and Abundance.
(l) Checklist and Relative Abundance of Aquatic Plant Species of
Reelfoot Lake.
(2) Checklist and Relative Abundance of Salamanders of the Spruce
Fir Forests in the Great Smoky Mountains.
• Competitive Relationships.
(I) Displacement of Fox Squirrels by Gray Squirrels in Gibson
County Tennessee.
• Predator - Prey Relationships.
(I) impacts of Coyotes on Wild Turkey Population in Shelby Forest
State Park.
3. Ecosystem Ecology
A. Definition and Overview
• Ecosystem is defmed as - a community and its physical
environment including both nonliving (abiotic) and living (biotic)
components.
• Therefore Ecosystem Ecology can be defined as - the study ofthe
interrelationships ofa community and its physical environment
including both nonliving (abiotic) and living (biotic) components.
• By adding the physical environment, this level is given a whole new
dimension to study.
• The physical environment brings on new characteristics to study and
measure. These include phenomena such as energy flows and
biochemical cycles. (see handout of Figure 48.3 NaJure ofan ecosystem from
page &85 ofU!Xtbool)
B. Examples of Ecosystem Studies
• Energy Food Web or Energy Web Studies.
(I) (see handout of Figure 48.5 Grazing and detritalfood web from page 8860/
lextbool). Taken from studies of a/oust in New Hampshire.
(2) As stated in the legend of the Figure, this is a study of who eats
whom.
• Ecological Pyramids.
(I) (s~~ htlIIdout of Figure 48.6Ecologica/ Pyramidfrom page 887 oftextbook)
(2) This represents a study were producers and consumers were
divided into 4 trophic levels (trophic means feeding). These included
Autotrophs (producers) Herbivores (consumers) Carnivores (consumers) Top Carnivores (consumers ) (3) Note the loss of biomtlSS from bottom to top.
(610_ - is the rIIlIrtbn 0/ organisms nwllip/ied by th~ dry wdglft %rgllJ'lic fNdJU
wi,IIill olle orgattism)
• Biochemical Cycles.
(1) The Carbon Cycle - (su handout of FiguN! 48.9 The carbon cycl~ from
page 890 oftextbook). Note that the transfer of carbon into the
atmosphere due to respiration approximately matches withdrawal
of carbon from the atmosphere due to photosynthesis.
(2) Other important cycles shown in your textbook include
• Water Cycle (see handout of Figure 48.8 The
hydr%gic(woler cycle) from page 889 oftextbook)
• Nitrogen CycJe(see handout of Figu,~ 48.11 The nitrogen
cyclefrom page 891 oftextbook)
• Phosphorus Cycle(see handoul of Figure 48.14 The
phosphorus cycle from page 894 oftextbook)
4. Tbe Biospbere
A. Defmition and Overview
• Biosphere is defined as - 'Zone ofair, land, and water aJ the surface
ofthe earth in which all living organisms are found.
• Therefore Biosphere Ecology can be defined as - the study of
interactions ofaU the earth's organisms with the air, land, and water
at the surface ofthe earth.
• In an imaginative way - you can think of the earth's biosphere as a
single, very large organism, with lots of complicated parts and
interactions. Each individual part has afunction that may be
important for the survival of the whole.
B. Examples of Biosphere Studies
• Climate Studies.
(1) Current studies of global warming are examples of biosphere
studies.
• Classification and Distribution ofBiomes.
(1) (see hll1ldoul of Table 49.1 Selected biomnfrom page 905 oftextbook)
and
(see hll1ldout ofFigure 49.4 Pattern ofblome distribution from JHlge 904 oftextbook)
(2) Biome is defined as a major type of terrestrial ecosystem.
l
TAB L E 46. 1
: ~;'
Ecological Terms
Term
De finition
Ecology
Study of the interactions of organisms with each
other and with the physical environment
Population
All the members of the same species that inhabit a
Community
All the populations round in a particular area
Ecosystem
A community and its physical environment.
particular area
including both nonliving (abiotic) and living
(biotic) components
Biosphere
All the comm unities on Earth whose members exlu
in air and water and on land
sofar
energy
heal
heal <{:a-r::~
/
..:::.+ energy
~ nutrient s
F IGURE .J 8.3 Nature of an ecosystem.
C hemicals cycle. bur energy flo ws through an ecosystem. As energy
[ran,formation, repeatedly occur, all the energy derived from the s un eventually
diSSipates as heat.
.\'86
Autotroph.
Herbivores/Omnivores
Carnivores
fungi and bacteria
sh reVlS
- Jetritus food web
FIGURE 18.5 Grazing a nd detrital food web. a... Tan r r o,,'/s :lI ustrt! :e pc ssib'e g-::um '-:)c c ·.·.. eos. F:):"" 2xaT ~ e. J -di. :~ I- C'; :~eci Or" '"' J{S. rT' 2.y be e :.H:en by a hawk. _:o [rophs such as (he tree are producers dkst tro phic. or feedl rg. e'. . e . tr~ fi rs t S:E! r es of i:'Jrra S :l-e :lnrary ccns,u r-: e"s ,ieco r o r.-c ph,c levell , and t e next group of ' '''' '11 als are secondary consumers { third ( rcp h lC ievel ). b. G ; een ar r o'.vs u S\:~ ( 2: :'OS5 DIe d e tr' ~a t :..: cd -,-,eb s. .vr (1 ;.egu"· 'N : - c cr.:- : c." s-r;" e 'jJ:cre ria ar. d fungi of decay =:'Jd webs are descriptions of who eats v,Ihcm .
-=..
1-d -'
:~
-"!fTlains of dead organisms . A lar ge por:ic n of rre se r~ rr a:n 5i are .f .... o rr ere g;-;UJ rg fee d ·•·.. eb dl ,_so"',::::ed ir
nimals in [he grazing food '.....eb. as w hen ro:,ins fe ed e n e..Jr..:n \·JO~f'!"S. '7"ht,;s. c. L..e gl""3.2ir- g foad 'Neb 3r e
a . Tre c"' -;:3r sr'!O In ~re certi tal :ood web are sometimes ~:"e
de: - lta l (::0-: ·..~ ~b are connec ed to o ne another. FIGURE 48.6 Eco&ogk:aI pjramid.
The biomass, or dry weight (gJm'), for trophic levels in a grazing food web
in a bog at Silver Spnngs. Florida. There is a shaqJ drop in bioousl between
rhe producer 14'!'IIeI and herl>iYore Ievef, which Is consistent with !he common
knowledge thai: the dea-taI rood web plays a significant role in bogs..
-is- I()
The C arbon Cycle
Tn the carb on cy cle, organisms exchange carbon dioxide with
the atmosphere (Fig. -\.8.9). On land, plants take up carbon
ioxide from the <l ir, and through photosynthesis they incor­
. orate carbon in to organic nu trients that are food for other
living th ings. When organisms (e.g ., plan ts, animals, and
decom posers) respire, a portion o f this carbon is rehJmed
to the a tmosphere as carbon dioxide. In aquatic ecosystems,
carbon dioxide from the air combines with water to prod uce
bicarbon ate ion (HCO)- ), a source of carbon for p hotosyn­
thetic p ro tists. When aquatic organisms respire, the carbon
dioxid e they give off becomes bicarbonate ion .
.
r .-\RT VIII
............
-:::::::======~5
\ 'W
t Cnl'
Living and deCld oroanjsms contain organic carbon cl
serve as one of the reservoirs for the carbon cycle. The warl(
biotic components, particula rly trees, contain 800 billion to.
of organic carbon cmd an additional 1,()()(}"3,(J()() billion n1L
ric tons are estimated to be held in the rcm ains of plants an
animals in the soil. Before decomposition can occur, some (
these remains are subjected to physical processes that tram
fonn them into coal, oil, and natural g<ls. We call these m<l tcri
dIs the fossil fuels_ Most of the fossil fuels were fa nned d urin~
the Carboni ferous period, 299-360 million years <lgo, when cl fl
exceptionaJly large amount of organic ma tter was buried be­
fore decomposing. Another reservoir is the inorganic carbonate
­
combustion
BIH .·\\I <l!{
CO2 in Atmosphere
720
Selected Biomes
Name
Charaer eristics
Tundra
Around North Pole; average annual temperature
is - 12C' to - 6C ; low annual precipitation (less
than 25 cm); permafrost (permanent ice) year-round I
within a me ter of surface.
Taiga
(coniferous
forest)
Large northern bio me that circles just below
Temperate
deciduous
forest
Eastern half of United States. Canada. Europe. and
parts of Russia; four seasons of the year with hot
summe rs and cold winters; goodly annual
precipitation (7S-150 em)
Grasslands
Called prairies in North America. savannas in Africa.
pampas in South America. steppes In Europe; hot
in summer and cold in wint er (United States);
m~te annual precipitation; good soil for
agriculture.
Tropical rain
Located near the equator In Latin America.
Southeast Asia. and West Africa; wann ( 2~25Cj
and wet (190 cmJyear); has wet/dry season.
forests
Deserts
o polar ice
o tundra _ taiga o mountain zone
• temperate deciduous forest
• temperate rain larest
• tropical deciduous forest
tropical seasonal forest tropical rain forest shrubland
o temperate grassland
o
o
, ... - 'Ivanna
'idesert
rt
the Arctic C ircle; temperature is below freezing for
half the year; mode rate annual precipitation
(30-85 cm); long nights in winter and long days
in summer.
I
I
Northe rn and Southern Hemisphe res at 30" latirude;!
hot (38Cj days and cold (7Cj nights; low annual
precipitation (less than 25 em).