Sky Islands Lab Introduction and Instructions Lab 4

7/23/2019 Sky Islands Lab Introduction and Instructions Lab 4

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BIOL2462 Caribbean Island Ecology

ABIOTIC AND BIOTIC CHARACTERISTICS OF TROICAL S!" ISLANDS

E#ergreen Seasonal Fores$ in Arena Fores$ and %on$ane Fores$ on %orne Ble&

In$rod&c$ion

Sky islands are montane habitats that are surrounded by lowland habitats that are to

greater or lesser extent hostile to the flora and fauna that inhabit the montane habitats.

The specialized flora and fauna of these montane habitats are effectively isolated fromother, similar habitats and thus are subject to island biogeographic processes and to a

certain extent take on characteristics of island populations such as lower species richness

and higher endemism. Much work has been done on the sky archipelagoes in the western

S! and the "ast !frican #ift $alley, where montane habitats are separated by extremelydifferent ecosystems such as deserts and savannas. %n Trinidad and the &esser !ntilles

there are also montane habitats that occur at the tops of volcanoes on the &esser !ntillean

islands and on the peaks of the 'orthern #ange. The main difference between the(aribbean sky islands and those in the S! and !frica is that the (aribbean sky islands

are today surrounded by tropical lowland forest making the arrival and dispersal of taxasuch as birds and other volant animals between sky islands relatively fre)uent comparedto those in the S! and !frica. The flora however shows some island characteristics with

relatively high rates of endemicity in the montane forests of the 'orthern #ange.

Many of the abiotic characteristics that make montane sky islands distinct from thesurrounding ecosystems are those which can only be detected over long periods such as

climate characteristics e.g. temperature range, rainfall *total amount and monthly

averages+, humidity, prevailing wind direction and strength. These can be obtained fromthe literature for a particular ecosystem, however care must be taken that the figures in

the literature are a realistic extrapolation for your site. or example, the climate for the

top of Morne -leu in the 'orthern #ange is not the same as iarco !irport due toaltitudinal differences so the climate as measured at iarco has limited utility in

explaining ecosystem processes on Morne -leu.

/ther abiotic characteristics can best be determined by visiting the ecosystem in )uestionand making observations. "xamples of these types of abiotic characteristics are edaphic

*or soil+ characters such as soil type, permeability, average slope etc0

/ften, abiotic characteristics of an ecosystem can be inferred from the biota in the

ecosystem. lants and animals display morphological adaptations that give a clue to the

abiotic characteristics for an area. or instance, a tall *123 m+, closed canopy forest with

high species diversity indicates sufficient rainfall in all months, ade)uate soil nutrients,well4drained soils, and constantly warm temperatures. !daptations to more stressful

environments such as pneumatophores can indicate the nature of that stress.

The goal of this practical is to introduce you to the montane 5sky island6 ecosystem of

Trinidad7s 'orthern #ange and compare it with a lowland forest site. The objectives of

this practical are to observe, record and compare the abiotic characteristics of a lowlandtropical forest *The !rena orest8 the first stop+ and a montane forest ecosystem *Morne



-leu8 the second stop+ and to observe, record and compare the biotic characteristics of thetwo ecosystems. 9ou will record your observations and discuss the differences between

ecosystem types in a field trip report. lease note the report should be in the form of a

scientific report with an %ntroduction, /bjectives, #esults, and :iscussion. 9ou will beexpected to review the literature for information pertaining to abiotic and biotic

characteristics found in the Seasonal "vergreen *or &owland+ orest and Montane orest

ecosystem in the !rena orest and Morne -leu respectively. lease use the course textsas your literature source but we will give extra marks for other references showing you

have done further reading.

lease restrict your answers to the half a word processed page *font ;<pt= line spacing ;+.

Marks will be deducted for excessively long answers. lease cite the references from

which you obtain the information you state and include a reference list. lease follow the

submission guidelines below.

Field Tri' %e$(odology

pon reaching each field site you will assemble in your bench group of ;3 and proceedinto the forest as directed by your demonstrator and lecturers. 9ou will be taken along a

trail walk for >3 minutes during which your group will make the following observationsat each of the field sites.

;. (ount the number of orb4weaving spiders, butterflies, dragonflies and damselflies,

and &izards seen. 'ote8 we want the numbers of individuals seen not the number

of species.

<. (ount the number of arboreal termite nests greater than about < litres in volume?. !t a point on the walk specified by the lecturer, lay out a <3m tape and gather <3

leaves from understory trees or shrubs over the <3m. "stimate and record the

amount of epiphyll growth on each leaf using the following scale8a. 'one *3@ surface covered+

b. Slight *A B@ surface covered+

c. Moderate *B to <3@ of the surface coveredd. Ceavy *<3 to B3@ of the surface covered+

e. $ery Ceavy *1 B3@ of the surface covered+

2. ind the B tallest trees along your <3m and count and record the number of

epiphytes growing on each.B. !t every <m along your <3m transect, count and record the number of intact

leaves within a Bcm radius of the graduation on the tape. !t each <m graduation

also measure and record the thickness of fragmented leaves and humus.:o not be afraid to ask )uestions. !ppreciate the ecosystems, and have fun.

Analysis o) Da$a

;. (ompare the number of spiders, butterflies, dragonfliesDdamselflies, lizards andarboreal termite nests 1< litres graphically using a histogram. 'o statistical test

re)uired.<. (onstruct a histogram showing the fre)uency of leaves in each class of epiphyll

coverage with separate bars for each of the two sites so they can be compared

graphically. 'o statistical test re)uired.

?. (ompare the mean number of intact leaves and the thickness of the fragmentedleaves and humus between each site using a t4test in each case.



Field Tri' Re'or$

The report should be divided into the following sections8 Introduction *with objectives+,

Methods, Results, Discussion and References. se the following as a guide as to what isto be included in each section of the write up for the lab.

Introduction

!ccording to the literature, how are "vergreen Seasonal *&owland+ orest and Montane

orest different with respect to the three major abiotic characteristics given belowE

*Incl&de a$ leas$ one re)erence+

;. Temperature

<. #ainfall

?. Cumidity

!ccording to the literature, how are evergreen seasonal *lowland+ forest and montane

forest different in terms of the three biotic characteristics belowE *Incl&de a$ leas$ one

re)erence+

;. 'umbers of individuals and species of /rb weaving spiders, butterflies,

dragonfliesDdamselflies, lizards and arboreal termites<. "piphytes and epiphylls?. &eaf litter decomposition rate

Objectives

Fhat are the two main objectives of this practicalE

Methods

-riefly describe the methods used to achieve each objective of this practical.

Results

resent the results as described in the !nalysis of data *above+.

Discussion

"xplain the difference if any between the animal groups observed in The !rena orest

and at Morne -leu. #elate to your reading of the literature.

"xplain the difference if any in the number of intact leaves and thickness of fragmented

leavesDhumus layer between the two sites.

References

(ite the two references you used in this practical. *lease use the (hicago style manual

format which is used by the &ife Sciences discipline. The library,<nd floor, has a handoutyou can use+

S&b,ission



The field trip report for this exercise is an individual effort, please submit your ownreport. se your word processor to answer the )uestions as per the instructions. /nce you

have finished save the file and follow the instructions below for the submission of the

report8

• /nline Turnitin submission *by 2pm on the due date+.

a. or the Turnitin submission we only want to see the 5%ntroduction6 and

5:iscussion6 part of your report so copy and paste the %ntroduction and:iscussion into a new document save it and submit the %ntroG:iscussion

through the turnitin link on the myelearning webpage for -%/&<2><. (lick on

the Turnitin link and follow the instructions. se 5(haracters of Tropicalorests6 as the title of your submission.

b. rint out your Turnitin report. Make sure report has the percentage similarity

score and text of your %ntroG:iscussion with pieces that match the turnitin

database highlighted. %nclude the report with the hardcopy submission.

• Cardcopy Submission *by 2pm on the due date+8

c. or the Cardcopy submission print out the entire file *incl. /bjectives,

Methods, #esults and #eferences+

d. :ownload, print out and include the Turnitin originality report.e. ut your submission in the :rop -ox outside the Hoology /ffice in the 'ew

Fing of the 'at. Sci. -uilding before 2pm on the date for submission. Make

sure submission has8i. your #eport Cardcopy

ii. Turnitin /riginality #eport

Documents

Sky Islands Lab Introduction and Instructions Lab 4