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A LONG TERM ENVIRONMENTAL ENRICHMENT PROGRAMME FOR CAPTIVE
ELEPHANTS – A BEHAVIOURAL STUDY
A STUDY TO DETERMINE THE EFFECT OF RABBIT GRAZING ON CALCAREOUS
GRASSLAND
SIAN THOMAS
PROFESSIONAL TRAINING YEAR
PAIGNTON ZOOLOGICAL GARDENS
COMPLETED AS PART OF BSc BIOLOGY (HONS) DEGREE
UNIVERSITY OF WALES CARDIFF
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CONTENTS
SECTION ONE -Paignton Zoological Gardens
1. History of the Zoo
2. Structure and Function of the Zoo
3. Role of Placement Students
SECTION TWO – A Long Term Environmental Enrichment Programme for Captive Elephants
ABSTRACT
INTRODUCTION
1. Elephants in the Wild
2. Elephants in Captivity
3. Environmental Enrichment
4. Paignton Zoo Elephants
5. History of Project
6. Aims of Project
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MATERIALS AND METHODS
1. Daytime Recordings
2. Night time Recordings
3. Foot and Mouth Recordings
RESULTS
CONCLUSIONS
SECTION THREE – A Study to Determine the Effect of Rabbit Grazing on Calcareous
Grassland
ABSTRACT
INTRODUCTION`
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SECTION TWO – A LONG TERM ENRICHMENT PROGRAMME FOR
CAPTIVE ELEPHANTS
Abstract
Two female elephants, one African (Loxodonta africana) and one Asian (Elephas
maximus), are held at Paignton Zoo Environmental Park. In September 1997 they
were moved from their old enclosure and home of over 20 years, to a larger enclosure.
A long term study of their behaviour has been conducted since just before the move
until the present day.
Both elephants have behaviour patterns of some concern – Duchess (the African)
tends to spend considerable time being totally inactive and Gay (the Asian) exhibits a
typical head-weaving or swaying stereotypy. Shortly after their move to the new
enclosure it was apparent that these behaviours had not improved as greatly as
anticipated and an enrichment programme was initiated. This has evolved in
complexity over the years and has resulted in a steady decline of the concerning
behaviours along with an increase in active and investigative behaviour. The most
recent results indicate that swaying and inactivity have been reduced to negligible
levels during daytime and some progress has also been made at night time when the
animals are locked inside. However, further work is still needed at night time and this
remains a major enrichment challenge.
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Introduction
Restriction of space and a lack of natural stimuli can result in a variety of physical
and psychological problems in captive animals. Elephants in particular can be
affected to a great extent, due to their immense size, strength, intelligence and
complex social structure. Restrictions of captivity can result in certain behaviours
developing that would not normally be performed in a wild environment or at least
not to the extent as they may be captivity. If these behaviours become highly
repetitive they are known as stereotypies and assumed to be an indicator of
suboptimal welfare. Environmental enrichment aims to reduce the occurrence of these
abnormal behaviours by stimulating a wider range of wild-type behaviour patterns.
According to Shepherdson, 1989; Chamove and Moodie, 1990 there are five main
aims:
• Increase behavioural diversity
• Reduce the frequency of abnormal behaviour
• Increase the range or number of normal (i.e. wild) behaviour patterns
• Increase positive utilisation of the environment
• Increase the ability to cope with challenges in a more normal way
If this can be achieved it is thought that the welfare of the animal has been enhanced.
Another advantage of environmental enrichment particularly in a zoo environment is
that it can educate members of the public allowing them to see more natural activities.
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This project was established in 1997 in order to develop a long term enrichment
programme for the two elephants held at Paignton Zoo. Elephants in the wild can
spend up to sixteen hours a day walking in the search for food. This is prevented in
captivity due to the restriction in space and food is usually presented straight to the
animal removing the need to search for it. Therefore large periods of the day become
unoccupied. Many enrichment methods have been formally evaluated for their
effectiveness in reducing abnormal behaviour and increasing foraging, feeding and
exploration behaviour of the elephants. Successful methods have been incorporated
into a programme of enrichment now in its fifth year.
Specific aims
• Reduce the time spent swaying by the Asian Elephant
• Reduce the time spent completely inactive by the African Elephant
• Increase investigative, exploratory, foraging and feeding behaviour of both
elephants
Methods
Subjects
Paignton Zoo holds two female elephants, one African (Loxodonta africana) and one
Asian (Elephas maximus). Duchess, the African is approximately 33 years old and
Gay the Asian roughly a year younger. They arrived together at Paignton from
Longleat Safari Park in 1977. Duchess is the more dominant of the two and exhibits
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more behaviour indicative of having the matriarchal role within this small herd. She is
very food orientated and shows little curiosity in novel items unless they contain food.
Prior to the initiation of the enrichment programme she spent a large proportion of the
day being totally inactive. This time was much greater than has ever been observed in
wild elephants and was therefore of some concern. Gay is much more playful than
Duchess and spends more time interacting with non-food related objects. Prior to
enrichment she spent considerable time performing a typical head weaving or
swaying stereotypy.
Enclosure
In September 1997 the elephants were moved from the enclosure that had been their
home for 20 years to a new exhibit at the other side of the zoo. In contrast to their old
enclosure which was concrete, with a small house and few furnishings their new home
included a large indoor area, a much larger sandy paddock, a wallow and several
scratching posts. In the old enclosure they had frequent contact with the public across
a dry moat. Following the move this contact was no longer possible for their own and
the public’s safety. Human contact is limited to experienced keepers and occasional
protected contact with other staff or special visitors.
Enrichment
Enrichment methods were designed to stimulate species specific behaviour (for
example a small ball feeder designed for monkeys would be pointless for elephants).
They had to be either disposable or extremely strong. Hygiene and safety if items did
break also had to be considered. Individual differences were also taken into account in
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the design of enrichment since Duchess rarely responded to any items not involving
food but Gay did.
A list of enrichments divided into chronological phases is shown in Table 1. The
phases generally correspond to observation periods carried out by successive
sandwich placement students and items in phases 1-4 have been described previously
(Angele 1999, Angele et al. 2001; Gloyns 2000a and b).
Enirchment devices utilised during phase 5 included flour and water logs, kerplunk
and inside feeder logs. The flour and water logs were large logs previously stripped
of bark by the elephabts, covered in flour and water paste and rolled in dry feed
(seeds, flakes etc). The elephants would spend a long time picking the feed off the
logs using their trunks. Once the dry feed was removed, they would then spend long
periods removing the dried flour and water paste in the same way that they would
strip bark off a log. Kerplunk was based on the children’s game of that name and
consisted of a large suspended barrel with fresh bamboo inserted through holes in the
sides. Small amounts of fruit and vegetables were held inside the barrel by the
bamboo and the elephants would remove (and eat) the bamboo until the fruit fell out.
Inside Feeder logs are very large logs with numerous holes drilled into the side.
These holes were then filled with fruit or vegetables and the elephants had to pick it
out using their trunks. The original design was made using much smaller logs that the
elephants could pick up. This resulted in the logs being emptied of food rapidly as the
elephants soon learnt that by throwing the log on the floor all of the food fell out. A
much larger log was then used which they could only roll, not pick up. This allowed
the enrichment device to last a for a much longer period of time as the elephants had
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to manipulate the food using their trunks. Other enrichments added this year are self
explanatory.
Table 1. Implementation phases of an increasing complex enrichment programme for
elephants at Paignton Zoo Environmental Park.
PHASE ENRICHMENT DEVICES
1 • Scatter feed
• Daily food hidden in pipes/boxes and buried
2 • Suspended barrels of dry feed (small holes in bottom of barrel)
• Suspended logs for bark stripping
• Brambles wrapped around branches (provides browse in winter)
3 • Hanging pipe feeders
• Two tyre feeder
• Tyre and chain rattle
• Deep earth container
4 • Scratching post
• Rattles and wind chimes
• Hanging tyre
• New hanging barrels
5 • Giant ice blocks
• Squashed barrel (filled with dry feed)
• Flour and water logs
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• Inside feeder log
• Mini kerplunk
• Bamboo kerplunk
• Hay racks installed at full stretching distance
• Scents
• New log pile
Phase 1: Enrichment designed and implemented by Natalie Barber, 1998
Phase 2: Continuation of enrichment by Natalie Barber
Phase 3: Enrichment designed and implemented by Catalena Angele, 1999
Phase 4: Enrichment designed and implemented by Rosie Gloyns, 2000
Phase 5: Enrichment carried out by myself
NB: Any pre-enrichment data was carried out by Andy Marshall in 1997 immediately
after the elephants moved to the new enclosure.
Observations
Instantaneous focal sampling was used to record the data. Observations were carried
out at minute intervals for half hour periods. For each condition data was collected so
that each hour between the times of 8am and 5pm were covered. No more than two
hours were recorded in any one day and the half hour periods were chosen randomly.
An extensive ethogram has been developed with a number of behavioural codes for
ease of recording. (See Appendix ??) However for the purposes of the enrichment
evaluation certain behaviours were placed into three categories:
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1. Investigative Behaviours (IB) - all investigative and exploratory behaviour
including foraging and feeding are combined.
2. Inactiviy/Swaying (In/Sw) – these are the focal behaviours for the two elephants
(Inactivity for Duchess and Swaying for Gay).
3. Interacting with Enrichment Devices (ED) – this includes any interaction with a
device whether it had been just placed in the enclosure or whether it had been in
place for a long period of time. (i.e. any involvement with the hanging barrels
was noted whether they contained food or not).
As new enrichment methods are found to be successful they are incorporated into the
timetable. To avoid having to remove all enrichment for a time, new phases of
enrichment are tested against the existing timetable rather than against a no-
enrichment baseline. Due to practical difficulties there have been two periods of the
programme when no new enrichment methods were added for several months. These
periods have been termed baseline but they are not baseline in the strict sense since
the existing enrichment items were still being provided. Kruskal-Wallis tests on daily
mean times spent performing the behaviour types of interest have been used to
compare the different phases of the programme.
Results
Since its initiation the enrichment programme has resulted in a steady decrease in
time spent inactive by Duchess (Fig. 1) from approximately 22% to around 4% of the
day (P < 0.01). Inactivity increased to some extent during the two periods (baselines 4
and 5) when no new enrichment was added for several months but did not return to
the levels seen before the programme started.
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Fig. 1 Mean daily time spent on investigative and foraging behaviour and inactive by
the African elephant Duchess during increasingly complex phases of an enrichment
programme. Error bars are standard error.
Enrichment has also resulted in a dramatic decline in time spent swaying by Gay
during the day (Fig. 2) from 24% to less than 1% (P < 0.01). During baseline 4 and 5
when no new enrichment was added this figure did rise slightly but to nowhere near
the levels observed initially. Swaying by Gay during the day is now only observed to
happen when the gate between the outside and inside enclosures are locked preventing
her from choosing where she wants to be. This appears to cause either frustration or
anxiety and usually results in swaying in front of the gate.
0
10
20
30
40
50
60
Pre-en
rich
Phase
1
Phase
2
Phase
3
Baseli
ne 4
Phase
4
Baseli
ne 5
Phase
5
% T
ime
Interactive Behaviours Inactivity
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Foraging and exploratory behaviours do not appear to be greatly affected by
enrichment but these figures do not include and interactions with the enrichment
devices themselves. These times are shown in figs. 3 and 4 for the baseline 5 and
phase 5 (datasets for 2001) and it can be seen that they are quite substantial, in Phase
5 over 30% for Duchess (fig. 3) and over 40% for Gay (fig. 4). Total foraging and
exploration including interacting with enrichment has therefore steadily increased
throughout the programme.
Fig. 2 Mean daily time spent on investigative and foraging behaviour and swaying by
the Asian elephant Gay during increasingly complex phases of an enrichment
programme. Error bars are standard error.
0
10
20
30
40
50
Pre-en
rich
Phase
1
Phase
2
Phase
3
Baseli
ne 4
Phase
4
Baseli
ne 5
Phase
5
% T
ime
Interactive Behaviours Swaying
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Fig. 3. Mean daily time spent performing three behaviour types by an African
elephant, Duchess, during baseline 5 (existing enrichment not changed for several
months) and Phase 5 (new enrichments added) of an enrichment programme
Fig. 4. Mean daily time spent performing three behaviour types by an Asian elephant,
Gay, during baseline 5 (existing enrichment not changed for several months) and
Phase 5 (new enrichments added) of an enrichment programme
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
Investigative Behviours Inactivity Enrichment Device
Behaviour Group
Perc
enta
ge T
ime
Baseline Treatment
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
Investigative Behviours Swaying Enrichment Device
Behaviour Group
Perc
enta
ge T
ime
Baseline Treatment
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FOOT AND MOUTH DISEASE
During the foot and mouth crisis the elephants were put into quarantine for a number
of weeks. At one point they were actually locked in the inside enclosure and had no
physical contact with anyone, including the keepers. This appears to have had
negative affects on the behaviour of both animals. Gay appeared to sway for most of
the day and Duchess became more impatient and aggressive. At this time only
essential staff only were allowed into the zoo and no formal behavioural observation
was performed. This strict quarantine was discontinued after a short time due to these
behavioural problems and the elephants were again allowed outside. However for
several more weeks no enrichment items were allowed to be placed in the enclosure
and data was collected during this period. This has allowed us to generate a true return
to baseline pre-enrichment conditions.
Night time enrichment
Although we have managed to reduce Gay’s swaying to a very small amount during
the day it was thought there may still be a problem at night. Therefore data has been
collected at night to determine the extent of the problem and an enrichment
programme has been established to reduce her swaying at this time. Night time
baseline data indicate that there is little cause for concern for Duchess (fig. 5), she
spends much of the night asleep or foraging for and eating hay. However Gay spends
considerable time at night swaying (fig. 6). This tends to occur in the first two hours
after the keepers leave and again for an hour or so before the arrive back in the
morning. Gay also sways whenever Duchess lies down to sleep. Enirchment methods
have been instigated to reduce swaying at the beginning and end of the night but to
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date we have not found a solution to swaying when Duchess lies down. Data for the
effects of night enrichment is currently being analysed.
Fig. 5 Proportion of time spent performing various behaviours by an African
elephant Duchess during the night.
Fig. 6 Proportion of time spent performing various behaviours by an Asian elephant
Gay during the night.
EatingHayForaging
Sleeping
Standing
Other
Eating hayForagingSleepingSwayingOther
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Conclusions
• Enrichment does work, even for elephants. Swaying and inactivity have been
reduced to minimal levels during the daytime indicating an improvement in
welfare of both animals
• More night time enrichment is needed to reduce swaying by the Asian elephant.
• Habituation to existing enrichment is a problem and new items are continually
needed to maintain stimulation
References
Angele, C. 1999. Assessing the Effectiveness of Environmental Enrichment for
Elephants at Paignton Zoo – A Behavioural Study. Professional Training Report.
School of Biological Sciences, Cardiff University.
Angele C. Barber N. & Plowman A.B. 2001. Elephant enrichment at Paignton Zoo.
Proceedings of the 4th International Conference on Environmental Enrichment,
Edinburgh 1999. In press
Chamove & Moodie 1990. Are alarming events good for captive monkeys?
Applied Animal Behaviour Science 27: 169-176.
Gloyns, R. 2000a. Environmental Enrichment for Elephants at Paignton Zoo - A
Behavioural Study. Professional Training Report, School of Biological Sciences,
Cardiff University.
Gloyns, R. 2000b. Long-term enrichment for captive elephants. Proceedings of the
2nd Annual Symposium on Zoo Research. Ed. A. B. Plowman. Federation of
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Zoological Gardens of Great Britain and Ireland/Paignton Zoo Environmental Park.
Pp 69-71.
Shepherdson, D. 1989. Improving animal lives in captivity through environmental
enrichment. Euroniche Conference Proceedings. Eds F. Dolins and G. Mason
Humane Education Centre, London. Pp 91-102.
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An Investigation to Determine the Effects of Rabbit Grazing on an Area of
Calcareous Grassland
Introduction
In low rainfall areas of the world, grasslands are a common feature and one of the
most widespread vegetation types. However, these grasslands are rapidly reducing.
This is mainly due to the influence of man or where grazing is absent, natural
succession to scrub. This loss is particularly great for calcareous grasslands.(Duffey,
1974).
Grassland communities in Britain can be classified into three categories:
1. Calcareous Grasslands
2. Neutral Grasslands
3. Acidic Grasslands
Calcareous grasslands are formed in regions of high calcium carbonate. The main
types of limestones that they occur on are:
1. Cretaceous Chalk
2. Oolitic (Jurassic) Limestone
3. Carboniferous or Mountain Limestone
4. Magnesium Rich Limestone
(Duffey, 1974)
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Grazing animals are common throughout Britain and have major effects on plant
communities. The Normans introduced the European Rabbit (Oryctolagus cuniculus)
to Britain in the twelfth centuary from the Mediterranean. Originally they were kept
and bred simply for fur and meat. Today they can be found in a variety of habitats
across Britain but prefer areas that allow easy burrowing and an accessible food
supply. The diet consists of a range of plants including grasses, cereal crops, root
vegetables and young shoots of meadow plants. (Gorman, M.L.).
In the middle of the nineteenth century numbers started to increase dramatically until
they began to be considered as agricultural pests. The breeding season is mainly from
January to August, starting later in the North of Britain. Healthy females can produce
one litter of 3-7 young per month during the season. This therefore means that a large
number of rabbits can be born in a year. The rapid increase was also due to a large
number of hedgerows that were planted due to new enclosure acts. This provided
ideal habitats for the rabbits as burrowing improved due to loosened soil and provided
shelter. Advances in agricultural technology also meant an improvement in the
production of cereal crops increasing the food supply available to the rabbits.
Another factor that played a role in the increase in numbers of the rabbits was that a
large number of their natural predators were killed by the formation of hunting
estates. (Gorman, M.L.).
Myxomatosis occurred in Britain in the 1950s which was very successful in reducing
the numbers. However, this rapid decline in numbers caused major changes in natural
vegetation as the amount of grazing was dramatically reduced (Bhadresa, R. 1987
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cited Sheail, 1971) This allowed natural succession of grasslands and other areas to
scrubland affecting the species composition and removing rare species due to
competition.
After the initial epidemic of myxomatosis the national population of rabbits started to
increase gradually again and numbers at present are high once again.
Grazing may eliminate species from an area in two ways:
1. Outright removal of all plants
2. Lowering the density of plants to such a level that any individuals that remain
exist in such a low distribution that it is impossible to sustain a self-replacing
population hence the removal of the species.
(Silvertown, J.W., 1982 cited Carter and Prince, 1981)
Vegetation may be defined as ‘an assemblage of plants growing together in a
particular location and may be characterised either by its component species or by the
combination of structural and functional characters’. (Goldsmith et al, 1986)
There are different methods of studying vegetation. Structural or physiognomic
methods do not require individual species to be identified. Zoologists therefore often
prefer these methods as they are more meaningful for small-scale studies and for
habitat descriptions. For studies such as this one, methods based on species
composition or floristics are more valuable as they are more detailed and botanical in
nature.
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There are different measures based on floristics which can be classified into two
categories:
1. DESTRUCTIVE MEASURES
Fresh weight and dry weight are the two most commonly used measures. Fresh
weight has the disadvantage that moisture content varies within plants which
would affect the results. These measures however are not being used in this
project due to the fact that there are many species on the grassland that are
considered rare.
2. NON-DESTRUCTIVE MEASURES
Site Description
The area of grassland studied is situated within an area of land known as Clennon
Gorge. Clennon Gorge is approximately 60acres and stretches down to the sea
between Paignton and Goodrington in South Devon. The land on which the grassland
is situated is owned by Paignton Zoo but access to the public is denied.
The site is predominately on carboniferous limestone which forms a plateau on the
eastern side of the valley. The grassland is position on this plateau and shows the
characteristic flora of calcareous grassland.
The grassland and surrounding woodland provide a suitable habitat for rabbits and
other small mammals. In 19?? four small exclosures were established. The
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exclosures are generally rectangular in shape constructed from wire mesh
approximately 50cm high. For the purpose of this study only two of the four
exlosures will be studied. One of the exclosures was deemed to be situated too far
into the woodland to be statistically comparable as other factors would be influencing
the diversity and the other – the largest of the four is situated in the area that is
virtually entirely scrub land. It is also surrounded by trees which creates a large
amount of shade affecting the microclimate and making it more humid. This
therefore provides different conditions and therefore different species would thrive.
Due to this and the fact that this exclosure is so much larger than the others it was
decided to dismiss this exclosure. This left two exclosures suitable for comparison.
Exclosure One is situated on the lower part of the grassland whereas Exclosure 2 is
situated on the higher level.
Exclosure One
Exclosure Two
4.90m
5.30m
5.00m
5.05m
4.95m
4.95m 4.60m
4.65m
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Due to the variation in size and shape of the exclosures it was decided that a 4m x 4m
plot should be taped off inside the exclosures. Not only does this allow for accurate
statistical analysis it also reduces any edge effects that may occur.
Each exclosure however is slightly different. Exclosure one only managed to partially
exclude the rabbits. Evidence of rabbit dropping was discovered within the exclosure
and two holes were found within the fencing. These holes were repaired and
therefore this exclosure is deemed as a partial exclusion zone. Exclosure one is also
in the shade until around 11.30am whereas Emilly is in direct sunlight for the entire
day.
Aims
To determine:
1. Is there a difference in species composition in different areas of the grassland?
(i) open grassland
(ii) rabbit exclosures
2. Is there a particular species of plant that is preferred by the rabbits?
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3. Is there a particular species of plant that is dominant due to the effect of the
grazing (ie is there a plant that thrives due to the fact that other species have been
removed by the rabbits)?
4. Are there any other factors apart from rabbit grazing that may affect the
composition?
5. Does the height of plants vary between the grazed area and the exclosures?
6. Are there any differences between the two exclosures?
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Method
Grazed Area
• The presence of species in 50cm x 50cm quadrats located at 0.5m intervals along
2 parallel straight lines.
• At least 100 quadrats to be recorded. (50 on each transect)
Exclosures
• Tape off a 4mx 4m so that all three sampling areas are the same size and shape
and to reduce edge effects.
• Random quadrat sampling so that at least 50 quadrats are recorded.
Within each quadrat a number of factors will be assessed:
• Species present
• Maximum height of vegetation
• Species diversity (ie a pin will be placed in the centre of the quadrat and any
species touching that pin will be recorded as well as the heights of those species).
Within each exclosure other factors will also be recorded:
• Depth of Soil
• pH
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