Download Section 1 re-write for 2001

BIOLOGY 2.5 ECOLOGY
AS 90461
TITLE:
Describe concepts and processes relating to ecology.
EXPLANATORY NOTES:
Concepts and processes relating to Ecology will be selected from: biodiversity, adaptations,
succession, zonation, stratification, distribution, competition, predation, parasitism, mutualism,
density, habitat, antibiosis, adaptations.
OBJECTIVES
Classification:
1.
State the names of the 5 different kingdoms and general characteristics of each with examples.
(a) State terms used in the classification system from kingdom to species.
(b) Classify organisms using the binomial classification system.
2.
Practice using keys.
Ecosystems:
3.
(a) Define Ecology
(b) Define and give an example for: habitat, adaptations (structural, behavioural and
physiological) and ecological niche.
4.
State Gause's Principle.
5.
Define environment, abiotic and biotic factors, intraspecific competition and interspecific
competition.
6.
State the Law of Tolerance and distinguish between zones of physiological stress, optimum
range and limit of tolerance.
7.
State Leibig's Law of the Minimum.
8.
Define limiting factor.
Populations:
9.
Define population, density, distribution.
10. State random sampling procedures: quadrats and transects.
11. Define population regulation.
Communities:
12. Define and give an example of each of the following: community, commensalism, mutualism,
parasitism, antibiosis.
13. Define zonation, stratification, succession, pioneer species, climax community.
14. Interpret predator - prey interactions.
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SPECIAL CHARACTERISTICS OF NEW ZEALAND
FLORA AND FAUNA
NB:
Endemic:
Native to, and found only in, New Zealand
Indigenous: Native to New Zealand but can be found elsewhere.
Biodiversity: The variety of organisms that exist in an area.
NZ FLORA
1.
("seed with a foot") Forest - among most ancient forests in the world. Not changed
much since NZ was part of Gondwana, 190 million years ago. Podocarps are an ancient
Gymnosperm group. NZ examples are: rimu, kahikatea, totara.
2.
About 80% of all native vascular plants (ferns, conifers, flowering plants) are endemic (found
only in NZ)
3.
Most common flower colour of NZ alpine plants is white or pale yellow. Adaptation to attract
flies, beetles and moths, as NZ has few butterflies and long-tongued bees. Many flowers are
small and inconspicuous, but have exposed nectaries and are highly scented at night (attract
moths).
4.
Certain plant genera have spread more extensively in NZ than elsewhere in the world. eg.
Hebe and Coprosma (have evolved to fill available niches), each with more than 35 species in
NZ. Alpine vegetation is still evolving (Southern Alps are only 5 million years old).
5.
Very few NZ plant species produce toxins and they are therefore palatable to introduced
mammals.
6.
Many plants have juvenile forms - which look quite different from the adults eg. lancewood.
7.
Many shrubs and juvenile forms are divaricating (filiramulate) - dense, interlacing network of
short, wiry twigs bearing very small leaves. Possibly protection against wind, frost and
desiccation, eg. coprosma, prostrate kowhai.
8.
Few deciduous or annual plants.
9.
High percentage of dioecious plants - separate male and female plants, eg. coprosma.
10.
Many plants produce heavy crops of small but colourful, fleshy fruit - bird dispersal, eg.
kahikatea, coprosma and rimu.
PODOCARP
NZ FAUNA
In the absence of native, ground-dwelling mammals, because of NZ's isolation from the rest of the
world, our fauna has many unusual species. Many are the only representatives of their particular
group.
1. Birds - large size and loss of flight - therefore ground-dwellers, eg. kiwi, weka.
Kiwi: lay the largest egg in proportion to size of parent, of any bird.
Kakapo: only member of its genus - largest parrot in the world.
Moa: one of the largest birds ever known in the world. Grazers - 20 species were found in
New Zealand.
Sea birds: over half NZ native birds.
 Vocalisation is important - distinguishing song to attract mates, and defend territory (colour not as
important).
2
2. Insects
- well camouflaged.
- many wingless, eg. cockroaches, earwigs, beetles, stick insects, wetas (giant weta - largest
insect of its kind in the world, 100 mm in length, 60 g. Endemic.)
- very few butterflies - about 16 species.
- 1500 species of moth - pollinators
- 250 000 species of beetles - pollinators
3. Spiders
- of the 10 orders only 4 are found in NZ. Hunting spiders such as the Avondale spider (size
of fist) are very large.
4. Snails
- large (up to 9 cm across). NZ has largest variety of primitive, carnivorous land snails in the
world.
5. Peripatus
- (photo page 368 Bio Science) - small caterpillar-like ("velvet worm") - very ancient.
Evolutionary link between annelid worms and insects.
6. Earthworms
- biggest in NZ is 1.4 m long and found on Little Barrier Island.
7. Frogs
- rare NZ native frog Leiopelma has no free-living tadpole stage. Most primitive living frog
known. Pounces on food rather than flicking its tongue out - very small.
8. Tuatara
- relatives lived over 200 million years ago, all dying out 60 - 70 million years ago.
9. Mammals
- only 2 species of bats - small, rare and nocturnal.
REASONS FOR EVOLUTION OF SPECIAL CHARACTERISTICS
1.
2.
3.
4.
5.
6.
7.
8.
Isolation
Wide latitudinal span of the 3 main islands.
Lack of mammals (except 2 bats) and therefore absence of predators and competition.
Distinct fauna and flora - many being endemic (found nowhere else in the world)
Flightless forms filling ecological equivalent niches to mammals in other parts of the world.
eg. moa equivalent to kangaroo or zebra.
Immigration by way of sea and wind - many organisms from Australia.
Isolation in glaciations has led to evolution of new species.
Maori and European came with mammalian predators and competitors, grasses and weeds
were introduced, fire, and habitat destruction has led to many organisms becoming extinct, eg.
huia, moa, Haast eagle, and endangered, eg. kokako, kakapo, takahe.
Videos
 # 231 Land of the Kiwi
 #156 - David Attenborough's New Zealand Birds
3
BIOLOGY -
The Study of Living organisms
5-KINGDOM CLASSIFICATION
All Living Things
on Earth
Kingdom
Prokaryota
 single cell
 no nuclear
membrane
 no cell
organelles
eg. bacteria and
blue-green algae
Kingdom
Protista
 single celled
 nuclear
membrane
eg. algae, amoeba,
paramecium
Kingdom
Fungi
 single celled and
multicellular
 no chlorophyll
 produce spores
eg. yeast, mushroom,
tinea
Kingdom
Plantae
 multicellular
 contain
chlorophyll
 photosynthesise
eg. mosses, ferns,
conifers, flowering
plants
Kingdom
Animalia
 multicellular
 consumers
Contains 9 phyla
eg. chordata
Note: (Page 5 Life Science)
Plants are autotrophic, meaning: _______________________________________________
__________________________________________________________________________
Animals are heterotrophic, meaning: ____________________________________________
__________________________________________________________________________
Q? Are Fungi autotrophic or heterotrophic? _________________________________________
Explain your answer: ________________________________________________________
__________________________________________________________________________
Activities
See Videos:
#62
Five Kingdom Classification (20 minutes)
or
#132 Classification and worksheet (Bringing Order to Diversity)
 Powerpoint programme on Animal Classification
 Round Robin of Specimens, suitcase of specimens.
 Cut and paste organisms into phyla and classes.
 Make a lolly key.
4
THE THEORY OF CLASSIFICATION
(Read Pages 11 - 13 in your Text)
Taxonomy is the science of the classification of living things.
The Swedish naturalist Carolus Linnaeus (1707 - 1778) introduced a system of naming organisms
which helped humans to organise into groups all the knowledge that had been gathered.
Linnaeus introduced the binomial system for naming organisms. Each organism has two parts to its
name, which is hence known as a binomial name. The first part indicates the genus to which the
organism belongs and the second part is its species name. The name for humans is Homo sapiens.
The generic name is written with a capital letter; the species name with a lower case letter. The
binomial name is often written italics or it may be underlined. Linnaeus also introduced other higher
categories which we still use today - order, class and kingdom. Two more taxonomic categories
have been added since Linnaeus' time - family and phylum.
The taxonomic categories are as follows:
 Species (plural: same) - a group of organisms which can successfully interbreed in nature and
produce fertile offspring.
 Genus (plural: genera) - consists of similar species grouped together
 Family - consists of similar genera grouped together
 Order - consists of similar families grouped together
 Class - consists of similar orders grouped together
 Phylum (plural: phyla) - consists of similar classes grouped together
 Kingdom - consists of related phyla grouped together
There may be further subdivisions within the taxon, indicated by the prefix sub, for example subclass.
Taxon
Kingdom
Phylum
Subphylum
Class
Order
Family
Genus
Species
Taxon
Kingdom
Phylum
Class
Subclass
Family
Genus
Species
Animalia (all animals)
Chordata (animals with a dorsal nerve cord)
Vertebrata (animals with a vertebral column)
Mammalia
Carnivora
Canidae
Canis
Canis lupus (wolf)
Canis familiaris (domestic dog)
Plantae (all plants)
Tracheophyta (plants with a vascular system)
Spermatopsida (seed plants)
Angiospermae (flowering plants)
Papilionaceae
Sophora
Sophora tetraptera (kowhai)
Sophora microphylla (kowhai)
5
GETTING KEYED-UP
What do you get if you cross a shark with a snowman?
Professor Percival has collected some animals previously unknown to biologists (or anyone else for that
matter). He has described them and constructed a key for their identification. Use the key to discover what
name he gave to each specimen. The initial letters of their names spell out the answer to the riddle .You may
use the same answer more than once.
KEY
1a. Feet
1b. No feet
2a
6a
2a. Four feet
2b. Less than four feet
3a
8a
3a. Definite head end
3b. No definite head end
4a
Fetidiensis
4a. Head has at least one extension for food gathering
4b. Head has no extension for food gathering
5a.
Slimiensis
5a. Two eyes
5b. Numerous eyes on stalks
Basiliskus
Odorifensis
6a. Spines
6b. No spines
7a.
Excrescia
7a. Spines more than 5mm long
7b. Spines less than 5mm long
Toxicus
Decomposus
8a. Frill-like outgrowths
8b. No frill-like outgrowths
9a.
Regurgitus
9a. Base wider than apex
9b. Apex wider than base
Putrefactus
Ickius
1.
2.
3.
4.
5.
6.
7.
8.
9.
6
ECOLOGY
DEFINITIONS
 Ecology is the study of relationships of organisms with the world around them. (both living and
non-living)
 Habitat - p.22. The habitat of an organism is the place where it lives.
 Adaptations - p.18 These are the special features an organism possesses that enable it to survive.
NOTE: An adaptation is always followed by the word "to" or "for". eg. A cat has fur to keep it
warm.
There are 3 types:
1. Structural adaptations These are ___________________________________________
__________________________________________________________________________
An Example is: _____________________________________________________________
(describe how the example helps survival) _______________________________________
__________________________________________________________________________
2. Physiological adaptations (Also called functional) These are: _________________
__________________________________________________________________________
An Example is: _____________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
3. Behavioural adaptations This is ____________________________________________
__________________________________________________________________________
An Example is: _____________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
Activities:
 Suggested video #28: The Baking Deserts - list the adaptations the organisms have to survive in
this environment.
 # 87 Plant and Animal adaptations
 Computer Room Habitats CD Rom.
7
 Ecological Niche
An ecological niche refers to an organisms way of life (role) and the adaptations it possesses to
survive in the environment. The ecological niche of an organism is determined by 2 main factors:
a) The opportunities provided by the habitat.
b) The adaptations that enable an organism to take advantage of the habitat.
Ecological Niche Examples
Organism
Earthworm
Habitat
moist, well aerated
soil
Role
herbivore, feeding on
dead plant materials
Adaptations (2)
1. Streamlined to move
through soil.
2. Secretes mucus to
prevent dehydration
Shark
Mangrove
(p 26 & 227)
Activity:
- or
-
Video #23
Wild South Mangroves
# 109
Select an organism and describe its ecological niche in detail.
Organism:
(common name)
_________________________
(scientific name)
_________________________
Ecological Niche: ____________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
CO-EXISTENCE - P.20
If two different species lived in the same habitat and occupied the same ecological niche, they would
compete for the same resources such as food, space and shelter. Sooner or later there would not be
enough resources to meet the needs of all of the members of both species. One or other of the species
would die out, move away or alter its requirements ie. change its niche.
Gauses Principle states that - No two species with identical ecological niches can co-exist for very
long.
Do the experiment on page 21 of your text using cabbage tree leaves or Experiment 1
8
EXPERIMENT 1: CO-EXISTENCE AND ECOLOGICAL NICHE
INTRODUCTION
Two herbivorous moth larvae live on flax bushes or cabbage trees in New Zealand. These are the
"notching" caterpillar - notch noctuid, and the "window" caterpillar - window geometer.
The notching caterpillar grows up to 35 mm and is often pinkish with fine black lines. The geometer
caterpillar grows to about 25 mm, is transparent yellow in colour with a central longitudinal dark red
strip. It moves by looping.
Gause's Principle states that "no two species with identical ecological niches can co-exist for long in
the same place".
Aim
To determine whether two similar species exploiting the same plant actually have the same
ecological niche.
Method
1. If possible use living cabbage trees available where measurements can be carried out in situ.
2. Measure the distance (to the nearest 2 mm) from the mid-rib (centre) of a cabbage tree leaf to the
nearest point of the window-shaped hole that the geometer caterpillar makes while feeding (dw).
Repeat for at least 50 windows.
3. Repeat this procedure for the notches (dn).
4. Avoid taking measurements from
the tip and the bottom of the leaf.
WRITTEN REQUIREMENT:
1.
Results
a)
Record the two sets of results in the form of tally charts on your own paper.
b)
Plot these results on a graph-histogram. Draw the two graphs in different colours and
include a key.
Caterpillar Distribution on Cabbage Tree Leaves
Frequency of
each caterpillar
Distance from mid-rib (mm)
2.
Discussion
a)
Do the graphs overlap? If so, explain what this overlap mean in the lives of the caterpillars?
b)
Considering Gause's Principle, discuss why these two species of caterpillars still survive
on the same plant.
c)
Given the information you already have about the ecological niche of these caterpillars,
explain how you would discover more information about their ecological niches (2 ideas
needed).
9
ASSIGNMENT ONE
THE ROCK POOL HABITAT
Refer to the information supplied on P27 of Life Science and answer the following questions.
1.
Explain why temperature of rock pools vary much more than sea temperature.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
2.
Pools A and B were near each other and the temperatures were recorded on the same day.
Explain why the temperature in Pool A is increased more than in Pool B.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
3.
Discuss why the temperature of each pool suddenly returned to the same temperature as
the sea.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
4.
Explain why Pool B returned to sea temperature before Pool A.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
5.
Describe how the salinity of a rock pool could cause it to
(a) increase (become more salty) ___________________________________________
_______________________________________________________________________
_______________________________________________________________________
(b) decrease (become less salty) ____________________________________________
_______________________________________________________________________
_______________________________________________________________________
10
6.
Describe the type of pool which would be more susceptible to changes in salinity.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
7.
Describe other abiotic factors that could change in a rock pool when the tide is out.
(Consider effects of photosynthesis and respiration)
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
8.
Describe the general conclusions that you can make about the limits of tolerance of rock
pool organisms.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
11
ENVIRONMENT p.22
An organism's environment consists of abiotic and biotic factors.
Abiotic Factors are physical factors and operate independently of the number of organisms present.
They are caused by non-living things.
Biotic Factors are those caused by living things.
 Complete the table (page 23)
Biotic Factors
Abiotic Factors
In the example below, circle the biotic factors.
COMPETITION p.17
When a number of organisms use a common resource and it is in limited supply, competition will
occur. This can cause a decrease in population numbers or migration.
eg. plants may compete for
________________________________________________________
__________________________________________________________________________
animals may compete for
________________________________________________________
__________________________________________________________________________
12
Intraspecific competition is _________________________________________________________
___________________________________________________________________________
and is usually a _________________________ intense form of competition.
Interspecific competition is _________________________________________________________
___________________________________________________________________________
Competition can be beneficial in controlling population numbers and in ensuring that only the
organisms best adapted to the environment survive and reproduce.
TOLERANCE p.24-26
Tolerance is an organism's ability to survive changes in environmental conditions. An organism
usually has a range of conditions in which it functions best. This is called its optimum range.
When conditions are not ideal, the organism is likely to suffer physiological stress. Body functions
usually show warning signs. When the limit of tolerance is reached, the organism will no longer be
able to survive. Tolerance can affect the distribution of a species.
eg. Mangroves (pg 26 & 227) can grow _______________________________________________
_______________________________________________________________________________
and cannot tolerate ________________________________________________________________
________________________________________________________________________________
What limits the lower level of a Beech forest? ___________________________________________
________________________________________________________________________________
Example: The effect of temperature on houseflies - sketch the graph on page 24. Include labels.
13
LIEBIG'S LAW OF THE MINIMUM - p.25
The functioning of an organism is limited by the essential environmental factor that is present in the
least favourable amount.
eg. For hundreds of years, a disease called scurvy disabled sailors on long voyages. This disorder,
which could not be alleviated by an increased portion of salt pork or weevily ships biscuits, was
eventually cured by the use of citrus fruit.
The absence of Vitamin C, it is now known, was the limiting factor in these men's diet.
Give another example to illustrate this law: ______________________________________________
_________________________________________________________________________________
GORSE WEEVIL (Apion ulicis)
Collect gorse weevils from gorse bushes using a container with a lid and a ruler.
The Life Cycle:2 weeks later, pods
ripe and adult larvae
flung out
ADULT
feed on gorse
EGG
laid in young pods
female bores hole in pod
with snout and lays eggs
PUPA
LARVA
hatch in 4 weeks and attach
to grown seeds and feed
on seeds. 6 - 8 weeks
fully grown and then pupate
On your Own Paper:1.
Describe the ecological niche of the gorse weevil.
Include its
a) role (job)
b) adaptations
c) habitat
2.
Draw a food chain which includes the gorse weevil.
3.
Draw a food web which includes the gorse weevil.
4.
Look at a gorse weevil under a stereo microscope. Draw it:Good biological drawings have the following features:
 Large, done with a sharp pencil in 2D
 clear, single lines ie. no sketching or shading.
 in proportion and correct perspective ie. accurate
 correct detail ie. correct number of legs, from right place, segmentation
14
POPULATIONS - Pages 28-39
A population is defined as:
__________________________________________________________________
__________________________________________________________________
Individuals are described by their age, sex etc. Populations are described in terms of density,
distribution, natality and mortality rates, survivorship, age structure and growth patterns.
Density of population (page 30)
The density of a population is _________________________________________________________
___________________________________________________________________________
Distribution of population (page 30)
The way that individuals are spread through an area can vary. They can be evenly spread eg.
_____________________________ or _____________________________ or they can be in clumps
or groups of high density with very few between eg. ________________________________________
Organisms' distribution is related to abiotic and biotic factors.
This variation in distribution can make the assessing of total population difficult. Generally you cannot
find each individual to add them up and it would also be extremely time consuming in most cases.
Sampling techniques are therefore used to assess total population or population density. Two
important factors are involved in sampling.
(page 36)
a) Number of samples: This is decided by ______________________________________________
______________________________________________________________________________
b) Position of samples: The positions must be chosen at random otherwise ___________________
______________________________________________________________________________
______________________________________________________________________________
Sampling Techniques
Quadrats: This involves using a sample area, the size chosen is the most critical part. Choose a
suitable quadrat size for assessing the following populations:a) Ants in a field
________________________________________
b) Pine trees in a forest
________________________________________
c) Grass plants on a farm
________________________________________
d) Periwinkles on a rocky shore ________________________________________
Transects: These are lines marked at regular points. They are laid down and the organisms at each
point noted. These are especially useful for distributions that change over a distance eg. up a mountain
or from high tide to low tide on a beach. Quadrats and transects can be combined.
15
Population Growth:
Populations generally grow in a typical way as they colonise a new area.
Copy diagram 4.7 on page 32.
Explain the following parts of the graph:
Beginning phase: __________________________________________________________________
_________________________________________________________________________________
Exponential (fast) phase: _____________________________________________________________
_________________________________________________________________________________
Slowing phase: _____________________________________________________________________
_________________________________________________________________________________
Equilibrium phase: __________________________________________________________________
_________________________________________________________________________________
This shape of graph is called a sigmoid or "S" shaped curve. If you calculate the rate of growth and
plot this on a graph against time you get a bell shaped curve. Copy diagram 4.8 on page 32.
16
Regulation of Populations
Populations in natural habitats do not always grow in the same way as in the theoretical situation.
There are often things (factors) that affect the rate of growth. (Copy diagram 4.10 on page 34)
Regulating Factors regulate populations and may limit the areas that a population can survive in.
a) Environmental Factors: eg. soil type, salinity. Many aspects of the environment affect living
things and they can only live within a certain tolerance range.
b) Competition: Interspecific competition is between members of different species for a limited
resource. This reduces the growth rate of populations involved. They might be competing for food,
nest sites, water, sunlight etc. Intraspecific competition is between members of the same species.
Competition of this type may be reduced by individual members of a species establishing and
defending a territory within its home range. This spaces out nesting sites, food sources and potential
mates (see page 35)
c) Exploitation. Where one species exploits another as food. This controls the level of population.
d) Disease. Spread of disease can reduce populations markedly. The advantage of variation within a
species is that often not all members are adversely affected.
e) Overcrowding. If population density gets too high, then the level of fighting and stress increases.
The level of reproduction can become reduced and emigration may increase.
f)
Humans. Control population by:
i) over-hunting
ii) destroying habitats
iii) overuse of pesticides eg. DDT
iv) toxic wastes from manufacturing
17
EXPERIMENT 4: FACTORS LIMITING POPULATIONS
INTRODUCTION
The growth of natural populations is normally limited by food supply and other factors.
Gathering data on natural populations is always difficult. It is assumed that the actual density of New
Zealand aphids was always proportional to the number caught.
Aim:
To study the growth of a natural population of aphids on roses.
WRITTEN REQUIREMENT
Results
Table of Aphid Density on Roses
Month
Average No. of Aphids
caught per night
Month
Average No. of Aphids
caught per night
April
May
June
July
August
September
2
5
7
5
1
8
October
November
December
January
February
March
52
97
94
50
9
6
 Graph these results beginning with the month of April on the X-axis.
18
19
DISCUSSION (Answer below)
1.
During which months are there the greatest increases in population numbers? Suggest why this
might have occurred.
2.
List 5 factors that might have caused the sudden decrease in the population during January and
February.
3.
This population could be described as an open population. What is meant by this? What effect
would this have on population numbers?
4.
This type of growth also illustrates what happens when a population reaches its upper limit and
crashes. This is the seasonal boom-bust curve (or J-shaped curve) that occurs in many insects and
algal blooms.
population
size
Time
20
COMMUNITIES - Pages 40 - 53
A Community is defined as
_______________________________________________
_______________________________________________________________________
Special Inter-Relationships within a Community.
1. Commensalism - A relationship where one benefits and the
other is unharmed.
Two examples are:
2. Mutualism [sometimes called symbiosis] - This is a relationship
where two different organisms live together for their mutual
benefit.
3. Exploitation - One organism benefits and the other is harmed.
A successful parasite does not kill its host (food source)
4. Antibiosis - One organism is inhibited while the other is
unaffected. eg. penicillin and bacteria, where bacterial growth is
inhibited. NB. Penicillium is a fungus which produces the
antibiotic penicillin.
21
Summary Copy the chart on page 49. Add Competition and
Antibiosis to the chart.
Patterns within a Community
Each species has a different tolerance to any environmental factor. A gradually changing factor called
a gradient causes patterns in the distribution of species. The main advantage of these is to reduce
competition.
1.
ZONATION (page 43)
Zonation is _________________________________________________
____________________________________________________________________________
a) Rocky Shore - the main factor causing zonation here is _________________________.
Species in different zones have different adaptive features which enable them to live successfully
in a particular zone. The main zones are...
i)
__________________________________________________
ii) __________________________________________________
b) High Mountains - the zones there are caused by ______________________________.
Draw the diagram of a South Island Mountain (page 43)
22
c) Each side of a Stream - Different species of plants appear as moisture reduces away from
the stream.
23
2.
STRATIFICATION - easily seen in a forest community.
This is defined as _____________________
______________________________________________________________________________
The six main layers in a forest are: ______________________________________________________
__________________________________________________________________________________
Each layer offers a range of habitats and niches and has a characteristic set of animals. As light intensity
decreases, temperature is reduced and humidity increases. Maximum sunlight in the canopy results in
high exposure and so water loss is high. Each layer is adapted to different light intensities, temperature
and humidity.
3.
SUCCESSION (pages 44 & 45)
Succession is defined as ________________________________________________________
____________________________________________________________________________
Pioneer species: early coloniser during the establishment phase of a community on bare rock.
eg. lichen, grasses.
A climax community is the stable, mature results of succession. Species composition remains stable.
Copy the example to show typical NZ order of succession.
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
Activities:
 Trials of Life. Video #85 Living together
 Deer & Wolf Experiment on Predator/Prey Relationships. (Experiment 5)
EXPERIMENT 5: POPULATION MANAGEMENT
INTRODUCTION
A count of deer population on an island forest reserve (of about 500 sq km) showed a population of
2000 animals in 1960. The island had vegetation suitable for deer, but the food supply was limited. It
was feared that over-grazing might result in mass starvation. Since the area was too remote to employ
hunters, it was decided to bring in natural predators to control the deer population, and in 1961 ten
wolves were flown in to the island.
Aim:
To understand some relationships between predators and their prey, and to relate this to
population control.
24
WRITTEN REQUIREMENT
1.
Results
Table of Predator-Prey Populations
Year
Wolf
Deer
Deer
Population Population Offspring
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
10
12
16
22
28
24
21
18
19
19
2000
2300
2500
2360
2244
2094
1968
1916
1952
1972
800
920
1000
944
996
836
788
766
780
790
Predation Starvation
400
480
640
880
1120
960
840
720
760
760
100
240
500
180
26
2
0
0
0
0
 Using the data presented, plot a graph to show the fluctuations in deer and wolf populations during
the 9-year study.
Deer
Wolf
Time
2.
a)
Discussion
Explain why you think the wolf population declined after 1965.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
b)
In which year was deer starvation the greatest? Explain why you think so many deer died?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
c)
Explain what you think might have happened to the deer population if hunters had been
employed to kill half the wolf population in 1964? (2 ideas needed)
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
d)
Is wolf predation a regulating factor on the reserve? Describe 2 other factors that might be
involved in controlling the deer population?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
25
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ASSIGNMENT 4 - Relationships
1.
[15 Marks]
Describe the type of relationship of each of the following:a) birds picking ticks off cattle.
____________________________________
b) remora attaching themselves to sharks.
______________________________
c) small crabs living inside live mussel shells. ______________________________
2.
d) tape worms living inside a dog.
______________________________
e) mice living off human food wastes.
______________________________ [5]
Explain what environmental factor changes gradually in the following communities?
a) from the centre of a walking track into the bush. ___________________________
b) from the surface of the sea to deep ocean. _______________________________ [2]
3.
Copy and complete the following table:Species A
species B
+
+
─
0
0
─
─
─
Relationship
[4]
4.
Each of the following is an example of a biological pattern, what are they?
a) Barnacles found in a band between high and low tides on a rocky shore. ______________
b) The growth of Lupins between some Marram grass, over time
resulting in the Marram grass dying off.
_______________________________
c) Tall grass shading small moss plants between them. ______________________________
d) Mountain Beech being found at the top of the
bush line on mountains.
27
_____________________________ [4]
Use the following information to answer questions 5 & 6
Nitrogen Cycle
Nitrogen built into
plant protein
(11)
N2 pool in air (10)
(3)
Animal
Protein
(1)
Dead plant
and animal
material
(1)
(9)
(4)
(5)
NO3-
(7)
(6)
NH4+
(9)
NO2-
5.
Where do the following processes occur? (Give number)
a) Denitrification
d) Nitrification
g) Ammonification
6.
b) digestion
e) Excretion
h) Nitrogen fixation
c) Protein synthesis
f) Death
The following organisms will be active at... (give correct number)
a) Saprophytes
d) Nitrification
b) Rhizobia
e) Dentrificans
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c) Nitrobacter