West Visayas State University/2020

NCSI 111 (People and the Earth’s Ecosystem)

Lesson 15: Anthropogenic Impact: Biodiversity Loss

[Week 15]
Introduction:
The biosphere which is the world of life is the region of the earth’s surface
where all living things live and interact with one another. Variations lead to richness
of biodiversity and this richness in biodiversity leads to ecological stability in an area.
A change in biodiversity richness and evenness is an indicator that some species are
disappearing and may soon become extinct if existing traits cannot adapt to the
changing environment.
How do we contribute to the loss of biodiversity? What actions are made by
community, government, and civic organizations to protect and conserve biodiversity

PRIOR TO THE LESSON

Pre - Assessment

Fill in the table below to assess your prior knowledge about Biodiversity Loss.
You will fill up the column for What Did I Learn at the end of the lesson.

K W H L
What do I know What do I want to How can I find out What did I learn
find out what I want to
learn

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Review

Answer the questions briefly.

 Differentiate greenhouse effect from global warming and climate
change
 How can you help minimize the effects of global warming?

Feedback

 Answer will vary

 Greenhouse effect is the increase of greenhouse gases that traps more
heat from the earth’s surface. This will result to increase in atmospheric
temperature that affects our climate
 Ex. Lessen your carbon footprint

Motivation

Open this link https://www.youtube.com/watch?v=2F2KzjTzi9Q .

Question:
Why is our country a mega diverse terms of biodiversity?

NEW LESSON

Biodiversity is a term used to describe the enormous

variety of life on Earth. It can be used more specifically to
refer to all of the species in one region or ecosystem. It
refers to every living thing, including plants, bacteria,
animals, and humans. Scientists have estimated that there
are around 8.7 million species of plants and animals in existence. However, only

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around 1.2 million species have been identified and described so far, most of which
are insects. This means that millions of other organisms remain a complete mystery.
Biodiversity varies in terms of geographical location, which is said to be high in
the tropics but decline to poles due to amount of sunlight. On the other hand it
constitutes the most important working component of a natural ecosystem. It helps
maintain ecological processes, creates soils, recycles nutrients, has a moderating
effect on the climate, degrades waste, controls diseases and above all, provides an
index of health of an ecosystem. Providing food, medicines and a wide range of
useful products, it is the natural wealth that exists on land, in freshwater and in the
marine environment. Plant diversity alone offers more than just food security and
healthcare for the one-quarter of humanity who live their lives at or near subsistence
levels; it provides them with a roof over their heads and fuel to cook, and, on
average, meets 90 per cent of their material needs.
There are kinds of biodiversity that are essential to preserve ecological
systems and functions.
1. Genetic diversity – a measure of the variety of different versions of the same
genes within individual species. When species reproduce, the genes of each
mate contribute to the characteristics of the progeny. Accordingly, no two
members of the same species are exactly alike.

Domestic
cat breeds

2. Species diversity - the number of different

species within individual communities or
ecosystem.
3. Ecological diversity -
the number and
variability of
ecosystems in an area
including the number

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of niches, trophic levels, and ecological processes that

capture energy, sustain webs, and recycle materials within this ecosystem.
How many species are there?
The 1.4 million species presently known probably represent a small fraction of
the total number that exist [table 1]. Based on the rate of new discoveries by
research expeditions especially in the tropics taxonomists estimate that somewhere
between 3 million and 5 million different species maybe alive today. In fact, there
may be 30 million species of tropical insects alone. About 70% of all known species
are invertebrates.

Approximate Numbers of Known

Living Species of Taxonomic Group

The majority of identified endangered species are birds, mammals and amphibians.
a. What proportion of all known species do these three groups represent?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________

b. How might you explain this disproportionate listing?

_______________________________________________________________
_______________________________________________________________
_______________________________________________________________

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Activity
Activity 15.1

There are many ways of measuring biodiversity. Two of them are species
richness and species evenness. Species richness refers to the number of species in a
particular place. This is the most common type of biodiversity index. Another way is
species evenness which refers to the extent to which individuals are distributed
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evenly among species. It gives information about the relative quantities or proportion
of individuals belonging to different species.
Biodiversity Hotspots
Biodiversity is not evenly distributed. It is richer in the tropics and other
localized regions. Several factors affect the diversity of flora and fauna. These are
climate, altitude, soil
and presence of
other species. Large
numbers of them are
formally classified as
rare or endangered
or threatened
species.
Most of the
world’s diversity is
concentrated near
the equator,
especially tropical rain forest and coral reefs. Only 10 to 15% can be found in
America and Europe.
Areas isolated by water, deserts or mountains can also have high
concentrations of unique species and biodiversity.
The hotspots collectively make up 1.4% of the earth’s land but contain as
many as 44% of all vascular plant species, 29% of the world’s endemic birds species,
27% of endemic mammal species, 38% reptile species and 53% of endemic
amphibians species.
How do we benefits from biodiversity?
We benefit from other organisms in many ways, some of which we don’t
appreciate until a particular species or community disappears.
1. Food
Many wild plants species could make important contribution to human food
supplies either as they are or a source of genetic material to domestic crop. Noted
tropical ecologist Norman Myers estimates that as many as 80, 000 edible wild plants
species could be utilized by humans. On the other hand, many kinds of animals are
utilized as foods; however most consumption is focused on a few species only.

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2. Drugs and medicines

Living organisms provide us with many useful drugs and medicines [table 2]. More
than half of all prescriptions contain some natural products. The United Nations
Development Programme estimates the value of pharmaceutical products derived
from developing world plants, animals and microbes to be more than $30 B per year.
Product Source Use
Penicillin Fungus Antibiotic
Bacitracin Bacterium Antibiotic
Tetracycline Bacterium Antibiotic
Digitalis Foxglove Heart stimulant
Quinine Chincona bark Malaria treatment
Cortisone Mexican yam Anti inflammation treatment
Vinblastine, vincristine Periwinkle plant Anti cancer drug
Bee venom Bee Arthritis relief
Allantoin Blowfly larva Wound healer
Cytarabine Sponge Leukemia cure

3. Ecological benefits

Soil formation, waste

disposal, air and water
purification, nutrient cycling,
solar energy absorption and
food production all depend on
biodiversity. In many
environments, high diversity
may help biological communities
withstand environmental stress
better and recover more quickly
than those with fewer species.
In addition, it is estimated that
Source: www.haribonfoundation.com.org
95% of the potential pests and disease
carrying organisms in the world are controlled by natural predators and competitors.
4. Aesthetic and cultural benefits
Millions of people enjoy nature based activities like hunting, fishing, camping,
hiking and wildlife watching. Thus, many communities are finding that local
biodiversity can bring cash to remote areas through ecotourism. The activities
provide invigorating physical exercise, and contact to nature can have psychological

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and emotionally restorative. In many cultures, nature carries cultural connotations

and a particular species or landscape may be inextricably linked to a sense of identity
and meaning.
What threatens biodiversity?
Biological diversity is currently decreasing at an alarming rate and this could
result to biodiversity loss. Loss of biodiversity refers to either the ongoing extinction
of species at a global level or the local reduction or loss of species in a given
habitat. The scale of the problem: in the last 40 years, we have lost 52% of
planetary biodiversity and lost 58% of vertebrates on land, sea and air - the
vertebrate figure could rise to 66% by 2020.
1. Habitat loss and fragmentation
A habitat is the place where a plant or animal naturally lives. Habitat loss is
identified as main threat to 85% of all species described as threatened or
endangered. In addition to loss of habitat area is habitat fragmentation – the
reduction of habitat into smaller and smaller scattered patches. It reduces
biodiversity because many species require large territories to exist. Other species
such as forest interior birds reproduce successfully only in deep forest or other
habitat far from human settlement.
Fragmentation also divides populations into isolated groups. Small isolated
populations are vulnerable to catastrophic events, such as a single storm or disease
outbreak. Very small populations may not be enough breeding adults to be viable
even under normal circumstances.
2. Over – exploitation for commercialization
Over exploitation of resources has coasted more environmental degradation
than earning. For example shrimp farming in Thailand results in wetland destruction,
pollution of coastal waters and degradation of coastal fisheries. Scientific studies
show that environmental degradation from shrimp farming cost more than the
earning through shrimp exports
3. Invasive species
Invasive species are “alien” or “exotic species which are introduced
accidentally or intentionally by humans. They can be thought of a biological pollution.
Freed from predators, parasites, pathogens and competition that kept them in check,
in their native home, formerly mild mannered species can turn into super aggressive
“weedy’ invaders in a new habitat.

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A B

4. Pollution
One of the most difficult problems to overcome since pollutants does not
recognize international boundaries. We have known that toxic pollutants can have
disastrous effects on local population of organisms. Pollutants like DDT, PCB’s and
dioxins in fat can weaken the immune systems that make animals vulnerable to
infections.

Sources of pollution Source:

Microsoft Encarta

5. Global climate change

Many climatologists believe that the greenhouse effect is likely to raise world
temperatures by about 2 oC by 2030 meaning the sea level will rise by around 30 –
50 cm by this time. Global warming plus human population growth and accelerating
resource use will bring further losses in biological diversity.
6. Population growth and over consumption
From a population of 1 billion at the beginning of 19th century, human population is
now more than 6 billion. Such rapid population growth has meant a rapid increase in
the exploitation of natural resources – water, land and minerals. 25% of the
population consumes 75% of the world’s natural resources.
7. Illegal wild life trade
Recreational hunting and collecting: hides, skin, tusk, meat, fur, chemical
content taken for monetary or aesthetic value or simply ego in the case of hunting
with no purpose other than the thrill of the kill. In the last decade, over one third of
African elephants have been killed by hunters and poachers to fuel the ivory trade.

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Fashion: fur clothing and reptile skins for bags and accessories are just two of
the more obvious fashion-driven pressures on the natural world.
Medicinal or traditional medicinal demand: traditional medicines often drive
significant demand for animal and plant material which can only be obtained by
killing the providing life form. For example, Rhino horn is highly prized in Asian
cultures for its claimed medicinal properties.

8. Species extinction
Extinction is a natural process. The geological record indicates that many
hundreds of thousands of plant and animal species have disappeared over the eras
as they have failed to adapt to changing conditions. Recent findings however indicate
that the current rate of species extinction is at least a hundred to a thousand times
higher than the natural rate.
The International Union for Conservation of Nature [IUCN], assessed 44, 838
animal species all over the globe and came out with a red list of threatened species.
The red list gives an inventory of the global conservation status of threatened
species. Of this number, 3,246 are critically endangered, 4,770 are endangered and
8, 912 are vulnerable to extinction. In the Philippines, the Philippine eagle tops the
‘red list’ among the critical endangered species with only 180 to 500 mature
Philippine eagles left in the wild and in captivity. Other endemic Philippine species
included in the list include the Cebu flowerpecker, Philippine cockatoo, Philippine
crocodile, Visayan warty pig and Tamaraw. By the numbers

 75%: terrestrial environment “severely altered” to date by human actions

(marine environments 66%).
 47%: reduction in global indicators of ecosystem extent and condition against
their estimated natural baselines, with many continuing to decline by at least
4% per decade.
 28%: global land area held and/or managed by Indigenous Peoples ,
including >40% of formally protected areas and 37% of all remaining
terrestrial areas with very low human intervention.
 +/-60 billion: tons of renewable and non-renewable resources extracted
globally each year, up nearly 100% since 1980.

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 15%: increase in global per capita consumption of materials since 1980.

 >85%: of wetlands present in 1700 had been lost by 2000 – loss of wetlands
is currently three times faster, in percentage terms, than forest loss.

The staggering rate of irreversible biodiversity loss around the globe holds
serious consequences for medicine and public health.
1. Loss of potential medicine
Traditional medicines continue to play an essential role in health care, especially
in primary health care. Traditional medicines are estimated to be used by 60% of the
world’s population and in some countries are extensively incorporated into the public
health system. Medicinal plant use is the most common medication tool in traditional
medicine and complementary medicine worldwide
2. Nutritional impact
Biodiversity plays a crucial role in human nutrition through its influence on
world food production, as it ensures the sustainable productivity of soils and
provides the genetic resources for all crops, livestock, and marine species
harvested for food. Access to a sufficiency of a nutritious variety of food is a
fundamental determinant of health.
3. Infectious diseases
Human activities are
disturbing both the structure and
functions of ecosystems and
altering native biodiversity. Such
disturbances reduce the
abundance of some organisms,
cause population growth in
others, modify the interactions
among organisms, and alter the
interactions between organisms
and their physical and chemical
environments. Patterns of infectious diseases are sensitive to these disturbances.

Major processes affecting infectious disease reservoirs and transmission include,

deforestation; land-use change; water management e.g. through dam

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construction, irrigation, uncontrolled urbanization or urban sprawl; resistance to

pesticide chemicals used to control certain disease vectors; climate variability and
change; migration and international travel and trade; and the accidental or
intentional human introduction of pathogens.
4. Climate change, biodiversity and health
Biodiversity provides numerous ecosystem services that are crucial to
human well-being at present and in the future. Climate is an integral part of
ecosystem functioning and human health is impacted directly and indirectly by
results of climatic conditions upon terrestrial and marine ecosystems. Marine
biodiversity is affected by ocean acidification related to levels of carbon in the
atmosphere. Terrestrial biodiversity is influenced by climate variability, such as
extreme weather events (i.e. drought, flooding) that directly influence ecosystem
health and the productivity and availability of ecosystem goods and services for
human use. Longer term changes in climate affect the viability and health of
ecosystems, influencing shifts in the distribution of plants, pathogens, animals,
and even human settlements.
Important Actions to protect biodiversity loss
1. Protect habitats
2. Control invasion of foreign species. Introduction of foreign species not native
in the area can upset the balance among organisms in that area. They can
prey on native species or compete with them for food or space.
3. In Situ conservation. These are areas or regions that are made into national
parks, marine sanctuaries, wildlife refuges and other protected areas by law.
This will ensure that plants and animals in these regions are preserve and
protected.
4. Restore damage habitat
5. Wildlife farms. They take away pressures from hunting some endangered
species such as crocodiles by raising the in numbers and commercially selling
their parts
6. Conservation organization. Examples are the World Wide Fund for Nature,
Biodiversity Conservation Network and International Union for Conservation
of Nature and Natural Resources.
7. International treaties and national government laws and policies

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a. Convention on International Trade and Endangered Species [CITES] ban

the hunting, capturing and selling of threatened or endangered species
b. Convention on Biological Diversity [CBD]
c. Philippine Endangered Species Act [RA 9147] known as Wildlife Resources
Conservation and Protection Act.

Activity

Activity 15.2: What you can do

Upon learning about the importance of biodiversity, list 5 simple ways that
you can do to prevent their loss.
1. ________________________________

2. ________________________________

3. ________________________________

4. ________________________________

5. ________________________________

Activity

Activity 15.3

Open this website https://www.youtube.com/watch?v=gxqgm-ruiW8

and watch this documentary film entitled Philippine Seas. Afterwards answer the
following questions below.
1. What is the purpose of doing this documentary film?
_______________________________________________________________
_______________________________________________________________
2. Make a short reflection about the status and the problems of the country’s
aquatic biodiversity.
__________________________________________________________________
__________________________________________________________________

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SUBSEQUENT TO THE LESSON

Summary

Different biomes shelter the world’s diversity. We human benefit from

biodiversity in many ways, but we also threaten biodiversity through land conversion
and other activities. Among the threats are overharvesting of plants and animals for
food and commercial products. Millions of plants and animal are collected for pets,
houseplants and medical research. Among the greatest damage we do to biodiversity
are habitat destruction, introduction of exotic species and pollution.
The potential value of the species that may be lost if environmental
destruction continues could be enormous. It is also possible that changes we are
causing could disrupt vital ecological services on which we all depend for life.
As we gradually become aware of how serious biodiversity loss has become,
we are adopting laws and treaties to protect these irreplaceable assets.

Reflection:

Open this link https://youtu.be/0Zk1inP2Td4 and reflect on this song “What

a Wonderful World”

Post Assessment

Direction: Encircle the letter of the correct answer.

1. How do ecologists define biodiversity?
A. Whole variety of life on earth
B. A group of plants and animals that live in an ecosystem
C. Region of earth where all organisms live and interact
D. Richness and complexity of a biological community

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2. Which is not the role of our government in conserving our country’s diversity
A. Receive incentives from land owners
B. Pass laws to provide effective protection for species and habitat
C. Provide limited incentives for private investments in biodiversity
conservation
D. Conduct checkpoint to ensure that endemic organisms cannot be
transported illegally
3. Which is the best measure of biodiversity? The
A. temperature and precipitation in an area
B. Number of different organisms in an area
C. Number of species in an area
D. None of the above
4. This medicine is derived from periwinkle plant or “Rosas de Baybayon?”
A. Coumadin B. Morphine C. Vincristine D. Aspirin
5. Bohol, Philippines is known for its wide variety of endemic animals that
makes it more attractive to tourists. Which value of biodiversity is describes
below?
A. agriculture
B. recreation and tourism
C. research and education
D. Spiritual and cultural
6. Which does not belong to the group?
A. Philippine eagle C. Palawan peacock peasant
B. Visayan spotted deer D. maya
7. This policy ensures to conserve our country’s wildlife resources and their
habitat
A. RA 9147 B. RA 8749 C. RA 9275 D. RA 9003
8. The following are illegal acts against biodiversity except
A. Hunting
B. Trading of wildlife
C. Dumping of waste products detrimental to wild life
D. Support the World Wide Fund for Nature

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9. The world’s diversity is concentrated near the equator. Which of the following
factor can explain this?
A. Temperature B. amount of sunlight C. precipitation
D. all of the above
10. Species diversity can be conserve by
A. Protection of habitat
B. Buying products from endangered species
C. Keeping exotic pets
D. Collecting wild plants

References

Biodiversity and Well Being [2006] retrieved from:

https://www.greenfacts.org/en/biodiversity/
Cadiz, Arlon P., Macasil, Trinidad D. (2015) Environmental Science: Modular
Approach, Mindshapers Co. Inc.
Cunningham, William P,Cunningham, Mary Ann (2008) Principles of Environmental
Science: Inquiry Approach . The McGraw Hill Companies.
Importance of Biodiversity [2008]. Retrieved from
https://opentextbc.ca/conceptsofbiologyopenstax/chapter/importance-of-
biodiversity/
Mosteiro, Arnaldo P. (2012) Environmental Science: Protect Our Planet, Educational
Publishing House
Save Earth: Loss of Biodiversity [2010].Retrieved from
https://www.saveearth.info/loss-of-biodiversity/
Shah, Anup [2014] Why is Biodiversity Important? Who Cares? Retrieved from:
https://www.globalissues.org/article/170/why-is-biodiversity-important-who-
cares
UN Report: Nature’s Dangerous Decline “Unprecedented”. Species Extinction Rate
‘Accelerating’ [2019]. Retrieved from:
https://www.un.org/sustainabledevelopment/blog/2019/05/nature-decline-
unprecedented-report/

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