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Interspecific Competition 11/19/2015
ONE-SIDED 8X11 AVAILALE
Interspecific Competition
Str!""#e $et%een species for reso!rces& '($it(ts& for
#ife
A cornerstone of e)o#!tion(r* eco#o"*
+'ere (re t'ese species competin"& (n, 'o% ,o t'e*
speci(#ie.
Affects t'e pop!#(tions of t%o or more species ne"(ti)e#*
o Difference species compete for t'e s(me reso!rce
Competition
Interspecific ,ifferent species
Intr(specific s(me species
Scr(m$#e competition "ro%t' (n, repro,!ction (re ,epresse,
(n* ,ifferent t*pes of competition
Cons!mption
O)er"ro%t'
erritori(#
Enco!nters
C'emic(# inter(ction p#(nts '()e ( #ot of c'emic(#s& simi#(r
to
$(cteri(& for competition since t'e* c(n3t mo)e4 t'e*3##
,!mp (
poison into t'e soi#4 secretion of c'emic(#s t'(t in'i$its
"ermin(tion
of ot'er species
Lot(-Vo#terr( o,e#
Species 1 ,N2/Dt 6 r1N171-N1/1
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See ( ,ecre(se in o)er(## pop!#(tion "ro%t'
6 c(rr*in" c(p(cit* of t'e species
A competition coefficient :!(ntifies t'e
;er c(pit( effect of species 2 on species 1 7(#p'(
;er c(pit( effect of species 1 on species 2 7$et(
Competition effects on pop!#(tion
E
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1 species 1 (#%(*s %ins o)er species 2
o if c(rr*in" c(p(cit* is "re(ter t'(n competition
coefficient&
t'en species 1 %i## (#%(*s %in
o (t some point species 2 %i## re(c' its c(rr*in" c(p(cit*
%'i#e
species 1 %i## sti## $e incre(sin" to its o%n c(rr*in"
c(p(cit*
o it %i## e)ent!(##* force species 2 into e
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o %'en 2 1/(#p'( simi#(r sit!(tion
o %e '()e (n !nst($#e e:!i#i$ri!m point4 it c(n $e st($#e $!t
if
%e '()e 'i"'er (mo!nt of species 2& species 2 %i## %in
(n,
)ice )ers( %it' species 1
In t'is m(t'em(tic(# mo,e#s seems #ie e
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ro%n tro!t 6 mi,,#e e#e)(tion
Cree c'!$ 6 #o% e#e)(tion
'e* (## fi"'t e(c' ot'er if in t'e s(me #oc(tion4 %(nte, to #oo
(t 'o%
temper(t!re (ffecte, t'em
oo ,ifferent fis' m(tc'e, $* sie (n, p!t t'em in ,ifferent
temper(t!re r(n"es @o!n,
o Cree c'!$ )er* $(, (t competin" (t #o%er temper(t!res4
,oes "re(t (t 'i"'er temper(t!res
o roo tro!t (n, $ro%n tro!t (re prett* simi#(r $!t $ro%n
,oes
$est in mi,,#e e#e)(tion
o roo tro!t ,oes $est (t 'i"' e#e)(tion (n, co#,
temper(t!res
En)ironment(# con,itions (re )(ri($#e o)er time4 one ,(*
somet'in" is "oo,m(* not $e s(me #(ter
If *o! '()e eno!"' c'(n"e& one species %i## ne)er re(c'
its
c(rr*in" c(p(cit* $ec(!se t'e en)ironment is (#%(*s c'(n"in"
(n,t'ere3s (#%(*s competition "oin" on
+e r(re#* see competiti)e e
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Experiment:'o% p#(nts respon, to n!trients
Essenti(# n!trients t'(t (## p#(nts nee,& N;
+'en 'i"' concentr(tion of n!trients p#(nts "ro% ( #ot $!t
imp(ct is
#ess
If *o! r(n"e t'e n!trients t'e p#(nts ,o %e## in ,ifferent
en)ironments Lo% %(ter 6 #o% o
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e
