Lawal M. Marafa, Ph.D Ecosystem and Biodiversity: Human Impacts and Conservation in HK A–Level...

Lawal M. Marafa, Ph.D

Ecosystem and Biodiversity: Human Impacts and Conservation in HK

A–Level Geography Seminar

OUTLINE:

Ecosystem

Biodiversity (In HK)

Conservation

Human Impact

The Case of HK

Ecosystem, Biodiversity and Conservation (HK)

The ecosystem

Ecosystem: is an energy-driven complex of a community of organisms and its controlling environment;

…..an ecological unit composed of living and non-living components interacting to produce a stable system;


Hierarchy

Organisms occur in populations, members of the same species that live together in the same area at the same time.

Ecosystem: hierarchical way to view the living organisms in the biosphere on earth

The ecosystem


is a classical example of an environmental system because it has the qualities of a functional system.

The ecosystem


Producers

Decomposers

Consumers

Three important qualities: a) the system is made up of component

parts, b) the parts work together, and c) the whole thing serves some purpose

The ecosystem


How does the ecosystem work?

Energy flows Nutrients cycle

The ecosystem


To summarize, energy enters the ecosystem as free, solar energy and leaves it as heat, having undergone changes from a ‘concentrated’ to a ‘dispersed’ state.

The ecosystem


Potential

Kinetic

The earth’s ecosystems are grouped into biomes characterized by particular plant and animal types, usually named for a region’s climate or dominant vegetation.

The ecosystem


So biomes contain many ecosystems (species)

The ecosystem


Darwin’s Theory of Evolution and

Survival of Species

What is a species? a population whose members are able to interbreed freely under natural conditions


Scientists can often trace the evolution of a complete group of species by looking at fossils.

Elephants (proboscideans) includes more than 150 species now extinct.

As time went by, their tusks, trunks, and bodies became larger.

Evolution of species


Finches

Evolution: a process of continuous change from a lower, simpler, or worse to a higher, more complex, or better state.

Evolution of speciesEcosystem, Biodiversity and

Conservation (HK)

appearance (morphology)appearance (morphology)

internal processes (physiology)internal processes (physiology)

ecological preferencesecological preferences

Evolution of species

Most organisms can be classified into distinct groups on the basis of their:

New species appear by mutation


the diversity of species present in any environment characterizes

a biome

Biomes represent the powerhouse of biodiversity

These variations and traits lead to biodiversity

Variation exists within species


Biodiversity can improve the stability of an entire community (ecosystem)

The maintenance of a healthy biodiversity is the function of plants, soils, climates, and indeed human activity


So what is Biodiversity?

The variation among organisms is referred to as biological diversity

Biodiversity, therefore, encompasses all species of plants, animals, and micro-organisms and the ecosystems and ecological processes of which they are part.


Biodiversity is usually considered at three different levels:

1. Genetic diversity,

2. Species diversity, and

3. Ecosystem diversity.

So what is Biodiversity?


Genetic Diversity

total of genetic information, contained in the genes of individual organisms

This is now the age of the DNA!!


Dolly

Variation in shell colour and banding patterns among populations of one species of snail

Genetic Diversity


Variation in corn

Ecosystem Diversity Relates to the variety of habitats,

biotic communities, and ecological processes in the biosphere,

as well as the tremendous diversity within ecosystems in terms of habitat differences


Species Diversity the variety of living

organisms on earth (variously estimated to be between 5 and 50 million)

only about 1.4 million have actually been described


the sustainability and well-being of human beings relies on biodiversity;

the best illustration is the development of human civilization;

several important events (agriculture):


The Importance of Biodiversity

Food

there are 7500 kinds of eatable plants. Only approximately 150 are agriculturally planted by man.

approx. 90% of food sources comes from about 20 crop species. Only wheat, rice and corn make up 70%



In some developing countries, wildlife is the main source of protein

Merchandise

Drugs

Fuel

Tourism and recreation and so on




Organisms also provide recreation, inspiration, and spiritual solace;

The belief that all organisms have the right to exist and that humans should not cause the extinction of other organisms is known as deep ecology.

Aesthetic and Ethical Values



biological diversity is valued by Judeo-Christian religions as evident in the story of Noah’s Ark

(which is considered to be the first “endangered species conservation project”)

Religious Values


BiodiversityHow much biodiversity is there?

1.4 million species have been described270,000 flowering plants950,000 insects40,000 are vertebratesmajority are small and inconspicuous &

unknown to scienceGlobal Total Species Number

(5 to 50 million)


Biodiversity

Each of the species has a specific habitat needs, occupying specific ecological niche


Bat

Swallow

Biodiversity trends

Over Geologic and Historical Timenew species appeared (speciation)species disappeared (extinction)


Biodiversity

Current Diversity: less than would have been present in the past, due to human impact

Past - elephants, tigers, rhinoceroses, gibbons, woodpeckers, etc..


Indian Tiger Black Rhino

African Elephant Asian or Indian Elephant


Loss of Biodiversity

Extinct worldwide about - 484 animal and 654 plant species

In danger of becoming extinct - 5400 animal & 26,000 plant species

example: Tropical rainforest - the richest and most diverse, now clearing at 1.8% p.a.


Biodiversity (in HK)

HK is amazingly species-richmore species than whole of Britain in all groups460 birds (as compared to 1200 in China)21 bats (only 30 in whole Europe)211 butterflies, 104 dragonflies, 73 reptiles, 53

mammals, 22 frogs, 1900 flowering plants23 amphibians (51 in Guangdong)



Some species are endemic - occur no where else, e.g. Romer’s tree frog

Some globally endangered species - Black-faced spoonbill (Mai Po Ramsar Site)


Country Parks - good coverage of vascular plants Marine Parks – good protection of aquatic

resources

SSSI - species rich, but not under active management, little protection

These promotes conservation (in situ and ex situ)



Threat to Biodiversity in Hong Kong


Urbanization & Infrastructure Building - particularly in NT

Abusive Fishing Practices - explosives and cyanide fishing

Hill fire

Reasons for Decline in Biodiversity

Physical Alteration of Habitatsconversion fragmentationsimplification

Population Factor - hunting Pollution - DDT, marineIntroduction of Exotic Species, etc.


Consequence of Losing Biodiversity

Life goes on in spite of extinctionDon’t bother, it has happened in geological past

Ecosystem Function - major ecosystem processes will be affected!!


Consequence of Losing Biodiversity

Example:Succession

"a continuous process of change in vegetation which can be separated into a series of phases"

non-seasonal, directional change


Biodiversity conservation protection

Destruction of biodiversity is directly protected by two types of law:

those which protect areas;

those which protect species;


The Laws of Protection:

- Country Parks Ordinance was formed in 1976

- To date more than 41000 ha have been designated as 23 Country Parks

SSSIs

The protection of Endangered Spp. Ordinance Wild Animals Protection Ordinance Marine Park Ordinance



On the international front, there are:

Convention on International Trade in Endangered Spp. of Wild Fauna and Flora

Ramsar Convention



Convention on biological diversity

Finally,

Plants, animals and insects survive not because they

are the biggest or strongest but because they can adapt

to the changing environment…….


Indeed, "The world exists for its own sake, not for ours. Swallow

that pill!" --Edward Abbey

Lawal M. Marafa, Ph.D Ecosystem and Biodiversity: Human Impacts and Conservation in HK A–Level...

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