APTER ONTsatnry/n M s.tafrard' ruPnt

Proiect Title:Proiect by:Purpose ofProiect:

TABLE, OF CONTEI\ITS

Methods of data collection

Literature Review

Presentation of data

Analysis of data

Discussion of findings

Conclusion

Recommendations

BibliographY

Appendix

The ecology in the school farm

Chene MohammedTo study a manmade ecological system at Couva Government

Secondary School, Tlinidad (the manmade ecological system is

the school)

The main ecological systems in the fatm arc;

(a) pond ecology

@) ecology of the evergreen trees (which include fruit trees)

The ecology studied will be compared to similar, natural ecosystems'

PURPOSS OF Trrs I:RSJT,CT * oW3,CTrr/E

The main objective: Adaptation, Species diversity'

(1) is to study Charles Darwin's theory on

(a) Natural selection(b) AdaPtation

(2)Thefarm,sbiogeochemicalcyclesandcomparethemtonaturalcycles(3) Competition-( fish species and trees)

(4)Speciesdiversity(thefishesinthepondandthefarmtrees)(5) Growth rate (fishes in the Pond)

VARIABLTSThe constants:-. fish food. height of the pond (water level). time of sampling of water hyacinttrs in the pond

o size of the pond (16ft x 20ft x 5ft)o size of the filter pond (4ft x 4ft x 3ft)r size of the farm (30ft x 1.32tt). experimental Period 6 months. fixed number of evergreen trees. water level of the pond maintained by topping up on a weekly basis by students

. type of food to feed fishes- red Tilapia fish pellets

r time of day the fishes are fed; -morning period. sampling time on the 15th of every month. equivalent amounts of plants in the pond

Manipulative variables: -r growth rate of fishes. growth rate of water hyacinths in the pondo feeding relationships between organisms on the farm

Responding variables:-o the number of fishes at the end of the studyo the number of water hyacinths at the end of the study. changes in the size of fish and water hyacinths at the end of the study. species diversity of the fisheso population of the fishes and water hyacinths. adaptation of the water hyacinths

CHAPTER 1 THE STUDYOF ECOLOcY 25

M&TTiCI$ OF DAIA COLI.uETIONData collection started in October 15th 2008. It was decided that data would be collected onthe 15th of every month for the next six months. During this period, the water hyacinthsare observed and pictures are taken to show adaptation of these water hyacinths in the twofilter ponds and larger pond.

At the end of the six month period, the pond would be emptied and its species diversity iscalculated. At the start of the project 135 Red Tilapia fingerlings were placed into the pond.The trees in the farm are counted and listed according to both their common name andscientific name.

Data was collected by the students in a rotation system to ensure that all students tookpart in the project. Groups were assigned to data collection for different months to collectphotographs as well as maintain the pond's water level every few days.

Also with regard to the collation of data of the trees on the farm, different groups wereassigned to check the number of trees, categories the types of trees by the local names andto research the scientific names. The data was revised a number of times to ensure accuracy.Groups of students were also rotated every morning to feed the flshes in the pond.All activities were overseen by the teacher.

LTTERAT$RS ft.gIrINXT1' Ecology is the study of organisms in their natural surroundings and the word wascoined by the German biologist Ernst Haeckel in 1869, fully ten years after Charles Darwinpublished his theory on natural selection.

This research project is based on the school's farm and the school's pond located on thefarm. The dimensions of the farm are 30ft x 132ft. The variety evergreen trees on thefarm ranges from large Pomerac trees (Syzygium Malaccensea) to the Poinsetta (EugeniaFloribunda). The farm area also consist of a few crops that students grow.The pond is 20ft x 15ft x 5ft in dimension and was built in December 2006. Saran nettingwas used to line the pond to prevent the fishes from expanding the pond size by digginginto the sides of it. Also a submersible pump was placed inside the pond. In addition thereare tvvo smaller filter ponds that help with the flow of the water in the pond. This ensuredthat the water was kept clean and also to prevent the death of the fishes.On October l5th,one hundred and fifty (150) Red Tilapia roughly three centimetres inlength (3cm) were placed in the pond . This would lead to the research findings on thecompetition factor between the fishes as they would compete for food, space and mates.2. Competition is the utilisation of a resource in short supply by two or more organismswith the result that at least one of the organisms grows and reproduces.Research is also being conducted on the water hyacinths and competition for light andspace in the large pond as well as the two smaller filter ponds where factors such as spaceand light are limited. Here is where adaptation would be observed.3. Adaptation is where in an ecological or evolutionary change in structure a function thatenables an organism to adtust better to its environment and hence enhances the organism,sability to survive.

At the end of the six month period, it is expected that the pond will reach its carryingcapacity with respect to the population of the Red Tilapia fishes.

4. Carryir1g capar.ity is the maxirrrum popr,ilattcrn oi'a .qivt:; ipr:. e5 'Jhai :j,.n €i'aj'.'!:il ' ...

suJlllcrt .i,vithout i;eing degracled or rJ estroired iri tlie l'{i.t-it: 'i'':.} i !-ir: .-:r':1:rrig rapi:. i " , '

beel,eee,led,b-,Slrrtay i'iotnrithollt ieSSenitrg the s'l/-itiinil at,:",jt7 t' " t'.',' 'i l - : ' --run. Also at the end of the six month period, the pond would be drained and the biological

diversity calculated.

5. ilioiogira,i |iiversity refers to the variety of life-forrns, c,lmrncni,v e.r';ple:,;ed :'s i:'i': :-i'i'-r1lel

of species ifi -n5- area, cr ti:.e nr:mber of genetic t;vpes in ali area. These species would also be

included in the food web drawings of the farm's and ponds ecosystem.

Quotes1. Ecology- ENIVRONMENTAL BIOLOG! authors- Michel Reiss &Jenny Chapmanl

published by- Cambridge Unive$ity Press 2004

2. Competition- ECOLOGY PRINCIPLES AND APPLICANTS 2nd EDITION, authors'J.L

chapman & MJ Reiss I published by cambridge university Press 2006

3.Adaptation- ENVIRONMENTAL SCIENCE Toward a sustanable future 8th EDITION ,

authors-Richard T. Wright & Bernard J. Nebel 2002

4.Carrying Capacity- ENVIRONMENTAL SCIENCE Toward a sustainable future 8th EDITION,

authors- Richard T. Wright & BernardJ. Nebel 2002

S.Biological Diversity- ENVIRONMENTAL SCIENCE Earth as a living planet 6th EDITION,

authors- Daniel B. Botkin & Edward A. Kellerl published by-John Wiley & sons 2007'

RE$l-rtil'S

tt:

Table of plantCOMMON NAME SCIENTIFIC NAME NUMBER OF PLANTS

Pomerac Syzygium Malaccensea 10

Citrus Citrus pp 51

Breadfruit Arto Carpus Altilis 2

Noni Morinda Citrifolia 1

Cocoa Manilla Grandiflora 2

Plum Spendias Monbin z

Palm Phoenix Dactylifera 8

Banana Musa Accminata t20

Coconut Cocos Nucifera T2

Mango Magifera Indica 8

Ceries 2

Cherry Eugenia Floribunda 2

Pommectythere 1

Poinsetta Euphoria Pulcherrima z

Coffee Coffea Arabica 2

Duranta Duranta Erecto 2

Soursop Annona Muricata 1

Ficus Ficus Virens 2

Poui Tabebiua Ligulans 1

rFIGURE 1 shows the types of trees in the farm

CHAPTER 1 THE sTUDYOF ECOLOGY 27

PRESENTATION OF DATA

Dlagran 1. Showlng a natural carbon cycle

(4)DEATfl&DECAY

Diagram 2: Carbon cycle on the school farm

fAgBGirsmlgone{?

p{Trn,nrtmsplwna

PHOTOSI\TI{ESIS

RARE

COI1BUSTIO\

.,''q&@XlF,',

'eOArS*{JlSffi'CRCAI"IC

coMmL${sss€

CRTSFPT"i$TS

:l

I

[ATF(BYAliht{ts

6K*n!{iflffi;Fw!{n*

\ tl€*XIM*LS

RTSPIRATIO\

EATE-\ BYrISH

DEATH

&DECAY

ryfry..-, ;

' ,' l''.

DEATH A\T DECAY l

I

I

CHAPTER .I THE STUDYOF ECOLOGY

Results

Organisms in the school pond

Tilapia fish

Local blackconchlsnails

Water beetles

Killy fish

Cascadura fish

0.00% 10.00% 20.00% 30.00-elo 40.00% 50'00% 60.00% 70.00% 80'009{

Figure 3 shows the percentage of organisms that were found in the school's pond at the end

of the six month period.

0.489i

0.95%

0.37%

Size of Tilapia Fi:

50%*-:-40%*'-

3Oc%-:'

... 1.0.5096

I o.soe6"*T* e -

".oe "r.."" ".C ,.""CogJ .J ^""". .d

"-u-tt"" o."r-"* """ _o*o"

Figure 4 shows the size categories of the Tilapia fish that rrere found in the school's pond atthe end of the six month period.

g Organisms in the school pond

BIODIVERSITY CALCULATIONS

Number of organisms found in the pond:

. CASCADURA FISH- 3e KILLI FISH- 8. WATER BEETLES.4o LOCAL BLACK COCNH/SNAIL- 233r RED TILAPIA- 593

SPECIES DIVERSITY N (N - 1

SpeciesDiversity, D=t*j,

N = total number of organismsn = population of each sPecies

D-

i

I CALCULATIONS. Species diverslty of the pond'

n_u = @4 - 1) + 233(233 - 1) + 593 (s93 - 1)

841 (840)

z1z1 asO + 4(3) + 233(232) + s93(592)

706440u = 6 + 56 + 72+ 54056 + 351056

706440T\--" - 405186

D = !.74

CHAPTER 1 THE sTUDYOF ECOLO6Y 37

CALCULIITIONS. Specles dlverslty of the farm trees.231(231 - 1\

L2O(120- 1) + 1(1 -I) +72(1'2-1) +2(2-I) +2(2-t) +2(2-I) +2(2 - 1) + 8(8- 1) +

2(2-r)+2(2-1)+1(1-1)

53130rt = 2 * 255gpZ + 56 +0 +2+ 90+0 + 14280 + 0+ 132 + 2 +2 + 2+2+ 56 + 2 + 2 +O

s3130T'\--" - r7l8z

D = 3.09

FOOD lvEB SHOWING THE FEEDINGSCHOOL FARM

-_^..-.* *r'

Frult Bfits ,/l/'l '

allrllt

G*terpi$aru'S rijil'

OF ORGANISMS IN THE

iiI

!la_irt!,

I

t\

TerrylltesGmsclwprt'i,

"ff.

AphldgrS

I

!tIi

.tII,i

It

.tII,l j

,J':l'./. drcpn

Figure 6 The food web showing the feeding relationship between organismsfarm ecosystem.

Trees

in the school

2(1)+s1(50)+2(1)+8(7)+1(0)+2(1)+10(9)+1(0)+720(It9)+1(0)+12(1'D+2(I)+2(1) + 2(L) + 2(I) + 8(7) + 2(t) + 2(1) + 1(0)

CHAPTER 1 THE sTUDY OF ECOLOdY 39

A&;,&g,vsl$ {,}F i}.434

The ecology of the farm consisted of the ever green trees on the farm as r'r'ell as the ecology

of the sch6ol,s pond. Figure 1 shows the tale of the different species of trees on the farm

by both their local names as well as their scientific names and the amount of them found'

t-his tabte was used to calculate the species diversity of the farm ecosystem with respect to

the trees. The species diversity of the farm was 3.09 which indicated that the school's farm

was a complex ecosystem which made it very stable. The species diversity of the pond was

calculatedlt the end of the six month period. Figure 3 shows the different animals that

were found when the pond was drained as well as the percentage of the animals that made

up the total pond ecosystem population. The species diversity was calculated and was found

toAe t.Z+which means that the pond's ecosystem is very simple and not stable'

With reference to figure 4, the development of the tilapia is shown' There are a few fully

grown fishes in the pond as compared to the 55o/o of the fish population that is still in its

ingerling stages. This shows that the tilapia population is still increasing in the pond with

,.uiity avaitaLte food and mates. Their only limiting factor would eventually be space'

In the pond Kiui fish Cascadura fish were found in small numbers. These were not

intentionally included into the study. It was realized that during the flrst pond draining a

few Cascadura fishes hid themselves in the mud. The Killi fishes have entered the pond in

various ways to be discussed'

At the start of the proiect 135 red tilapia fingerlings were introduced into the pond. The

tilapia population has increased to 593 fishes in total. This shows that there was a period of

"*ponentiat growth among this species in the pond until space became its limiting factor'

With respect to the water hyacinths, figure 2 shows their development for the six month

period. ti was shown that during the first four months that the water hyacinths were

iuccessfully adapting however due to other influences and situations, their adaptation

showed to be unsuccessful by the 5th month. They were dead by the 6th month and

another water weed called "Duck weed" adapted to the conditions as seen in the picture for

the 6th month. The adaptation of the duck weed was due to its favourable conditions which

the water hyacinths could not cope with.

The picture below shows the "duck weed" adaptation at the 6th month period.

Here the "duck weed" can

* {rt be seen adapting while the

i:, i. 1,t *j

rvater hr-acinths die.

Flndings1. The water hyacinths cannot adapt very easily to changes in conditions of water

temperature

Z.Thetilapia flshes do not have problems with population increase since they do not have

strong competition for food , space and mates between other fish species. They however

woutd be aflected by the limiting factor of space in the future. Also with a large population

there would be competition for food among themselves'

3. Also some species of fish are more naturally equipped for survival such as the Killi fish

which were not introduced into the pond by the researchers but were introduced by various

theories.

4. The farm is a stable and complex ecosystem for its size due to the fact that it houses

varied species of trees.

5. With respect to the biogeochemical cycles, there is no difference in the carbon cycle in

comparison between the firm's and a natural cycle, except for the rare forest fires that take

phc6 seasonally. However there are differences between the nitrogen rycle as well as the

water cycle that are influenced by man.

CHAPTER 1 THE sTUDY OF E<OLO6Y

NISCUSSION OF FINDINGS

With rcspect to finding 1. Water hyacinths cannot adapt easily to changes in conditions of

water temperature. This was due to pump failure of the filter ponds that regulate the flow of

water within the pond. The dead roots of some of the water hyacinths got sucked into the

pump and caused technical difficulties. As a result the natural conditions of a fresh water

system were changed. The flow of water kept the pond water at a constant temperature

however this obstacle caused the temperature of the water to rise as well as the lack of oxygen

in the water killed the water hyacinths. As a result another aquatic weed developed normally

called ,,duck weed" since all favourable conditions were available for it to develop and adapt

and survive. However, this water weed is a pest as it was seen within 3 weeks it covered the

entire surface of the filter ponds, suffocating any tilapia fingerlings that were in these filterponds as well. Upon investigation, a foul stench had developed during attempts to move the

duck weed for analysis of the filter pond's condition.

Finding 2 showed that there was little stress placed upon the Tilapia with respect to

reproduction since there was a lack of competition and availability of food even when

the tilapia pellets did run out at one point in time the fishes fed on he roots of the water

hyacinths.lt can be seen that from 135 tilapia fingerlings that were place t the beginning and

the increase to 593 tilapia total. However with the growing population and the competition

for food many of the fingerlings are eaten by adult tilapia in the process for competition for

food.

With respect to finding 3, some species of fish are more equipped for survival since they were

not introduced into the pond system by the researchers but ended up in the system in many

ways. One species of fish in particular is the Killi fish. They can be found in drains and can

survive in little moisture. They could have found their way during the rainy season due to

surface runoff from the near by pond (approximately 50 m -75m away) they tend to follow

the drains 'hopping' and found themselves in this pond. Another theory is that during birds'

feeding some of the fish may have fallen from the birds claws and into the pond/nearby

drains (dispersal). The third theory was that the very tiny Killi fishes were taken up / scooped

up during evaporation and remained in the atmosphere then were dispersed during the

rainfall into different areas including the pond.

Finding 5 states that the farm is a very stable ecosystem with its wide species diversity of 3.09.

AIso it is due to the fact that there are many different species of animals that ensure that the

farm is a very diverse and complex ecosystem. There exists the predator -prey relationship

between many animal species on the farm. A simplified example of the feeding relationships

on the farm can be seen on the food web figUre 6. Top predators are birds.

With reference to finding 6, there is no difference between the carbon cycles in the natural

world and the farm since buming of material is prohibited on these grounds. However there

are the rare wild fires in the wild that cannot be controlled that take place during the dryseason or from contact with lightning during storms. However there are differences in the

system with respect to the nitrogen rycle. The farm is also used to teach students about

farming and legume crops ( peas/Beans/ soybeans) draw nitrogen from the air thus increasing

the normal rate of nitrogen fixation on land. Also other crops are heavily fertilized withnitrogen derived components from industrial fixation. Humans are more than doubling the

rate at which nitrogen is moved from the atmosphere to the land. Also with respect to the

water cycle, the water cycle on the farm does not undergo the seasonal changes that influence

a natural ecosystem. Water is constantly regulated within the ecosystem ie. Regular irrigationof crops and a constant maintainance of the water level in the pond. Here the natural

water table is kept at a constant level as compared to natural systems where the water table

undergoes seasonal level changes.

i

f

CONCI-USION

The population of the Red Tilapia increased from the beginning to the end of the

inveitigation. The species diversity of the pond was found tobe 1.74 which says that this

is not a stable ecosystem due to the face that there is a simple food chain. The species

diversity of the farm was found to be 3.09 which say that the farm is a complex ecosystem

thus making it stable due to its wide variety of trees in the ecosystem. Also a predator-prey

relationship exist among the different animal species in the farm. The biogeochemical

cycles are compared between natural cycles and cycles on the farm. On the farm the carbon

cycle remains the same as the natural cycle. The nitrogen cycle is affected by the use offertilizers added to the soil to enhance crop yields on the school farm. The water cycle on

the farm does not undergo natural changes as in the natural cycles but the water is regulated

throughout the system through regular irrigation of crops and maintenance of the pond's

water level.

XTEC$MMENDATIONS

The Tilapia pellets (Fish food ) ran out and was not replenished immediately for future

investigation the food supply should be readily replenished before the it is used up. A

student should be placed in charge of monitoring the amount of food available for the

fishes so that the organisms are not stressed'

The filter pump had failed due to the water hyacinth roots being sucked in and blocking the

passage way. Any dead plants should be removed to avoid pump failure and damage. The

pump should me constantly monitored and a back up pump should be purchased in the

situation where a pump would fail.

BIBLIOGRAPTIYAuthors- Botkin Daniel B. & Keller Edward A. Environmental science Earth as a living planet

6th EDITION , I published by- John Wiley & sons 2007

Authors- Chapman J.L & MJ Reiss ecology principles and applicants 2nd edition , I

published by Cambridge University Press 2OO6

Authors- Michel Reiss &Jenny Chapman Enivronmental biology, published by- Cambridge

University Press 2004

Authors-Richard T. Wright & BernardJ. Nebel 2OO2Envtuonmental science Toward a

sustanable future 8th EDITION

(HAPTEB 1 THE sTUDYOF ECOLOcY 43