HomeMy WebLinkAboutSUS5009The majority of educational programs for A-level
Biology that are currently avsilable rely mainly upon
monochrome disp!ays with little use of graphics other
than to produce graphs, histogiarns, or maybe diag-
rams of organisms. Now lhac the Research machines
480-Z has been ioined by the BBC Micro and the
Sillclair Spectrum in the Do1 scherne t'or Micros in
Schools (Kewney, G., 1982). the :tvaiiability of such
machines that allow the production of use!.-defined
graphics chiiracters displayed sirnultailrously in a
variety of colours presenis the opportunity to repre-
sent more ot ihe complexity of hiolrigic2:l situations
than w2s previousiy possible. This i'iiciiity, together
% with ihe ability to r-cdilcc considerably the dxrration of
an eupuriment and tn explore situations that might
otherwise be hazardous to experimenter. apparatus, or p -.
I iave material makes compt~ter sincsulatim much iilctr-e
valuable as a teaching aid.
The field observations at Gore Point, Somerset, upon
which this sizni~lation is bused, are described iind
discussed in a previous paper (Wilson, Crothers, and
Oidl~aun, 1983). The essential feature is tirat the usual
zc~naiitrn paktcrns of certain species on thc shore ;~t-c
disrupted by the flow of kesh water down the beach
fionn a sn?a%l Exrkcj~7ir strea1-n. 'The nnatrices @f" values
i,l-ii:i inrd li.iinp, ;i scriei of p;jr:iiiel hnrizont;il irarisecl s
can be plotted as maps to reveal a relationship between
salinity at~d species distribution (figures 3 to 6 in
Wilson et a/.; figure 1). In particular, low salinity at
low water appears to prevent successful predation of
mussels by dogwh~lks~ and grazing of a green alga
(Ej~ieron~t sp.) by herbivores (topshells). This
leads to the development of patches of green alga and
nlrrssels in and around ihc! stream at the top of the
shore. Away from the stream and high water nrark,
predation occurs and these two species are unable to
become successEully established. The distrih~ltion pat-
tern ofthe red aiga Co~nliinil reRecrs that of ssline rock -- pools away fro!~ ehc inRuet~c,c. of the strerir~. .l! his is
typical of those species which have poor tolerance of
both high insolation or desiccatiorl and hrther re-
duction in salitlity of, the estuaritle wiiter.
The coilventinnal pattern on the shore is for inosr
species tc occur in wider or narrower bands parallel to
mean sea le-vei. The precise laisaiiow of each hand
betweert high water mark and Isw water nnark is
largely dependent upon exposure or the organisms to
rough weather (B;rll.intine, 196 i ; Jones, 1959; anil
Lewis. 1964). Changes in exposure are reflected by
rnovemeilt of the hands up or down the beach, with
displacement of one species by another under extrelne
condtrions.
In very gerlerai terms, tlrc effect of any sireanr on
littoral zonatiiin 131a-y depend ilpoit its width, the bank
height, tiqe speed and ~oikaarzc of Cresh water RCIW, nr~d
,-?, the rrresence suspended mitler. 1 hew ir~ tnrua siklill
inliuelice vihcr Ckictors sirclr as siili~~iiy~ ik~jkjidity~
dci~sily, desiccation, tcilipcritiuihc, ant! ilrc s~il>ply oi'
organic matter, which :ire of varyirlg importance to rh~:
survival of'dlfTeieni isrgar~isms c~n the slntsrtt. At Gore
L3o2~n*e, hovie~ier, tkx strekira~ is i~;.irrc~w \i\/i~h YIO bilrll~t?;
aid has o~ly a inodcr;iic id;itc ul flow.
SLII-~I~: f~irii~~:i* i~i~~~oriiijit Fii~*i~~t~~$~ :?I~C!I as I :ii~~fiiil,
illst?i;ltiu!l* l:2tit!*i4"ic5 tiilci ~c~12~~cl~ikt!irth :i!lt%l ti~jiii r;4ll'~,t;?;~
iirc indcpcurlerlt o!'ilow am..! exposure. !-io\nicver, ir w;is
1101 ~~~~ss~\*~~L' i~~$~~~:;ti~'i~ik? nlO8"i' 1 11 ~IC [\'b!6'
:,])CL~[:;? iil~d % ji~lt> 131~1,iit fi$t'lt~~; !\i(b~3kit)i~i*ti ;ibt~~f~, :ik)
nntsx-c3 $laan 2.5 k of RANI is irv;alfcl!>ls;s $12 nP~e i'mr 0301a;~.4
rniridr: jr~lcacie 5) ol' l!so %-8139>11oiic\ A t*i~i3l)k~i1~~1~
Simulated ecoiogicai mapping Ken?
Figure B Map of species
dist~ibuitisn at Gore Point
derived fr~m a VypicaS set of
studentss' observations.
Figures indica'e sample
positior~s at 5 rn intervals
starting froan the stream
centre at High Water
~Vark. Symbols inldicaiee
the presence sf a high
density of india~idrzals to
avoid slaperimpositions;
records of Etztoromi:~pi~u
have been omitted from
points 2,3 and 3,4 for the
same reason. See fisure 2
for identities of r'ymboIs.
:- ph. -'
;I, ~jtaoua, hit it soon beca~3e clear that the data
available were insrifficienrly detailed to y ieid precise
iiuv~ericat rt:!aticiusi.iips bet~vcen the valucs for en-
vir-onmental factors and the responses of the various
organisms. Instead, ir was decided to develop a
program that produced displays which were qualir-
i ativeiy compatible with i he observed distribution
patterns. The maxi~nrim and minimutn for each factor
were srl at 9 and 0 (as trscd by Wilsoil ci id. liir
conductivii y), and the ibrmillae wcrr adjusted empiri-
cally to give ;jil even spread of values. This sirnpliri-
csrion fi*ci!itated pr~giali~tning the comparisok2 with
rhc pi-esel physiological limits and the presentati~~n of
el~e matrices for singlc factors, and also gave wide!
icttpc lor silbscquent interl~rciatiori in gel~eriil terms.
Any i?rccisi. rzl;itic;nship bctweerl these scales arid real
iiialii 5;11~:1::; ( )~ljii he cst;lb!isl:cd sub~cijuentl y if rc-
quircd.
/$ scl-ceir display pru:!uccd by tlic liiiC ccniputcr - * cijieratillg in Pdoiic 3 is 32 Lil~iis oi' 20 contigritru.;
cjji;ll-;li:i.cls Irt.:l~$: ~41611 :a. 1~1l:gxi~~ttal~ of I;sur coIours
(inc~iuiiing i-~lac:iij or; 8lhc :;crcen 211 ciirce, This rcsoluiivn
is t;c~~-l pariiisic to rt:ii/lski,: ~c.oicii4ic;ii s;m plillg rates
~ii~<: i~i~tj :;~~ili~it:~ji lt>js ~IIC ~I~*CJC!U~JI i~jn tjf :jiii~iil~i~~~i
:ji:[~~-~~*j;~ii~~ ~i~~2~>~~43 tji:3il-ii:~tl~"ioj~ ~I~xY~~B, ))i~t:h i,jh III~~II! bt:
r- _l
prtiiiiit:itl !.Y'iiiri pt~ifii tlil2itiliii ti,iiii. 1 t.1 i.ii!{iici: (hi: t;iflc2
" 1 rt*;q~ii~-v-i t;iich j>lottii2j? :*!in a~d j~~'~~vidg,: :;pitci: ['or
~~~fl3$.~1~;~~~<~11 itrit; il-if~**3b~;:L::7+ ii3f2 !*lppc!- hi>* !ii3~*&> of ii2c
:ii:jpj;i> :tnB :jv~j 10 ~~:!I~-CSL*~II the hvai;!i ;~bt-~\t: i i VVPdi
tJdi8ljt* !<Jbilt~%l ij.ll(: iiH!i~::l~c~~, ~,bfv'\@. A/l!~~O~i~,ll i/>t>
j;i:i{j (icit:~ ~:*jci.( t oj/t,:c%i~*d O!il;f !o kli<* t::i\i 01 the :\!ie;i!tl*
tb , j i$iiii ill(: ')jii.;iilj !il [/I(' 4'CilllO
, j- it! i- t! tri'
/*i !;I*ii4<,i'!
After defining thz shapes and ioiours (algae: prim-
ary pmduucer - green; topshells and inussels:
herbivore tnagenta: dogwhelks: carnivore--- red) of
the species (figbir"~ 21, :rppcr beash (red), and cetitral
stream (green). the cur, dnt values of Row and exposure
are supplied from the keyboard. It was illtended that
these f;~cnurs should be expressed on arbitrary non-
linear 10 point ii-itege: scales (0-4) !hr con-veniencc but
it was subsequciltiy found that any nnn-negative
decirnal value is accepted. These can. the21 be uscd to
calculate the sate ohsprcad nf kcsh water :is ihe streal%
Rows down the shore. and the effect of exposure in
welling the upper shore with :pray. The ir;tcrval
between cbb and floc>d tides (uncoveo is estimated
separately with nri ,iiiuwance fix spising or ne:lp tides.
Note rl-a1 the exi~o.;urc scale ihllows tlr;t~ of ioires
(8 = caino r-;ither than than t~f' Raliiri~tii~e.
As thc. inap 3x23 is scaliriod, the ithovc ci~lcul;itions
;are ~dlkidk? ,"br ~ik43811 of' 111~ 25 i-OW5 lind ti1(;3. li"t:~ll!t~ i$rG
used tc cstirrlaie the lociii exlti,surc io :)alii~ity i'rx each
?- %< oB' the 20 calfs ill cadi J*C)V~, 5(hd~ f6i~~11 V~IHBI~:S f'~r
zxi,osiir8e, iiziccive;B, aild saiir~ity arc ~~ili~iir~d wiili
ixubct upper ~HN! lower. i,iiy>Yiologii:iii iiinits ibr c:~cii
spccics. 8 1' itli) ti r ia 1 c L 112
itrier;i~rc:e c.;rnge, \i!i.i~ tilai si7c~ics citt~lrot oc~*ilr in ii~;ti
c-cii. 'l'lic c i,ccuri+ciici; o!' a i,rt.ciati)i* ;liio
!,~~iiide:> !. hc p!*cscili'C 01' [3I.cv til~i- ', si11~2 t!Oj:\.\ lki'i hi
c;sn iisigraic, ;il!-.lh~it 1-;11ial:r- :;!o\\.fy CC 'l"~,'rliQaci^~~ pt;r:si.rbx.i I
~~~~i~~~I~i~!~ic~~iti~~~~) :inti, ;itt;iCi\ id! fil~i ~~c&~t:\"lt~~~*~~ $2li\>#%~k\
~~rc*~ci~it*ci hy io\v si~ii~~i~j/. Sii~~ii;t\-!;/% t!:~ l'tu ot'
itk: ~~~~l~~~~~l~l~~~r/~~~~d )j;tl[tbitl hnil~*Cfi:~ iii; lx!:ii;iii:lii ti!
;lt>:*c"if Of1 t~l/7:B!ik~~~ ;1ctivjiy I-?;? hvt* !*;iiiillk;? ilti i *t3*i*!lith!t
fj;!l4-!iy ;iffi;;il; i'ro~ll i j !h/l\J*
i]i[lt*~ i)!~\#,l!-i* L.yj !-t*J; tiit**\ ll&i) i* :;la,4 f IS\^\\ j4;< ; 13 i)<b
" @ - -
Me- '.=* m '
, - * --
(. - * Me*
I* .I.. sac -- 1- OIY '* w- W'S
L . O 10
M - emma
n
a.
+a*'.<- --
" % * * * * 6
em*
a- -
*- earn
m - e-
** -- * = " w QWW ..-
m a - * . * --
<.-
w* -'.w
w -
"W --
*es.s*
(LB^u* ma- - -
car nm Lxxxama
0 "0
o e
C61- ma0
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us- " * *
-a- *.-
Siroulated sco-;\logicai mapping Kent
Figanre 3 Print of screen dtsplay: full display sr stlore sl~owiag species d!stn.ibuticsa~s far a strear11 facjv~ r.;lk 4 Ila~tl ;~l.n
exposure of' 4. On the scrmrt, the ;.upper beach wc>saici be red, the %GXI bBi~ck and the ceneral stream green, C'oic~~u.:, of
other symbols would be as g4vt:rnr for figure 2.
i -"- ciiflcrent each time, giviilg the illusion of repeated 1 he defiilitiori of" graphics char:ictcrs alld the coil-
r;aini~lirig in ;r srabic eiivii,oninent. I'or exam1,lc in trol ol'coloiir display are generally cc>mputi:~- sl~ccilic,
uui.cessive yc~s or t).; successive investigators. so will not be dcscvibcd hcrc. 'fhe oper:liions at eiich
pa1 ~iclll2kr li11c ~~~ill~3er arc:
260 keel, {ally of' uul-rent cell i?o?;iiii,ll
27";clwulale :i;~iii~iiy
tBdg8-@gham 110te~ %%I st:t el~acowcl- in strc;;n-ern dt:i"kt
h icgnrcfit ofthc pi-ok;!,r;in-i ciealinh: wiih syrnb:,l display 285 print clirrciit s';tlr e ii'ontl factcira Ji .i;l:i\ lcctc~f
J 1 'I it 1 r fig 5. 1 9 3 5 0, 5 hrlcnch to ncil f-.ii'ii ;ifi-.\r-ilitig lo
[-L. nciicd tijar iiiK' B;i:,ic ;iliocv:i cck iain iihcrties to i2c. i!ispliiy :ieicctcd
i;ike~~ that i~t:i+r-flir i CI; pacltii?g oi* thc progranr inlo tt 295 skip topshcii symhcii prii~t it' ;i!g;ti tiiaijl:!v st~1i.c-
:- :LC pi ' ti - I ieri
1, ti 1 J ( 1) ;iiiii i:Al.Sli' [Of 300 set pl ribiihility i'~1~ tvpshcll lli*ix i I~~~~~
iii;jy bc ii?,i.L( iii ;li-llhlili:tic ~~l)j*i:'i~iOll~, [ill(: 11111#1h"$'h 305 :Kt t(>i?:;k~~Ij [?~Ok~:tkji/iiy jl&g
: .i h it . I . . 311) prjiil I~>!IS!IC~~ :iyt~k!joi 11' t*oiitjjtjt311:~ :~i,>*! p!(~-
> i'(ji ji:...~ it:(: ~~:i!'l:!~-l!i~ 1l~:Vci pO!ll!.?, to tile illl!>:@,illj? k7;!l-)iiii>/ !3~*i-!llit
Y ' , rp-
Ijt,sjj[jv J]~l,. i-4: ,'I i lil.cti .: !*O1liiwi.ll iry illc $20 ilr-:l!iii! ;it-c,ii? tlilil: 111 biriritkklihl iiiit i'~.~ll : 4 ~\iii~~~t
:k13{~; 0[1f-i;1 tt: l(l()!j vi; k"i:hijjt * pO:>:sji?it? 01 111 itl\t ~1
-@
B
Simulated ~coiorpicai mapping Kent
gigune 4 Print of screen ciispiay: disisitiltioz~ pttern oT mussel:, with respect to saiinity (organism 4 3:16 fi~~tojf. 3
figure 2) for a sit-er:nr flow r;.ie of 6 and sn expilstkrc of 4-& Tlae rnussclt; ;tppei~s as it horse-shoe shaped k~:d ;if s;-llinity
wluex 4 ancl 5. 01~ rhe screen the culoriss tt: ilpper beach, xexr itnd musse%s wouii4 be iis given in fig~ii-cs 2 and 3, and the
rl-iatrix ~rr%tn~;rals wo~sid be green.
prcibai-~iiity permit
450 s'ic ip ilogwirt.iL syllll,c~l pt+irlt if' :ilussel disi?l;r y
:$~lc;t;r ~d
5~2~ ?.I pi-cal 7~1 i..- diiy fiir ticigwllelk pi-esence
5 10 print tdtr;fwh~ik s,yi,il,oi il' ec:l!ti;iirln!, and prow
~~~1'111~~
Ocii; 6,i;q' I~~LCS?~ if' cicigwl,,:iii possiblc
.!it: ~:t uppcr skorc iina~t hr rnt6sk;cls in sire;aiar
$rid1 print :i"~e~"~:t:i :;yxrlh<lf it' ce?,x:diii<;isc ;trb.: pro-
f,,, aru!.rjfl~y , ~ICTT~I~:"
i?"U,l :bklj; < yuj ~l//i!/~! [~!-i!lt of k1ci :;p2c:ic5 :ili*c:tldy
p! w.,ll[
(/!(i pi-ijii i 'i~r !i/iiiilr *,yiiiii:~i if' !.tiiiilii icirr.; ;irrti l~io -
;;;il>jlj; 4 1 qllb
if,[; A:)~;J&* lpij :t) ~3q;*f lyjj
syrr,bo!, alld prob:ihiiity that ail org,,nisnl will occul. It
C!ICL~~ jiiii~)~. V~~IIICS ili:iiitl~~ tfl2 presel iiiuii:,, ilicrc -
lncnth i.iN if' preserlcc is possible, and ptiflts tiic
;ipl~l'opriate b3y.a 501 if' t l-~c lit'ol?ai~i!ity pi:l-m;is.
i~~~~.~$,~ I $.r . i?i:tail~ of the sin~ulation prc~gr;lnl il,;iv hi:
tr":-,i ;iint-t.ji Fr-e~ulr tl:c a u~i~t-~i., wlri%lb a vca sirm ol'iilis ;i.i~td, ii
~~c~~~tc~~ ~~iA~lg~-:t~ll ror i B ijc illOd~~! f3 ii rc jlllh!i:;ilL~~i 17~1
Ci:iri:~~k(J c'on~p~iti~~g> 35 Dciti~ 1 Mi, !31yik~t~ut!~~
1 azTT'Yk: i'"?) =.&-ir,/-r <jZ#i,~[~jc,,b- ; ~~,'-j.-c~~j~ <c"$.-.T j , ,, :?:.,-+- -: ;c~ j ,- .- .. I*.
' - :-. ' .-- ' , , -, . t: '. - -K. ' , -. -. . a ,,, ri
jj:!7ar-s lgeBr 4j. 5 C, .st-r- 7 - I ~.~,b,~a~rtb of Ciorrs Pr~int sir?~~ni;ntioi? flrisgram that ctcals with tlse indivicirlal cell display. See relit fc~r; iJee;;l,ili;.
- I<eferegBces !Vflscln, C', PvI., C~i7tltitfrs~ $9, Ha. and O'Idlwrn, J. I-!. (1483)
Bit'ni;.na~tinc., br, .1, ( I96f j bioicsgicalt y-defi~~ed exposure Realized niche: the etTccts of si21:ill stream on seia-
scale for I klc cc~~npariitive dcscripiiori ol rocky S~QT~S, shore $istribr!",ttrl palteras,
fiu!'d ,"jt:rsrc/ic.,s;, B (31, !- li! E~J~t~*~~ijo~l, 17 ( f ), 5 1 -58.
Jones, iY. E. (t 959) 'F'i~e rfft:crs of cxpraslare 01% the
zl.irnatic.>~ 01' algae rslz B;triJscy Islktzl<l. Rcli. BIJ~~LCC~: Oh,;.
(Extr~sct), 1 6. --, , . ------------"..%p-
7 Kcwncy, C. 6 t 982) bEoi-c niicn-ais for srhotjle;. Per.soizcr/ I ix: autho~~
C-oji~pzirrt- Sliirr-ill, 5 (9), 89 91 , .:', bi'. KBI~~ i~ la Lccrntrer iir Bio(og.i in the. Ri;ri(~~~i~~~~il/ rrJ'
Lcwiii, 1. i 964) 7;11a~ ~a'r~io,q-i- of ~"cit,ic,i; .~hr,r.c.i.. English lktrrr~iif?iii~'s ritj~: Si'i~wi*o, Soitlicrsc~r Coli(~3~1;'c rl(' .4r-ts curd
&jniversities Press, TC>C'/?~Z:>~U~,~', >~i!~folr, S01'71~r.sef TA 1 3.A X.