Population Distribution How does population distribution afect the environment?
Why? Alaska contains over 127 million acres o untouched orest land. It is the largest state in the nited !tates" #et with a population o nearl# 7$$"$$$ people it has the same total population as Austin" %e&as. 'ew (erse# is one o the smallest states and home to a population o nearl# ) million" but almost 1.* million o its +.+ million total land acres are untouched natural woodland. ,hat are the reasons or the wa#s populations organi-e themselves" and what efect does this organi-ation have on the environment?
Model 1 – Population Density and Distribution
individual organism
1. /e /eer er to 0ode 0odell 1. a. ,hat do the dots in the diagrams represent? repres ent? rganism living individuall# b. ,hat
do the bo&es in the diagrams represent? re present? The area of the Habitat organism live in.
2. alcu alculate late the the area o a single habitat. habitat. Total area of single habitat is 4m! 3opulation 4istribution
1
5. onsid onsider er the arrangement arrangements s o the dots in 0odel 0odel 1. a. 4escribe the arrangements o the dots in habitat 5. %he habitats in habitat 5 are more likel# organi-ed and evenl# distributed. b. 4escribe the arrangement o the dots in habitat +. "n habitat 4 the dots are grouped together. +. 6ill in the table below b# counting the number o individuals in each habitat in 0odel 1 and then calculate the area available per individual. Habitat $rea %&m'( #o.
#o. of "ndividuals
#o. of "ndividuals)*nit area %Density(
1
+
51
7.789m:
2
+
+
189m:
5
+
12
589m:
+
+
1
5.789m:
+ 7 . /eer to the the completed completed table above. above.
1.789m:
a. ,hich habitat shows a high population density ? Habitat shows a high population densit# densit#.. b. ,hich habitat shows the lowest population densit#? Habitat 2 shows the less population. ;. 4raw a vertical line through the middle o each o the the bo&es in model 1.
and the right side =b> on each bo&. omplete the table below or each hal o each habitat. Habitat $rea %&m'( #o. 1 2
#o. of "ndividuals
#o. of "ndividuals)*nit area %Density(
a
2
1;
*89m:
b
2
1
7.89m:
a
2
5
1.89m:
b
2
1
$.89m:
3opulation 4istribution
2
5 +
a
2
;
589m:
b
2
;
589m:
a
2
11
.89m:
b
2
+
289m:
a
2
2.89m:
b 2 2 189m: 7. 6or which o the habitats in 0odel 1 is population densit# ver# similar between sides a and b? Habitat 1 and 5 *. 6or which o the habitats in 0odel 1 is the population densit# densit# uite diferent between sides a and b? habitat 2" + and
2
3@I< Activities or High !chool Biolog# ).
1$. ompare and contrast the terms population densit# and population distribution. Epopulation densit# is considered to be the number o individuals per area and population distribution is the organi-ation o a group o individuals in a given area. 11. Assuming the population si-e sta#s constant" constant" propose at least two actors that might cause a population to shit rom a low l ow densit# habitat to a high densit# habitat? Eloss or lack o resources such as ood and change in the environment. 12. Animals such as lions or wolves oten show clumped clumped distribution. @ive a reason wh# this would be advantageous or these animals.
3opulation 4istribution
5
%his t#pe o animals actuall# mark their territories so that other hunters or predators would not enter and take awa# their resources or ood" the# hunt in groups and remain in their own territories.
15. ther than social reasons" list an# other other actors that ma# lead to clumped distribution patterns in populations. 6actors that ma# lead to a clumped population would be because o the availabilit# o resources such as ood and water are onl# ound in that place" another actor would be or protection rom invaders or predators" a clumped population would probabl# cause predators to go awa# or as a whole deend their territor# terri tor#..
1+. 6or each o the organisms listed below state s tate the t#pe o population distribution and population densit# o their habitat. @ive a reason or each answer. +rganism
Tigers
Distribut ion
Density
,eason
niorme d
%igers hunt alone and more likel# mark their territories.
lumped
high
BisonFs are herding animals
lumped
High
Ants live in organi-ed colonies" man# o them in a nest that is built perectl# and ood is stored.
/andom
High
Because o wind dispersal it is taken to diferent areas and grow ar apart rom each other.
uniorm
high
%he# are evenl# spaced to avoid competition
-ison
$nts
Dandelion s $pple trees in an orhard
Model ' – /ators $0eting Density /ator 6ood suppl# /ainall
Density Dependent G
Density "ndependent G
6l o o d
G
3arasites
G
Acidit# 4isease
G G
4rought
G
ompetition
G
3redation
G
1. /eer to to 0odel 2. a. ,hich actors are dependent on the population densit#? dens it#? 6ood suppl#" suppl#" parasites" disease" competition" predation b. 4escribe how the ood suppl# would be afected b# the population densit# densit#.. The population would be competing for the same source of food found in one specic area. c. 4escribe how the levels or spread o disease would be afected b# population densit#. In order for disease to be spread there has to be other carriers, so if there was to be a large population disease would spread in a short time probably causing a disease outbreak. 1;. ,hat do all the densit#Eindependent densit#Eindependent actors have in common? According to some inormation gathered" densit# independent actors are more likel# to be environmental actors. 17. In #our own words" dene density dependent and dependent and density independent b# independent b# completing the sentences below below.. 4ensit#Edependent actors are normall# afect directl# b# the densit# o individuals in an area. 4ensit#Eindependent actors are normall# unafected b# the number o individuals in an area. An earthuake would not bather i the population is large or small it would actuall# strike an#wa#s" it is b# nature. 1*. 4ensit#Eindependent actors and densit#Edependent actors ma# be interrelated. 6or e&le" a lack o rainall that causes a drought will impact the ood suppl# in a habitat. 3ropose another pairing o a densit#E independent actor and densit#Edependent actor that might occur. occur. 4rought will cause limited resources and competition will rise. Another actor will be that an earthuake will cause change in environment and once
3opulation 4istribution
again limited resources and decrease in population depending on the habitat.
+
3@I< Activities or High !chool Biolog#
2tension 3uestions ,ead This $llelopathy Callelon Callelon =o each other> and pathos pathos =to sufer>D is the chemical inhibition o one species b# another. %his phenomena is reuentl# ound in plants where one species o plant releases a chemical into the environment that inhibits the growth o another species o plant. An e&le is the reosote bush" which releases terpenes into the surrounding soil to inhibit the growth o other plants. 1). 4escribe what might be observed in a habitat that would indicate indicate a plant species is allelopathic? E!ince that t#pe o species releases chemicals and discourages other living plants to live near it we can conclude that when observing the t#pe o species we will see se e that the# are widel# spread evenl# eve nl#"" ound b# itsel" and that species living near it are either weak or tend not to survive or long. 2$. onsidering what #ou know about about population distribution" what t#pe o distribution is likel# to arise as a result o allelopath#? (usti# #our answer using complete sentences. Ebecause the# are the# are widel# spread evenl# the# can be considered uniormed" also i within the same species the# tend to survive within their own t#pe o habitat and ma# result in a clumped population.
21. ,hat would be some advantages advantages o allelopath# to a plant? plant? !ince the t#pe o species are widel# spread the# tend to cover large habitats in which other plants tend not to survive and there would be less competition or resources" and the abundance o resources would cause its population to increase.
22. ,hat would be some disadvantages disadvantages to the ecos#stem where allelopathic plants grow? !ince other species o plants cannot grow near it there would onl# be the allelopathic plants growing at a uniormed process and later since the#
3opulation 4istribution
7
would be the onl# species living in the area the# would begin growing at a ast rate and create a clumped habitat.
25. Is it likel# that a species that e&hibits allelopath# would evolve over time? time? J&plain #our answer using what #ou know about the mechanisms o evolution. Jvolution is change in the heritable traits o biological populations over successive generations. Allelopath# would eventuall# become the onl# species living since there would be less competition and would probabl# cause new species not to develop or e&ist.
2+. %he sorghum plant releases the alleloto&in sorgolene that disrupts mitochondrial unctions unctions and inhibits photos#nthesis. Brainstorm with with #our group some positive applications or this alleloto&in. E Jfe Jfects cts o o weeds weeds on plan plants" ts" it it serves serves as grow growth th regul regulato ators rs and and natura naturall herbicides"" to promote sustainable agriculture. herbicides
3opulation 4istribution
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