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UNIVERSITY OF TECHNOLOGY, JAMAICA
FACULTY OF SCIENCE & SPORT
ENVIRONMENTAL STUDIES MODULE OUTLINE (SEM II – 2010/11)
Lecturers/Tutors: Raymond Martin, Nikki Bramwell, Damian Nesbeth
Nadia Watson-Spence, Debbie Devonish
Dates
Topics
17/01
Introduction: The state of our environment; cornucopianism vs
environmentalism; natural resources; renewable and non-renewable
resources; pollution; degradable and non-degradable pollutants;
conservation; sustainability ; environmental law; role of NEPA; EMS
Chapters 1- 3
24/01
Ecology:
Definition of ecology; biotic and abiotic environment; biological
organisation of the environment- population, community, ecosystem,
biosphere; physical organisation of the environment – atmosphere,
hydrosphere, lithosphere, biomes, and ecosphere.
Ecosystems and energy flow: Thermodynamics, photosynthesis,
respiration; food chains, food webs, trophic levels
Chapter 4
31/01
Biogeochemical cycles: carbon, nitrogen, phosphorus, sulphur, water.
Chapter 6
07/02
Ecosystems and Living Organisms: Interactions among living organisms;
Predation – predatory strategies, prey strategies; Symbiosis - parasitism,
mutualism, commensalism; Competition – specialisation, habitat, niche;
Evolution; Succession – primary, secondary, fire, aquatic; climax community.
14/02
Biomes: coral reefs, tropical rain forests, wetlands, mangroves
Chapters 5, 7
Biodiversity: – species, genetic, ecosystem; characteristics and examples
of endangered and extinct species; Conservation biology
Chapter 5, 16
14/02
Graded Class Assignment based on Lectures 1-4 (1%)
21/02
Population and the environment: factors affecting population size; biotic
potential, population growth curves – S and J curves; environmental
resistance and carrying capacity; density dependent and density independent
factors; problems caused by overpopulation; factors affecting fertility rates;
population control methods; causes, effects and solutions of urbanisation:
Chapters 8, 9
28/02
Course Test #1; MCQ’s; Duration 1 hr; Lecture (15%)
07/03
Land Pollution: competing uses of land, agriculture & its impact on soil
structure, habitats, food web; soil erosion and conservation methods
Watersheds: trees and their importance; watershed importance and
destruction; trends and issues relating to Jamaican watersheds and forests;
land degradation due to improper physical planning; pesticide use, impacts
and alternative methods of control.
Chapters 14, 17, 18, 22
07/03
Oral Presentations; Tutorial (8%)
14/03
Minerals: mining & use of minerals, impacts of mining.
Energy: Renewable and Non-renewable energy sources; use of fossil fuels;
solar energy, geothermal energy, nuclear energy & their relevance to
Caribbean states; energy conservation and energy efficiency and sustainable
development.
Chapters 10, 11, 12, 15
14/03
Reflective Essays to be handed in (10%)
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21/03
Waste management and recycling: characteristics & sources of solid
waste, methods of solid waste disposal, impact of improper solid waste
disposal, hierarchy of recycling options, advantages & disadvantages of
recycling, impacts of recycling on Caribbean countries.
Chapter 23
28/03
Water and pollution: uses and importance; pollutants and sources; impact
of agriculture and industry; state of Jamaica’s water resources, importance,
impacts and solutions; oceans- importance, impacts of oil pollution and overfishing.
Chapters 13, 21
Air and noise pollution: structure of the atmosphere; sources and type of
pollutants; effects of air pollution, impact of acid rain, increased atmospheric
carbon dioxide and global warming, possible impacts of global warming on
Caribbean states, ozone layer – importance and impacts of halons, impact of
ozone depletion, impact of noise pollution.
Chapters 19, 20
28/03
Graded Class Assignment based on Lectures 7-9 (1%)
04/04
Course Test #2; Short Answers Based on Scenarios; Duration 1 hr;
Lecture (15%)
11/04
Review
Final exam (50%)
Assessment
 Coursework

Individual Assignment
- Reflective Essay (10%)
- Graded Class Assignment (02%)
Group Presentation
Course Test (1)
Course Test (2)
Final Examination
(12%)
(08)
(15%)
(15%)
(50%)
Required Text:
Environment by Raven, Berg and Johnson
Reference Text:
Environmental Science by Kevin Byrne
Web sites:
www.nrca.org, www.uwimona.edu.jm, www.wra-ja.org,
www.ccam.org.jm, www.instituteofjamaica.org.jm, www.cep.unep.org,
www.greenjamaica.com,
www.conservation.org,
www.jsdnp.org.jm
Please use any of the links below to access the lecture notes
and handouts: http://rdmartin-ja.org/lectures.html
OR
http://utechonline.utech.edu.jm/
Use your students log in and your utech username and password
for the second link. Then scroll through and select the
module. The enrolment key is biodiversity.
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Individual Assignment
Description of Assignment
You are required to write a reflective essay on your personal journey or experience in this module.
You will begin this reflection by clearly stating your views on the environment when you first
began this module. You will then indicate whether this view has changed or been influenced by the
module. Finally, you will state how this change/influence is reflected in your actions or give reasons
why your actions have not been influenced. The assignment should be no longer than 5 pages.
Format of Assignment
Introduction - At the starting line
Declare your position or worldview of the environment (as a cornucopian or an environmentalist) at
the beginning of the module. Note that to show this you must explain your attitude and perception
of the environment. Organise the paper logically by selecting a theme (biodiversity, sustainability,
pollution, energy consumption, waste disposal etc). Please ensure that the theme to be reflected on
throughout the essay is properly introduced here.
Body – The journey
For your theme highlight its importance at the global, community and individual levels. Research
and refer to evidence from a newspaper or journal article to support your arguments. Mention at
least two relevant environmental laws or where none exist suggest legislations to address the issue.
State whether or not your actions have been influenced by what you have learnt. If you have been
influenced, discuss two ways in which the new knowledge will change the way you live and work?
If you have not been influenced state two reasons for this.
Conclusion – Recap of the journey
Include a summary of key points and a concluding statement. Do not introduce new information in
the concluding paragraph.
Mark Scheme (Total 25 Marks)
1. Clearly explained environmental world view (1), introduction to theme (1), & outline of
essay (1)
2. Maintenance of the theme chosen throughout the essay (2).
3. Content addressing the following levels.
i.
Global level (2). Supporting reference (1)
ii.
Community level (2). Supporting reference (1)
iii.
Individual level (2). Supporting reference (1)
4. Changes in actions based on new knowledge acquired or reasons for no change in lifestyle
(1x2).
5. Application or suggestion of appropriate environmental laws (2). Information on appropriate
legislation may be obtained from the Jamaica Environment Trust website at:
www.jamentrust.org.
Click on publications, as you scroll down this page you will see the pdf document “It inna di
law”. Read the sections relevant to your issues.
6. Grammar (2)
(Punctuation/sentence construction/spelling)
Errors
Marks
0-5
6-10
11-15
16-20
>20
2
1.5
1
0.5
0
7. Flow of essay (3). Making sure your main points are clearly stated and connect each point to
your thesis as explicitly as possible (1); dividing paragraphs logically (1); and providing
appropriate transitions both within and between paragraphs (1).
8. Conclusion (1). Summary of key points (0.5) and logical concluding statement (0.5)
9. References (1). References complete (0.5) and adhere to APA format (0.5).
Graded Class Assignment
This assignment, done in two parts, requires your response to a short answer question
given at the beginning of the tutorial class. You will have ten minutes to respond and
submit your answers to your tutor. The lectures on which the questions are based is noted
in the schedule. This assignment constitutes 2% of your final grade.
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Group Assignment – Oral Presentation
In groups of three to five you will examine an environmental issue of local or national
significance. Groups are to be formed by Week two and the topics chosen and finalized by
Week 5. You are advised to hold regular discussions on your assignment with your tutor
during the tutorials. The marking scheme to be used is on the next page.
Environmental Studies - Oral Presentation Marking Scheme
TOPIC:
____________________________________________________________
Group Marks (35)
1.
Identify and define topic effectively
5
_____
2.
Portray adequate knowledge of topic in presentation
10
_____
3.
Make presentation flow in an organized manner
5
_____
4.
Group dynamic. Interaction among members
and with audience
5
_____
5.
Use audio-visual aids (overhead projector,
charts, blackboard, handouts, etc) effectively.
5
_____
Relate topic to the Jamaican environment.
5
_____
6.
Individual Marks (15)
Point 1.
Point 2.
Do not read verbatim. Show fluency of topic (5 marks).
Answer questions posed at end of presentation. Each member will get at least
one question (10 marks).
Group Members
Point 1 (5)
Point 2 (10)
Overall Score/50
_______________________
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___________
________
_______________________
__________
___________
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_______________________
__________
___________
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_______________________
__________
___________
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_______________________
__________
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________
The overall score will differ for each group member as it involves combining the Group
and Individual marks.
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UNIVERSITY OF TECHNOLOGY
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies
Lecture #1
INTRODUCTION TO ENVIRONMENTAL STUDIES
What is Environmental Science?
It is the science of understanding how the world works at the level of the natural environment, i.e.
how the natural environment regenerates natural resources and how this regenerative capacity is
being affected by human activities.
In the disputes over environmental issues there are two opposing views; cornucopianism and
environmentalism.
Cornucopianism

This is the dominant worldview held by Western civilisations throughout most of its history. It
embodies the assumption that all parts of the environment, i.e., air, water, soil, minerals and all
plant and animal species are natural resources that must be exploited for the advantage of
humans. This view additionally assumes that these natural resources are infinite. The history of
the development of Western civilisations has consequently been synonymous with the stripping
of forests, slaughter of wild animals, mining of minerals and discarding of wastes with little
thought of pollution or regard for the long term impact on the earth or future generations.
Environmentalism

This embodies the view that what is viewed as natural resources are products of the natural
environment. Consequently, these resources will be limited by the regenerative capacities of the
natural environment, and will be provided only to the extent that the natural environment is
protected and maintained. Our survival therefore depends on suitable protection and
stewardship of the environment.
Ethics
The way humans relate to the environment is determined by ethics, which is the branch of
philosophy that deals with human values.
Environmental ethics is a field of applied ethics that considers the moral basis of environmental
responsibility and how far this responsibility extends. Environmental ethicists try to determine how
humans should relate to nature.
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GLOSSARY OF ENVIRONMENTAL TERMS
Environment: All of the external factors, conditions, and influences which affect an organism or a
community; everything that surrounds an organism or organisms, including both natural and
human-built elements.
Natural Resource – anything produced naturally that is needed by a group of organisms to survive
e.g. fresh water, food, shelter.
Irreplaceable resource – a natural resource that life cannot exist without e.g. the sun’s energy,
earth’s biodiversity.
Renewable resource – resources that are produced continuously, or come from resources that
cannot be exhausted e.g. fresh water, air, soil, trees....
Non-renewable resource – a natural resource that can be used up completely or to the extent that it
becomes too expensive to obtain e.g. fossil fuels, minerals.
Renewable resources are needed more than non-renewable resources.
Resource depletion – when a major fraction of a resource has been used up.
Pollution – an undesirable change in the characteristics of the air, water or land that can adversely
affect the health, survival and activities of humans or other organisms.
Some natural processes cause pollution. However, nearly all pollution that affects us today is
anthropogenic, that is, caused by man.
Biodegradable pollutants: These are pollutants capable of being broken down by living organisms
into inorganic compounds. Ideally all waste should be biodegradable.
Non-degradable pollutants – these cannot be broken down by natural processes and are only kept
out of the environment by not introducing them in the first place.
Sustainable development – Development that ensures that the use of resources and the
environment today does not compromise their use in the future.
Sustainable world – a world that can go on indefinitely providing all things needed to ensure a
high standard of living and health for everyone.
Presently many natural resources are being used up faster than they can be replaced. Unless
substitutes can be found for these resources or ways of conserving them, the standard of living in
the future will fall.
Conservation – using less of a resource or reusing it many times.
Population growth – rapidly growing human population usually exponential which is thought to
exasperate all other environmental issues.
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UNIVERSITY OF TECHNOLOGY
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies
Lecture #2
ORGANISATION OF THE ENVIRONMENT
The environment can be divided into the biological or living component which is known as the
biota and the physical or non-living component known as the abiota. The biota includes all the
organisms: plants, animals and microbes in the ecosystem. The way categories of organisms fit
together is referred to as the biotic structure.
The non-living chemical and physical factors of the environment including the soil quality and
climate are referred to as abiotic factors.
Biotic Structure
Individual:
One organism of a species
Population: A group within a given species, living in the same habitat, the individuals of which
can and do freely interbreed. Breeding between populations of the same species is less common
because of differences in location, culture and nationality.
Species:
Total population of a specific kind of plant, animal or microbe. All the individuals
of a given species can interbreed to reproduce their kind – i.e. fertile offspring of both sexes.
Members of a different species by definition do not interbreed.
Community: Several interacting populations living in a habitat.
Biosphere:
All of the Earth’s communities of organisms
Abiotic structure
Atmosphere:
Gaseous envelope surrounding the Earth.
Hydrosphere:
Earth’s supply of water, liquid and frozen, fresh and salty.
Lithosphere:
The lithosphere is the soil and rock of Earth’s crust.
Biotic and Abiotic Interactions
Ecosystem: Grouping of plants, animals and other organisms interacting with each other and the
non-living component of the environment in such a way as to perpetuate the grouping more or less
indefinitely.
Biome:
Ecosystems with similar vegetation types occurring in different parts of the world are
collectively termed biomes. These are governed by similar types of climatic conditions. Examples
include: tropical rain forests, coniferous forests, grasslands, freshwater lakes and oceans.
Ecotone:
Ecosystems seldom have distinct boundaries and are not independent of each other.
One tends to blend into the next through a transitional region called an ecotone. This region
contains many of the species and characteristics of the two adjacent systems and may include
unique environments that support distinctive plants and animals as well as those that are common to
the adjoining ecosystem.
There are conspicuous ecotones between ocean and freshwater systems in the form of estuaries,
between ocean and land in the form of beaches, wetlands and rocky coastlines.
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Land 
e.g.
Mangrove Swamps 
Coastal Oceans
Oceans include a variety of environments depending on temperature, water, depth, nature of bottom,
concentration of nutrients and sediment. Each of these marine environments support a more or less
distinctive array of seaweed, plankton, fish, shell fish and other marine organisms.
Ecosphere: The worldwide ecosystem. It encompasses the biosphere and its interaction with the
atmosphere, hydrosphere and lithosphere.
THE ENERGY OF LIFE
The sun is the source of energy that powers all life processes. Energy is the capacity or ability to do
work. It exists as stored energy called potential energy or as kinetic energy, the energy of motion.
Chemical energy and nuclear energy are forms of potential energy while forms of kinetic energy
include:




Solar/radiant
Heat
Mechanical
Electrical
The study of energy and its transformations is called thermodynamics.
First Law of Thermodynamics
Energy cannot be created or destroyed although it can be transformed from one form to another. As
a consequence of the first law of thermodynamics, living things cannot create energy but must
capture the energy from the environment. Plants absorb the radiant energy of the sun and convert it
into the chemical energy contained in the bonds of glucose. Animals obtain energy by consuming
plants or other animals.
Second Law of Thermodynamics
When energy is converted from one form to another, some usable energy i.e. energy available to do
work is degraded into a less usable form i.e. heat, that disperses into the environment. As a result,
the amount of usable energy available to do work in the universe decreases over time. Less usable
energy is disorganised. ENTROPY is a measure of this disorder or randomness. Organised or
usable energy has low entropy while disorganised energy such as heat has high entropy.
Photosynthesis and Cell Respiration
Photosynthesis is a biological process in which light energy from the sun is captured and
transformed into the chemical energy found in the chemical bonds of carbohydrate molecules
(glucose). This process uses carbon dioxide and water as raw materials with the release of oxygen
as a byproduct.
6CO2 +12 H2O
carbon dioxide
water
+ radiant energy  C6H12O6 + 6H2O +6O2
glucose
water
oxygen
Respiration is the process by which the chemical energy stored in carbohydrates and other
molecules is released within the cells by the breaking down of these molecules in the presence of
oxygen to form carbon dioxide and water with the release of energy stored in units called ATP –
Adenosine Triphosphate.
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
glucose
oxygen
carbon dioxide
water
Energy Flow Through Ecosystems
The movement of energy in a one-way direction through an ecosystem is known as energy flow. In
an ecosystem energy flow occurs in food chains where energy from food passes from one organism
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to the next in a sequence. Organisms in a community can be divided into categories based on how
they get nourishment.
1. Producers/Autotrophs – these are organisms that trap the sun’s energy to manufacture food
from simple raw materials. These are found at the bottom or the beginning of the food
chain.
2. Primary consumers/ herbivores – these are organisms that feed directly upon producers.
3. Secondary consumers (carnivores/omnivores) – these are organisms that feed on the primary
consumers.
4. Tertiary consumer – these are organisms that feed on the secondary consumers
5. Decomposers (saprotrophs) – these are microorganisms found at any point along the food
chain. They return inorganic material to the environment where they can be reused by other
living organisms.
6. Detritivores (detritus feeders) – some consumers consume detritus, which is organic matter
which includes animal carcasses, leaf litter and faeces e.g. snails, crabs, clams and worms.
A food web is a complex of interconnected food chains in an ecosystem.
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UNIVERSITY OF TECHNOLOGY
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies
BIOGEOCHEMICAL CYCLES
Lecture #3
Matter (the material of which organisms are composed) moves in numerous cycles from one part of
the ecosystem to another i.e. from one organism to another and from living organisms to the abiotic
environment and back again. These cycles are called biogeochemical cycles. There are four major
biogeochemical cycles of matter. These are the carbon cycle, nitrogen cycle, phosphorus cycle and
the water cycle.
Carbon Cycle
The main carbon source for living organisms is carbon dioxide present in the atmosphere or
dissolved in surface waters. The major carbon reservoir is found in the earth’s rocks, followed by
fossil fuels and ocean beds. The major processes occurring in the carbon cycle are photosynthesis
and respiration. Plants use the process of photosynthesis to manufacture plant carbohydrate using
carbon dioxide as a raw material. As such photosynthesis is the only natural process that removes
Carbon dioxide from the environment, an excess of which, as you will learn later in the module has
been implicated as a factor causing global warming. This carbon is in turn passed on to animals
when they eat plants. Through the process of respiration and decomposition, carbon is returned to
the atmosphere. Carbon is also returned to atmosphere by the burning of coal, oil, natural gas and
wood in the process known as combustion. Carbon can also be taken from the reservoir during
various physico-chemical processes and be deposited as limestone (CaCO3).
Nitrogen Cycle
Nitrogen is crucial for all organisms because it is an essential part of biological molecules such as
proteins and nucleic acids. Although the atmosphere is composed of 78% nitrogen gas (N2), a two
atom molecule, this N2 is so stable that it does not readily combine with other elements to form
compounds. There are five major steps:
1.
Nitrogen fixation – this is the conversion of gaseous nitrogen (N2), to ammonia (NH3).
In this process nitrogen gas is fixed into a form that organisms can use. Although N2 can
be fixed by combustion, volcanic action and lightening, most nitrogen fixation is thought
to be biological. Biological nitrogen fixation is carried out by nitrogen fixing bacteria in
soil and aquatic environments.
2.
Nitrification – the conversion of ammonia (NH3) to nitrate (NO3). This is a two-step
process accomplished by bacteria. Nitrosomonas and Nitrococcus convert ammonia to
nitrite (NO2) then Nitrobacter oxidises nitrite to nitrate.
3.
Assimilation – this is where plant roots absorb either nitrate or ammonia that was formed
by nitrogen fixation and incorporate the nitrogen into proteins and nucleic acids.
4.
Ammonification – the conversion of biological nitrogen compounds into ammonia. This
begins from waste products and decomposition of organisms. The bacteria that perform
these processes are called ammonifying bacteria.
5.
Denitrification – this is the reduction of nitrate to gaseous nitrogen. Denitrifying
bacteria reverse the action of nitrogen fixing and nitrifying bacteria by returning nitrogen
gas to the atmosphere.
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Phosphorus Cycle
The phosphorus cycle has no biologically important gaseous compounds. Phosphorus erodes from
rock in the form of inorganic phosphates, which are absorbed from the soil by plant roots.
Phosphorus enters other organisms through the food web and is released back into the environment
as inorganic phosphate by decomposers. When phosphorus washes into the ocean and is deposited
in sea beds, it can be lost from biological cycles for millions of years.
Hydrological Cycle
Water continuously circulates from the ocean to the atmosphere to the land and back to the ocean,
providing us with a renewable supply of purified water on land. Water moves from the atmosphere
to the land and ocean in the form of precipitation. Water evaporates from the ocean, from soil,
stream, rivers and lakes to form clouds in the atmosphere. Transpiration from plants also
contributes to cloud formation. Apart from evaporation from land, water may flow from land into
rivers and streams known as run-off. The area of land being drained by run-off is called a
watershed. Water also percolates or seeps downward through the soil and rock to become ground
water.
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The Carbon Cycle
combustion
The Nitrogen Cycle
Denitrification
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The Phosphorus Cycle
The Hydrological Cycle
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UNIVERSITY OF TECHNOLOGY
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies
ECOSYSTEMS AND LIVING ORGANISMS
Lecture #4
The environment in which an organism lives will be determined by a range of physical or abiotic
factors such as light, heat and moisture as well as by the influence of other living organisms (biotic
factors).
Interactions among living organisms
The biotic factors which affect the survival and distribution of an organism include:



Intraspecific factors – those that occur between members of the same species such as
competition for food and territory.
Interspecific factors – those that occur between members of different species such as
predator-prey interactions, host-parasite interactions.
Humans – we have become the predominant biotic influence on the distribution and success
of other species.
Important interspecific associations are symbiosis, predation and competition.
SYMBIOSIS
Symbiosis is the living together in close association of two or more organisms of different species.
Nutrition is usually involved. There are three common types of symbiotic relationships.
Mutualism
This is a symbiotic relationship in which both partners benefit. The association between nitrogen
fixing bacteria of the genus Rhizobium and legumes is an example of symbiosis. Rhizobium
supplies the plant with all the nitrogen it needs and the legumes supply sugar to their bacterial
symbionts. Another example of commensalism involves the clown fish which dwells within the
tentacles of the sea anemone on the coral reef. These tentacles possess stinging cells. The clown fish
themselves are not affected by the tentacles. They, however, lure predatory fish into the tentacles
which are then captured by the anemone’s tentacles, stung, stunted and ingested by the anemone.
The clown fish on the other hand is protected from predation living among the anemone’s tentacles.
http://windmountain.files.wordpress.com/2009/02/clownfish_sprain_water3.jpg
Commensalism
Commensalism is a type of symbiosis in which one organism benefits (the commensal) and the
other is neither harmed nor helped. Example is the relationship between a tropical tree and its
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epiphytes (mosses, orchids and ferns), that live attached to the bark of the tree. The epiphyte
anchors itself to the tree but obtains neither water nor nutrients directly from the tree. Its location
on the tree enables it to obtain adequate light, water (as rainfall dripping down the branches) and
required minerals (washed out of the tree’s leaves by rainfall). Thus, the epiphyte benefits from the
association, whereas the tree is apparently unaffected.
Parasitism
Parasitism is a symbiotic relationship in which one member, the parasite, benefits and the other, the
host is adversely affected. The parasite obtains nourishment from the host, but although a parasite
may weaken its host, it rarely kills it. Parasites which live on the outer surface of a host are termed
ectoparasites e.g. ticks, fleas, leeches. Those that live within a host are endoparasites e.g.
tapeworms.
For more on intriguing symbiotic relationships found in the marine environment check out the
following link: http://www.ms-starship.com/sciencenew/symbiosis.htm
Predation
Predation is the consumption of one species, the prey, by another, the predator. It includes both
animals eating other animals and animals eating plants.
COMPETITION
When two species are very similar, their fundamental niches may overlap. Many ecologists believe
that no two species can indefinitely occupy the same niche in the same community, because
competitive exclusion eventually occurs. In competitive exclusion, one species is excluded from a
niche by another as a result of competition between species i.e. interspecific competition. Although
it is possible for different species to compete for some necessary resource without being total
competitors, two species with absolutely identical ecological niches cannot coexist. Coexistence
can occur if the overlap in the two species niche is reduced.
The potential ecological niche of an organism is its fundamental niche, but various factors such as
competition with other species may exclude it from part of its fundamental niche. Thus, the
lifestyle that an organism actually pursues and the resources that it actually uses make up its
realised niche.
EVOLUTION AND SUCCESSION
Evolution is the theory that the various types of animals and plants have their origin in other
preexisting types and that the distinguishable differences are due to modifications in successive
generations.
The 19th century English naturalist Charles Darwin argued that organisms come about by evolution,
and he provided a scientific explanation, essentially correct but incomplete, of how evolution occurs
and why it is that organisms have features – such as wings, eyes, and kidneys – clearly structured to
serve specific functions. Natural selection was the fundamental concept in his explanation.
Darwin’s Theory of Natural Selection
Fact #1 – Without constraints, populations will grow exponentially, producing an ever more rapidly
growing number of organisms.
Fact #2 – In spite of this prediction, the numbers of individuals in a population remains near
equilibrium, fluctuating above or below some mean value.
Fact #3 – Resources are limited. From this fact, Malthus concluded that there was a struggle for
existence. Darwin combined this with two additional facts:
Fact #4 – Individuals are unique. There is individual variation. This came from observing animal
breeding.
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Fact #5 – Much (but not all) of the individual variation is hereditable. This observation also came
from animal breeders. (Some of observed variation is environmental, some is genetic.)
These facts led Darwin to conclude that some individuals are better equipped to survive and
reproduce (Natural Selection). Through many generation of time, evolution is the result. (Darwin
used “descent with modification”)
A nice example of natural selection was discovered among “peppered” moths living near English
industrial cities. These insects have varieties that vary in wing and body colouration from light to
dark.
During the 19th century, sooty smoke from coal burning furnaces killed the lichen on trees and
darkened the bark. When moths landed on these trees, the dark coloured ones were harder to spot
by birds, and subsequently, they more often lived long enough to reproduce. Over generations, the
environment continued to favour darker moths. As a result they progressively became more
common. By 1900, 98% of the moths in the vicinity of English cities like Manchester were mostly
black.
Since the 1950’s, air pollution controls have significantly reduced the amount of pollutants reaching
the trees. As a result, lichen has grown back, making trees lighter in colour. Now, natural selection
favours lighter moth varieties so they have become the most common.
Succession
The orderly replacement of one ecosystem by another is a process known as ecosystem
development or ecological succession. Succession occurs when a sterile area such as a lava flow, is
first colonised by living things, or when an existing ecosystem is disrupted, as when a forest is
destroyed by fire.
Types of succession
Two different types of succession, primary and secondary, have been distinguished.
Primary succession occurs in essentially lifeless areas – regions in which the soil is incapable of
sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from
a retreating glacier.
Secondary succession occurs in areas where a community that previously existed has been
removed; it is typified by smaller-scale disturbances that do not eliminate all life and nutrients from
the environment. Events such as fire that sweeps across a grassland or a storm that uproots trees
within a forest create patches of habitat that are colonised by early successional species. Depending
on the extent of the disturbance, some species may survive other species may be recolonised from
nearby habitats, and others may actually be released from a dormant condition by the disturbance.
For example, many plant species in fire-prone environments have seeds that remain dormant within
the soil until the heat of a fire stimulates them to germinate.
For more on succession you may view the following link:
http://uk.encarta.msn.com/encyclopedia_781534152/Succession_(ecology).html
WEATHER AND CLIMATE
Weather refers to the conditions in the atmosphere at a given place and time. Climate comprises the
average weather conditions that occur in a place over a period of years. The two most important
factors that help to determine an area’s climate are temperature and precipitation. Precipitation
refers to any form of water such as rain, snow, sleet or hail that falls to the Earth from the
atmosphere. Earth has many different climates, and because each is relatively constant for many
years, organisms have adapted to them.
BIOMES
A biome is a large, relatively distinct terrestrial region characterised by similar climate, soil, plants,
and animals regardless of where it occurs in the world. There are nine major biomes of the world.
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These are the tundra, taiga, temperate rain forest, temperate deciduous forest, temperate grassland,
chaparral, desert, savannah and tropical rainforest.
TUNDRA – this is the northernmost biome. It is characterised by permafrost (layer of ice
underlying a thin soil layer), by low growing vegetation and by a very short growing season.
TAIGA – or boreal forest, lies south of the tundra and is dominated by large conifers
TEMPERATE DECIDUOUS FOREST – occurs where precipitation is relatively high and is
dominated by broad-leaved trees that lose their leaves with the seasons.
TEMPERATE GRASSLANDS – typically possess deep, mineral rich soil, have moderate
precipitation and are well suited to growing grain crops.
CHAPPARAL – characterised by thickets of small-leaved evergreen shrubs and trees and a climate
of wet, mild winters and very dry summers.
TROPICAL GRASSLAND – also called savannahs, have widely scattered trees interspersed with
grassy areas.
DESERTS – found where there is little precipitation and have communities that are specially
adapted for water conservation.
TROPICAL RAIN FOREST – Found in Central, South America, Africa and Southeast Asia and
covers 6% of the earth’s land area. Occur where temperatures are warm throughout the year and
precipitation occurs almost daily. Yearly precipitation is 200-400 cm. These areas have highly
weathered, mineral poor soils. It is rich in species diversity with no single species dominating the
biome. Trees form dense multi-layered canopy. Roots are often shallow, concentrating near the
surface in a mat only a few cms thick. Animals include the most abundant and varied insects,
reptiles and amphibians on Earth. Birds are varied and are often brightly coloured.
Deforestation is a major problem in tropical rain forests. 40% of tropical deforestation occurs in S.
America. Haiti has lost 98%, Philippines 97% and Madagascar 84% of its original forest cover.
Deforestation is a complex problem with three major agents. These are subsistence agriculture,
commercial logging and cattle ranching.
To learn more about the world’s biomes you may visit the following link. You will notice that the
definition of the term “biome” has been expanded to include aquatic ecosystems. You will,
however, find information on the biomes listed in the text above.
http://www.ucmp.berkeley.edu/exhibits/biomes/index.php
CARIBBEAN COMMUNITIES
Coral Reefs
Coral reefs are collections of biological communities which represent some of the most diverse in
the world. Corals are tiny plant-like animals that depend on clean, clear, warm, shallow sea water
to survive. The coral animals require light for the large number of symbiotic algae, known as
zooxanthellae that live and photosynthesize in their tissues. Corals live in colonies consisting of
many individuals, each of which is called a polyp. They secrete a hard calcium carbonate skeleton,
which serves as a base or substrate for the colony as well as it provides protection. Coral reefs grow
slowly, as coral animals build on the calcareous remains of organisms before them. There are three
different types of coral reefs: fringing, barrier and atoll.
Coral reefs are important to the Caribbean because they:
 provide habitat for marine creatures
 are a source of food
 have commercial value such as being a resource for tourism
 control carbon dioxide levels in the ocean
 protect coastline from wave action
 have medicinal value
 provide sediments for white sand beaches
 are a nursery and breeding ground for many aquatic species
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Coral reefs are threatened by:
 disease
 tropical storm damage
 wave action
 warmer ocean temperatures
 overfishing
 destructive fishing methods
 pollution
 oil spills
 increased sedimentation
 mangrove removal
Mangroves
Mangrove refers to a plant community which lies between the sea and the land in areas which are
inundated by tides. Mangrove trees are the only trees that can survive in salt water. There are three
main types found in Jamaica – Red mangroves, Black mangroves and White mangroves.
Mangroves provide valuable environmental services that include:
 protecting the coastline from erosion and reducing damage from hurricanes
 protecting the quality of coastal water by diluting, filtering and settling out sediments,
excess nutrients and pollutants
 trapping storm water preventing excess fresh water entering coastal waters
 providing habitat, nursery, breeding and fishing grounds for many species of fish,
invertebrates and plants
Mangroves are threatened by:
 excessive siltation and sedimentation
 stagnation and surface water impoundment
 major oil spills
 reduction in fresh water inflows and alteration in flushing patterns
 clear felling of trees
 dumping and filling of mangroves to build hotels, housing schemes.
Seagrass Beds
Seagrasses are submerged marine plants occupying shallow coastal waters. These organisms being
plants require availability of sunlight to survive. The three species dominating the tropical western
North Atlantic and Caribbean coastal environments are Thalassia testudinum, Syringodium filiforme
and Halodule wrightii.
Seagrasses:
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stabilize the sediment and prevent turbidity which would otherwise affect the health of coral
reefs usually found adjacent to seagrass beds.
absorb some of the nitrates and phosphates in water coming from land run-off which reduces
the amount reaching adjacent coral reefs.
provide many habitats and microhabitats for host of marine and commercially significant
organisms.
serve as breeding grounds and foraging areas for coral reef organisms.
By virtue of being close to the coastline which over the past decades are becoming more
industrialized, seagrass beds are threatened by:
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release of excess nutrients (nitrates and phosphates) into coastal water.
removal of seagrass beds by dredging for construction.
propeller damage caused by boating activities.
anchoring
deployment of moorings
fishing and recreational sport activities
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For more about mangrove forests and seagrasses view the following link which contains a
presentation compiled by NEPA:
http://www.nepa.gov.jm/presentation/overview-mangroves-seagrass.pdf
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UNIVERSITY OF TECHNOLOGY
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies
Lecture #5
BIODIVERSITY
Biodiversity is the variety of living organisms and the ecosystems and ecological processes of
which they are a part.
Biodiversity can be divided into three categories.
a)
Species Diversity:
refers to the variety of living organisms within a region
b)
Genetic Diversity:
refers to the variety of genes within a species
c)
Ecosystem Diversity: refers to the variety of habitats, biotic communities and ecological
processes in the biosphere.
Biologists estimate that there are between five (5) million and thirty (30) million species, with a best
estimate of ten (10 million). Only 1.4 million species have been named. The greatest species
diversity is exhibited by microbes, insects and small sea organisms.
The areas richest in biodiversity are the tropical moist forests of Southeastern Asia, Central Africa
and West Central Africa and Tropical Latin America.
Importance of Biodiversity
a)
Agricultural Importance
Human beings and other animals depend on plants to provide them with food. However,
the number of different kinds of food we eat is limited when compared with the total
number of edible species. About eighty thousand (80,000) are thought to be edible, but
only 150 are used as human food.
At least 1650 known tropical forest plants have potential as vegetable crops. Only a few
species of animals have been domesticated for food production. Virtually 100% of the
protein from domesticated animals consumed by people comes from nine species: cattle,
pigs, sheep, goats, chickens, ducks, geese and turkeys.
b)
Industrial Importance
Modern industrial technology depends on a broad range of genetic material from
organisms, particularly plants that are used in many products. Plants supply oils,
lubricants, perfumes and fragrances, dyes, paper, lumber, waxes, rubber, resins, poisons,
corks and fibres while animals provide wool, silk, fur, leather, lubricants, waxes and
transportation.
The neem tree has been found to be a source of insecticide, spermicides and agents
potentially valuable in birth control such as materials that prevent implantation.
Daisy plants (used centuries ago as a lice remedy in the Middle East) led to the
discovery of pyrethrum insecticides. It is one of the safer insecticides since it
decomposes rapidly in sunlight, has few known effects on mammals and insects do not
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develop resistance to it. It is used on foodstuffs, in head lice shampoos, in indoor insect
sprays and mosquito coils.
c)
Medicinal Importance
The genetic resources of organisms are vitally important to the pharmaceutical industry,
which incorporates hundreds of chemicals derived from organisms into its medicines.
About a quarter of all prescription drugs are taken directly from plants or are chemically
modified versions of plant substances and more than half of them are modelled on
natural compounds. Examples of these products include morphine, codeine, quinine,
atropine and digitalis.
Animals too continue to be sources of drugs and are important in medical research.
d)
Ecosystem Stability
Plants, animals, fungi and other microorganisms are instrumental in many environmental
processes without which humans could not exist.
Forests provide watersheds, from which we obtain water, and reduce the severity and
number of local floods. Many species of flowering plants depend on insects to transfer
pollen for reproduction. Soil dwellers from earthworms to bacteria develop and maintain
soil fertility for plants. Bacteria and fungi decompose organic materials, which allows
nutrients to recycle in the ecosystem.
e)
Scientific Importance
It is important to maintain a broad genetic base for organisms, which are economically
important. Plant scientists have developed genetically uniform, high yielding varieties
of important food crops such as wheat. However, genetic uniformity resulted in
increased susceptibility to pests and diseases.
By crossing these “super strains” with genetically more diverse relatives, disease and
pest resistance can be reintroduced into such plants.
Wild plants therefore represent important sources of genes that can confer useful
properties to conventional crops.
f)
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Wild tomato discovered in the Andes has been used to increase the sugar content in
cultivated species.
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Rice grain in Asia is protected from the main rice diseases by genes brought in from
a wild species from India.
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The sugar cane industry in the US was saved from collapse by disease resistant genes
brought in from wild Asian species.
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A wild barley plant from Ethiopia provided a gene that protects California barley
crop from lethal yellow dwarf virus.
Genetic Engineering, which is the incorporation of genes from one organism into an
entirely different species, makes it possible to use the genetic resources of organisms on
a much wider scale.
The gene for human insulin has been engineered into a bacterium which subsequently
became tiny chemical factories manufacturing at a relatively low cost the insulin
required in large amounts by diabetes. Genetic engineering has provided us with new
vaccines, more productive farm animals and agricultural products with longer shelf life
and other desirable characteristics.
Genes cannot be made; hence engineering depends on the availability of a broad base of
genetic diversity from which genes can be obtained.
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g)
Aesthetic Value
Organisms provide recreation, inspiration and spiritual solace. The natural world is a
thing of beauty because of its diversity.
h)
Ethical Value
The strongest ethical consideration regarding the value of organisms is how humans
perceive themselves in relation to other species. The traditional view is that humans are
masters of the rest of the world subduing and exploiting other forms of life for their
benefit.
An alternative view is that organisms have intrinsic value in and of themselves and that
as stewards of the life forms on Earth, humans should watch over and protect their
existence. Deep ecology is the conviction that organisms have a right to exist and that
humans should not cause the extinction of other organisms.
SPECIES ENDANGERMENT AND EXTINCTION
Threatened Species: A threatened species is any species of animal, plant, fungi etc. which is
vulnerable to extinction in the near future. According to the IUCN (International Union for the
Conservation of Nature), the leading authority on the world’s threatened species there are three
categories of threatened species based on the degree to which they are in danger of extinction.
These include:
1. Vulnerable Species – these are the least critical in terms of endangerment. These species are
likely to become endangered unless circumstances threatening its survival and reproduction
improve e.g. cheetah, lion, polar bear, komodo dragon. Vulnerability is usually caused by
habitat destruction or complete habitat loss.
2. Endangered Species – these are species which face a very high risk of extinction in the
near future, e.g. blue whale, giant panda, tiger, Tasmanian devil, harp seal. These species
are in danger of extinction due to their relatively few numbers due to environmental
changes, increased predation pressure and/or habitat destruction. According to the IUCN
approximately 40% of all organisms on earth (based on the sample of species that were
evaluated through 2006) are endangered.
3. Critically Endangered Species – these species face an extremely high risk of extinction in
the immediate future e.g. Mountain Gorilla, Javan Rhino. This is the highest risk category
according to IUCN nomenclature. Critically endangered species have also been described as
those whose population numbers have decreased, or will decrease by 80%, within three
generations.
Extinct species:
A species that no longer survives anywhere in the world. A species is not
considered to be extinct until extensive surveys are done to ensure that no individual of the species
may be found on earth. Some species which are thought to be extinct but there is not yet certainty
are still categorized as “critically endangered”. The IUCN has put in place two categories of extinct:
“extinct” and “extinct in the wild”. The latter suggests that there are some individuals of the species
in question in captivity but none may be found in the wild.
Mass Extinction:
refers to certain periods in the earth’s history (5 to 6 times) during which
numerous species disappeared during a relatively short geological time period.
Range:
refers to the particular area in which a species is found.
Characteristics of Endangered Species
i)
Occupy an extremely small (localised) range. This makes them particularly prone to
extinction if their habitat is altered.
ii)
Species require a large territory to survive and may be threatened with extinction when
all or part of their territory is modified by human activities. E.g. condour.
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iii)
Species live on islands
Many island species that are endemic to certain islands are endangered. These
organisms have smaller populations that cannot be replaced by immigration should their
numbers be destroyed.
Island species evolved in isolation from competitors, predators and disease organisms
and are relatively defenseless when these organisms are introduced into their habitats,
usually by human beings.
iv)
Low reproductive rates: the female blue whales produce a single calf every other year.
v)
Breed only in specialised areas: green turtles lay eggs only on a few beaches.
vi)
Highly specialised feeding habits: giant panda eats only bamboo
In order for a species to survive its members must be present within their range in large enough
numbers for males and females to mate. The minimum population density and size that ensures
reproduction success varies from one type of organism to another. If population density and size
falls below a critical minimum level the population declines, becoming susceptible to extinction.
Endangered and threatened species represent a decline in biodiversity, because as their numbers
decrease their genetic variability is severely diminished.
To be more informed about endangered species and their protection visit the following links
http://www.worldwildlife.org/species/
http://www.youtube.com/watch?v=Psv98volu0U – video clip
Human Causes of Species Endangerment and Extinction
Most species facing extinction today are endangered because of the destruction of habitats by
human activities. Even habitats that are left undisturbed are degraded by human produced acid rain,
ozone depletion, and climate change.
Biotic pollution is the introduction of foreign or exotic species into an area where it is not native.
This often upsets the balance among the organisms living in that area. The foreign species may
compete with native species for food or habitat or may prey on them. Humans are usually
responsible for biotic pollution.
Hunting – Sometimes species become endangered or extinct as a result of deliberate efforts to
eradicate or control their numbers. Many of these species prey on game animals or livestock. In
addition to predator and pest control, hunting is done for three other reasons:
 Subsistence hunting – kill animals for food
 Sport hunting – kill animals for recreation
 Commercial hunters – Kill animals for profit
Conservation Biology
This is the study and protection of biological diversity. It includes two types of efforts that are being
made to save organisms from extinction:
 In situ conservation – this includes the establishment of parks and reserves. It concentrates
on preserving biological diversity in nature. Restoring damaged or destroyed habitats.
 Ex situ conservation – this involves conserving biological diversity in human controlled
settings e.g. breeding of captive species in zoos and the seed storage of genetically diverse
plant crops. Special techniques such as artificial insemination and embryo transfer are also
examples.
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UNIVERSITY OF TECHNOLOGY
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies
Lecture #6
POPULATION ECOLOGY
Population ecology deals with the number of a particular species that are found in an area and how and
why those numbers change or remain fixed over time. The rate of change, or GROWTH RATE (r) of a
population is the birth rate (b) – the death rate (d); R = b – d
Migration must also be considered when changes in population on a local scale are examined. There are
two types of migration: Immigration – by which individuals enter a population and thus increase the
size of the population and emigration – by which individuals leave a population and thus decrease its
size. Therefore the growth rate of a local population must take into account the birth rate (b), the death
rate (d), immigration (i) and emigration (e).
R = (b-d) + (i-e)
The maximum rate at which a population could increase under ideal conditions is known as its biotic
potential. A population growing at its biotic potential shows a typical J-shaped curve when plotted
against time. This curve, characteristic of exponential growth cannot continue indefinitely. This is
because the environment sets limits on population growth collectively called environmental resistance.
Over longer periods of time the growth rate for most organisms decrease to approximately zero at a
point known as the carrying capacity (k). The carrying capacity represents the largest population that
can be maintained for an indefinite period of time by a particular environment. When such a population
that is regulated by environmental resistance is plotted over longer periods of time, the curve has a
characteristic S-shaped or sigmoid growth curve.
There are mechanisms operating to regulate population size. These factors can be density dependent or
density independent. Density dependent factors include diseases and famine while density independent
factors include fires and hurricanes.
The Human Population
The human population has been increasing exponentially since 1800, as seen by its characteristic
J-shaped growth curve. Thomas Malthus (1766-1834) a British economist was one of the first persons
to recognise that the human population cannot continue to increase indefinitely. He believed that the
inevitable consequences of population growth were famine, disease and war. The world population was
5.77B in 1996, an increase of 69M from 1995 to 1996. This increase in population numbers is mainly
due to a decrease in the death rate. The main unknown factor in predicting the human population size is
the Earth’s carrying capacity. No one knows how many humans can be supported by Earth and
projections and estimates vary widely.
Overpopulation
A country is overpopulated if the level of demand on its resource base results in damage to the
environment. A country can be overpopulated by people overpopulation or consumption
overpopulation. Population growth is also influenced by geographical distribution of people in rural
areas, cities and towns. The increasing convergence of populations in cities is known as urbanisation.
This seems to be a factor in decreasing fertility rates. The total fertility rate of the human population is
influenced by cultural traditions, women’s social and economic status, marriage age and education of
women.
Human population and distribution: Urbanisation
 Nearly half the world’s population will be in urban centres by the year 2000. In 1980, nearly one in
three persons was an urban dweller. The rapidity of recent population growth has been greater in the
developing world.
 Shift attributable more to immigration than to natural increase in population;
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 Causes based in concentration of world economy in urban centres, with necessary infrastructure to
deal with communication, production and trade. Service industries sometimes are rurally sited, but
high technology provisions make them essentially urban in nature.
 Rapid urban population growth requires additional supportive, infrastructure and quickly. Urgent
also are shelter and provision for services: health education. Electricity, security and protection,
employment, recreational facilities.
 In developing countries, pressure for shelter results in the formation of ‘ghettos’ on marginal lands
and without hope of proper supplies of water, electricity, schools or arrangements for disposal of
waste.
 Pressure for employment leads to development of an informal entrepreneurial sector in which levels
of success varies. Some businesses are base on the retail trade, some on exporting selected craft/
agricultural items, other on farming for the home market.
 In industrialised countries, pressures have led to inner-city decay, unemployment an migration of
younger and more educated individuals.
 Ecologically, urban centres draw heavily on the environment, that is land, energy, food, waste,
oxygen resources and contribute little. The effects are not locally confined since these resources
often come from other places. They also concentrate heat and air pollution which affects regional
and probably global atmospheric systems.
 Urban centres concentrate environmental problems, e.g., disposal of waste, pollution including noise
pollution and disease.
 Some ghettoes are situated in flood prone areas or near dumps, inviting the spread of disease. In
other squatter settlements, people have to put up fairly substantial dwellings on land they do not
own.
 The general unhygienic conditions lead to disease, malnutrition and poor quality of life.
 Overcrowding and unemployment encourages violence, crime and drug abuse.
Thus urbanisation encourages ecological stress on both the natural and the socio-cultural environment.
Solutions to the problems must have as an integral component means of alleviating this stress, including
ways of promoting balance in ecosystems and maintaining cultural and social diversity for encouraging
stability in human affairs.
Attempts have to be made to discourage the trend towards urbanisation by providing better employment,
infrastructure, education and recreational facilities in rural areas. The net effect should be economic
growth, which allows for improved protection of natural earth systems, and a better distribution of
human population. All of this should make for the possibility of more sustainable improvement in the
quality of human fife and in the ecological health of the environment as a whole.
Below are suggested some specific measures, which might be used to relieve some of the environmental
pressures, engendered by urbanisation.
SOME SOLUTIONS TO PROBLEMS:
 Regularise ownership of land where squatters have settled for a long time e.g. Operation Pride
 Provide educational opportunities for upgrading managerial skills of small business people e.g.
Entrepreneurial Extension Centre, UTECH.
 Initiate collaboration of government, private sector, the church and citizen’s associations in
providing skill training centres and recreational facilities for young people from these deprived
settings e.g. St Patrick’s Foundation.
 Take preventative measures by a) providing similar facilities in villages and small towns and b)
strengthening the resource capacity and political authority of local government bodies
 Practice careful planning and zoning of separate industrial and residential areas to lower risk of
respiratory ailments etc. from pollution
 Encourage urban agriculture to help in food resources e.g. backyard gardens
 Promote recycling, beginning from the individuals and household level
 Put in place strict legal measures to control noise pollution. E.g. from dances, discotheques. Recent
legislation in this respect – will it be enforced? No
 Control of effect of vehicular traffic by making use of unleaded fuel mandatory; encouraging car
pools; providing fast, good public transportation system; providing cycling lanes.
 Control construction legally by strict building codes. Buildings should reflect styles best suited for
local climatic conditions and resources, instead of being copied from others as often happens in the
case of the poorer, tropical/sub-tropical countries an the industrialised ‘north’. In the Caribbean, due
thought must also be given to hurricane and earthquake resistance.
FACTORS INFLUENCING POPULATION GROWTH
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A country can influence the size and rate of growth or decline of its population by encouraging a change
in any of three basic demographic variables: birth, deaths and migration.
Controlling Migration
Only a few countries, chiefly Canada, Australia and the United States allow large annual increases in
population from immigration, and some countries encourage emigration to reduce population pressures.
Reducing Births
Because raising the death rate is not ethically acceptable, lowering the birth rate is the focus of most
efforts to slow population growth.
Reducing Births through Economic Development
Surveys have been carried out on the birth and death rates of western European countries, and from
these data, a hypothesis of population change was developed known as the demographic transition. As
countries become more industrialized, first their death rates and then their birth rates decline.
Pre-Industrial Stage - harsh living conditions lead to high birth rate (to compensate for high infant
mortality) and a high death rate. Thus there is little change in population growth.
Transitional Stage - Industrialization begins, food production rises, and health care improves. Death
rate drop and birth rates remain high, so the population grows rapidly (typically 2.5-3% a year)
Industrial Stage
- Industrialisation is widespread. The birth rate drops and eventually approaches
the death rate. Reasons for this convergence of rates include better access to birth control, decline in the
infant mortality rate, increased job opportunities for women, and the high cost of raising children most
of whom don’t enter the work force until after high school or college. Population growth continues, but
at a slower and perhaps fluctuating rate, depending on economic conditions. Most MDC’s are now in
this third stage and a few LDC’s are entering this stage.
Post-Industrial Stage - Birth rate declines even further, equalling the death rate and thus reaching zero
population growth. Then the birth rate falls below the death rate, and the total population size slowly
decreases. Emphasis shifts from unsustainable to sustainable forms of economic development. Only a
few countries, most of them in Western Europe, have entered this phase.
In most LDC’s today, death rates have fallen much more than birth rates. In other words, these LDC’s
mostly in Southeast Asia, Africa and Latin America are still in the transitional stage, halfway up the
economic ladder, with high population growth rates. Some economists believe the LDC’s will make the
demographic transition over the next few decades without the increased family-planning efforts. But
many population analysts fear that the rapid population growth in many LDC’s will outstrip economic
growth and overwhelm local life-support systems, causing many of these countries to be caught in a
demographic trap.
Reducing Births through Family Planning
Family planning provides educational and clinical services that help couples choose how many children
to have and when to have them. It saves society money by reducing the need for various social services.
Proponents also argue that providing access to family planning throughout the world would brig about a
sharp drop in the estimated 50 million abortions per year.
Using Economic Rewards and Penalties to Reduce births
Some population experts argue that family planning, even coupled with economic development, cannot
lower birth and fertility rates quickly enough to avoid a sharp rise in death rates in many LDC’s. The
main reason for this contention is that most couples in LDC’s want three or four children, which is well
above the replacement level required to bring about eventual population stabilisation.
These analysts believe that we must go beyond family planning and offer economic rewards and
penalties to help slow population growth. About 20 countries offer small payments to individuals who
agree to use contraceptives or be sterilised; however, such payments are most likely to attract people
who already have all the children they want. These countries also pay doctors and family planning
workers for each sterilisation they perform and each IUD they insert. Some countries including China,
penalises couples who have more than one or two children by raising their taxes, charging other fees, or
not allowing income tax deductions for a couple’s third child. Families who have more than the
prescribed limit may also lose health care benefits, food allotments and job options.
Reducing Births by Empowering Women
Women tend to have fewer and healthier children and live longer when they have access to education
and paying jobs outside the home, and when they live in societies in which their individual rights are not
suppressed. Today women do almost all the world’s domestic work and child care, and provide more
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health care with little or no pay than all the world’s organised health services combined. They also do
more than half the work associated with growing food, gathering fuel-wood and hauling water.
Although women work two-thirds of all hours worked, they receive only one-tenth of the world’s
income and own a mere 0.01% of the world’s property. In most LDC’s women don’t have legal right to
own land or borrow money to increase agricultural productivity. Women also make up almost twothirds of the more than 950 million adults who can neither read nor write.
POPULATION DISTRIBUTION
Urbanisation and Urban problems
Today about 43% of the world’s population lives in urban areas and by 2025 this figure is expected to
increase to 61%. Because cities are the main centres for new jobs, education, innovation, culture and
trade, people are drawn to urban areas in search of jobs and better life. They may also be pushed into
urban areas by modern mechanised agriculture, which uses fewer farm labourers and allows larger land
owners to buy out subsistence farmers who cannot afford to modernise. Without jobs or land, these
people are forced to move to the cities. Urban growth in LDC’s is also fuelled by government policies
that distribute the most income and social services to urban dwellers at the expense of rural dwellers.
Poverty is becoming increasingly urbanised as more poor people migrate from rural to urban areas,
especially in Latin America. At least 1 billion people – 18% of the world’s population live in the
crowded slums of central cities and in the vast, mostly illegal squatter settlements or shanty towns that
ring the outskirts of most cities in LDC’s. Many cities refuse to provide squatter settlements with
adequate drinking water, sanitation facilities, electricity, food, health care, housing, schools or jobs. Not
only do these cities lack the needed money, but their officials fear that improving services will attract
even more of the rural poor.
Despite joblessness, squalor, overcrowding, environmental hazards and rampant disease, most squatter
and slum residents are better off than the rural poor. With better access to family-planning programs,
they tend to have fewer children, who have better access to schools. Many squatter settlements provide
a sense of community and a vital “safety net” of programs for the poor.
Urban Resource & Environmental Problems
 Most cities have relatively few trees, shrubs, and other natural vegetation that absorb air
pollutants, give off oxygen, help cool the air, muffle noise, provide wild life habitats, and give
aesthetic pleasure.
 Most cities produce little of their own food
 Cities are generally warmer, rainier, foggier, and cloudier than suburbs and nearby rural areas.
The enormous amounts of heat generated by cars, factories, furnaces, lights, air conditioners,
and people in cities creates an urban heat island surrounded by cooler suburban and rural areas.
 Many cities have water supply and flooding problems.
 Urban areas produce large quantities of air pollution, water pollution, garbage and other solid
waste. There is also excessive noise pollution.
 Urban areas have beneficial and harmful effects on human health. Beneficial effects include
better access to education, social services, and medical care. Harmful effects include increased
likelihood of infectious disease spreading, physical injuries, and health problems caused by
increased exposure to pollution and noise.
 Urban areas expand and swallow up rural land, especially flat or gently rolling land with welldrained, fertile soil.
Solutions:
Ecocities





Matter and energy resources are used more efficiently
Far less pollution are produced
Emphasis is placed on pollution prevention, reuse and recycling
Per capita solid waste production is greatly reduced
Trees and plants adapted to local climate are planted to provide shade and beauty, to reduce
pollution and noise and to supply habitats for wildlife
 Nearby forests, grasslands, wetlands, and farms are preserved.
 Much of the ecocity’s food is nearby organic farms, solar greenhouses, community gardens
 Residents walk, bike, or use low pollution mass transit.
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UNIVERSITY OF TECHNOLOGY, JAMAICA
FACULTY OF SCIENCE AND SPORT
Module:
Environmental Studies ENS 3001
TUTORIAL QUESTIONS – Lectures 1-6.
LECTURE 1 – Introduction to concepts and issues
1.
What are natural resources? Name the two categories and explain the differences
between them, providing examples.
2.
What is pollution? Distinguish between degradable and non-degradable pollutants.
Which type of pollutant has a greater impact on the environment?
3.
Provide a list of the environmental problems affecting the Caribbean and the planet
generally? What are the root causes of these problems?
4.
What are some of the advantages and disadvantages of industrialised societies?
5.
a)
Distinguish between cornucopianism and environmentalism.
b)
Discuss the difference that you would expect between a cornucopian’s and
an environmentalist’s attitude towards the dwindling population of blue
whales in the world’s oceans.
6.
a)
b)
State what is meant by sustainable development citing a specific example.
Discuss four reasons why human beings are not behaving sustainably. c)
Discuss ways in which Caribbean countries can develop sustainably.
7.
What is environmental sustainability? Discuss several ways in which humans are
making the environment unsustainable for other organisms.
8.
Explain what is meant by the term “environmental law”. Briefly explain the mandate
of NEPA and list some of the activities in which it is currently involved.
LECTURE 2 – Ecology/ ecosystems and energy flow
9.
What is ecology? Using examples distinguish between the biotic and abiotic
structure of the environment.
10.
Define the following: individual, community and population.
11.
What is meant by the following: ecosystem, ecosphere, biosphere, ecotone. What
are the relationships between them?
12.
Is the energy available to do work now the same as it was when the universe was
formed? Explain.
13.
a)
b)
14.
Explain the processes of photosynthesis and cell respiration and discuss their
importance to organisms. Provide summary equations for both processes.
15.
a)
b)
c)
d)
What is an ecological pyramid?
Explain what is illustrated in a pyramid of energy and a pyramid of biomass.
Explain why the pyramid of energy had its characteristic shape.
Define the term “ecological efficiency”.
16.
a)
Define the term “trophic level”
What is thermodynamics?
State the first and second laws of thermodynamics and discuss how they
apply to organisms and ecosystems.
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b)
17.
List and define the various levels of consumers that may be found within an
ecosystem.
What are the implications of the complete removal from an ecosystem of:
a) Photosynthetic plants
18.
b) Primary consumers
c) Secondary consumers
Explain the interaction that occurs in the following feeding relationships:
a) Predator – prey
b) Host – parasite
19.
Discuss the possible effects of introducing a foreign organism into an ecosystem.
What is this form of introduction called?
20.
Differentiate between an autotroph and a heterotroph. How are they important with
regards to the transfer of energy in the ecosystem?
LECTURE 3 – Biogeochemical cycles
21.
What are biogeochemical cycles? Explain their importance to living things.
22.
What is the main source of carbon for living things?
23.
Identify the processes that extract carbon and return carbon to the atmosphere in
the carbon cycle.
24.
What are the three largest reservoirs of carbon?
25.
Developed countries are largely responsible for environmental problems associated
with disturbance of the carbon cycle and should therefore be made to solve the
problems they have created. Discuss this statement giving examples to support
your answer.
26.
Explain the following processes of the nitrogen cycle naming the type of bacteria
that may be involved in each process:





Nitrogen fixation
Nitrification
Assimilation
Ammonification
Denitrification
27.
Explain the benefits that legumes and nitrogen fixing bacteria obtain from their
association.
28.
a)
b)
c)
What are the major steps in the phosphorus cycle?
Discuss ways in which humans are affecting the phosphorus cycle.
Explain why the phosphorus cycle may often be considered as coming to a
dead end.
29.
a)
b)
What are the major steps in the hydrological cycle?
Discuss the importance of trees in named processes of the hydrological
cycle.
Suggest ways in which human overpopulation may affect the water cycle.
How may human’s negative effect on the hydrological cycle be averted?
c)
d)
30.
What is precipitation? List four forms of precipitation.
31.
Explain the processes that purify water in the hydrological cycle.
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LECTURE 4 – Ecosystems and Living Organisms
32.
Use examples to explain what is meant by commensalism, mutualism and
parasitism.
33.
What is competition?
ecosystem?
34.
What is meant by the competitive exclusion principle?
factors restrict an organism’s niche.
35.
Differentiate between the following:
What are the possible effects of competition in an
Discuss how limiting
a)
b)
habitat and niche
fundamental niche and realized niche
a)
State and discuss the four observations of Darwin’s mechanism of
evolution by natural selection as the way in which populations change
over time.
b)
Explain what is meant by specialisation.
37.
a)
b)
c)
What is ecological succession?
To what extent is it important to an ecosystem?
Provide differences between the processes of ecological succession and
evolution?
38.
a)
Differentiate between primary and secondary succession using examples
of each in your response.
Define and give characteristics of climax and pioneer communities?
How do the pioneer communities in primary and secondary succession
differ?
36.
b)
c)
39.
Differentiate between weather and climate.
determine the nature of the biome formed?
40.
State the major characteristics and the general geographical locations of the
following biomes of the earth:








41.
a)
Tundra
Taiga
Temperate deciduous forests
Tropical rainforest
Temperate grasslands
Tropical grasslands / savannahs
Chapparal
Desert
Describe the major characteristics of the following ecosystems and state
how human activities may be affecting each:




b)
Which characteristic(s) of climate
tropical rain forests
mangrove forests
coral reefs
seagrass beds
Explain how and why the destruction of a mangrove forest may impact on
an adjacent coral reef.
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LECTURE 5 – Biodiversity
42.
Differentiate between species biodiversity, genetic biodiversity and ecosystem
biodiversity.
43.
Explain why it is important to maintain biodiversity?
44.
a)
b)
45.
Describe the characteristics of endangered species using examples in your
descriptions.
46.
Discuss ways in which biodiversity can be protected.
47.
Describe the main causes of extinction and endangerment of species?
48.
a)
b)
What is a “threatened species”?
Three main categories of threatened species exist. State these categories
and differentiate between them.
Differentiate between ex situ and in situ conservation providing
advantages and disadvantages of each conservation method.
Provide examples of situations where in-situ conservation would be the more
viable, advantageous conservation option i.e. advantageous to the species in
question. Do the same for ex-situ conservation.
LECTURE 6 – Population ecology
49.
What are the factors that affect the growth rate of populations?
50.
What are the differences between the J-shaped growth curve and the sigmoid
growth curve with respect to patterns of population growth?
51.
Using examples, explain what are density dependent factors and density
independent factors in the regulation of population growth.
52.
What does the term “carrying capacity” mean?
53.
State what the term “environmental resistance” means explaining its role in
population growth.
54.
a)
b)
55.
What is the difference between people overpopulation and consumption
overpopulation?
56.
What are some of the factors affecting the birth rate of the human population?
57.
What are some of the factors affecting the death rate of the human population?
58.
What are some of the ways in which countries can lower their birth rates?
59.
a)
b)
63.
Discuss some of the problems facing urban society?
64.
What are some of the solutions to the problems of urbanisation in Jamaica?
To what does the term “biotic potential” refer?
How may biotic potential differ between species?
What is urbanization?
Differentiate with the aid of examples between “push factors” and “pull
factors” influencing urbanization.
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