Biodiversity

STF1053 BiodiversityOverview of Biodiversity

Biodiversity Definition:

The variety of plants and animals and other living things in a particular area or region.

The range of variation among living things

The richness of species of living organisms

Biodiversity is important because plant and animal species interact and depend upon one another for food, shelter, oxygen, and soil enrichment.

2

Biome

A major ecological community, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment.

For example, the world can be divided into at least five major biomes: aquatic; deserts; forests; grasslands; and tundra.

3

Three levels of biodiversity

Genetic diversity

Variation of genes within species

Species diversity

Variety of species within a region

Ecosystem diversity

All the different habitats, biological communities and ecological processes as well as variation within individual ecosystem

4

Biodiversity Kingdom/Kingdom of Life

History of ClassificationTwo Kingdom SystemThree Kingdom SystemFour Kingdom SystemFive Kingdom SystemSixKingdom SystemAnimaliaAnimaliaAnimaliaAnimaliaAnimaliaProtistaProtistaProtista (Protoctista)Protista (Protoctista)FungiProcaryotae (Monera)EubacteriaPlantaeArcheobacteriaFungiFungiPlantaePlantaePlantaePlantae

5

Table 1: Biodiversity of Kingdoms

Monera (Bacteria)

The most numerous and widespread organisms on earth, composed of prokaryotic organisms

consists entirely of the bacteria - very small one-celled organisms, possess a cell wall

Lack both membrane-bound organells and multicellular forms

Archaebacteria (most ancient) are so different they may belong to separate kingdom

Other groups include cyanobacteria (autotrophic) and eubacteria (heterotrophic)

6

Protista

most ancient eukaryotic kingdom, comprising those eukaryotes that can not be classified in any other kingdoms

best defined as eukaryotes that are not fungi, animals, or plants

body (single-celled-colonial- multicellular)

nutrition (heterotrophic)

7

Paramecium aurelia, a ciliate

Fungi

eukaryotic, heterotrophic, usually multicellular with multinucleated cells, with cell walls

obtain energy by decomposing dead and dying organisms and absorbing their nutrients from them

Some cause diseases (yeast infection,

rusts, and smuts) while others are useful in baking, brewing, as foods, drugs and sources of antibiotics.

8

Plantae

immobile, multicellular eukaryotes

produce their own food by photosynthesis

cells encasted in cellulose cell walls

important source of oxygen, food, clothing/construction materials, pigments, spices, dyes, and drugs (including pesticides)

contain nearly 300,000 species

the most important kingdom

9

Animalia

multicellular, heterotrophic eukaryotes

mobile (at least capable of mobility at some stage during their lives)

cells lacking cell walls

provide food, clothing, fats, scents, companionship, and labour

10

Species Diversity

about 1.7 million species have been described (50,000 vertebrates, 250,000 plants, the rest insects)

Major GroupsNo. sp. (world)No. sp. (Malaysia)%Flowering Plants250,000-300,00012,000-15,0005Orchid17,5001,85010.5Palma2,70038514Rafflesia15746.6Nepenthes714056.3Dipterocarp47029863.4Gimnosperm7428711.7Fern>10,000>1,00010Briophyte15,000??Fungi>120,000??Algae>17,000>1,5008.8

11

Table 2: Flora Diversity in Malaysia

Major GroupsNo. sp. (world)No. sp. (Mal)%Mammals4,0002807Birds9.04070-7608Amphibians & Reptiles10,4844004Termites20,0003,0008.8Moths17,9001,2006.7Butterflies>0.12 mill12,00010Freshwater fish19,0562501.3

12

Table 3: Fauna diversity in Malaysia

Factors that tend to increase diversity

physically diverse habitat

moderate amount of disturbance (fire, storm, etc)

a small variation in environmental condition

high diversity at one trophic level, increasing the diversity at another trophic level

an environment highly modified by life (rich organic soil)

middle stages of succession

evolution

13

Factors that tend to decrease diversity

environmental stress

extreme environments

a severe limitation in the supply of an essential resource

extreme amount of disturbance

recent introduction of exotic species

geographic isolation

14

Changes in level of biodiversity

are based on fossil record, distribution of organisms since 4650 million years ago, but are incomplete

Species diversity and no. of families increased from Cambrian and Pleistocene Periods

Species diversity is higher as latitudes and altitudes increases

In terrestrial habitat, diversity was higher in wet areas

The hot spot for biological diversity is in Tropical Rain Forests

Estimated of 90% species on Earth found in Tropical Rain Forests with only 7% of the total land area (Earth)

Factors like climate, edaphic and topography play major roles in influencing biodiversity through time

15

The importance of Biodiversity

As biological resources that provide human needs (food, shelter, warmth, medicines)

The value of Biodiversity

Determined by 3 main approaches:

consumptive use value (firewood, fodder, meat - consumed directly, not thro market

productive use value (commercial products sold in the market eg. meat, timber, medicinal plants, etc)

non-consumptive use value (intangible values such as option value and existence value)

16

The Economic Value of Biodiversity

Biodiversity = Irreplaceable stock of knowledge (4.5 billion years of evolution)

Diversity = information

Use in medicines only 1 % screened for medical use, generating $10 billion industry, 25% prescription drugs in USA are plant-based

Use in agriculture diversity in crop plants, gene banks, increase variability in yields

Scientific research, tourism

Maintaining habitats, hydrological regulations

Undiscovered species

17

Ecological services of biodiversity

Local ecosystem services (hydrological regulation, soil production, soil protection, nutrient recycling)

Hyderological (water quality and quantity, flood control, stability of river banks, maintenance of coastal zones)

Maintain weather conditions (local & global)

18

19

The ecological services of biodiversity (cont)

LOSSES OF BIODIVERSITY AND THEIR CAUSES

How many species are there?

the number of described species is about 1.7 million;

the total is estimated at about 5 million.

It has taken 4.5 billion years for this biodiversity to evolve, and we are rapidly destroying it.

the natural rate of extinction is estimated at about one species per year, the present rate is estimated at 10,000 times that - about one per hour - and almost all of these losses are caused by human activities

Species diversity

About 1.7 million species has been described:

50,000 vertebrates

250,000 plant

The rest are invertebrates (mostly insects)

20

What are the processes that regulate species diversity?

Chance

random processes of birth, death and migration.

History

correlation through time as a function of reproduction.

If a species was abundant in the near past, chances are that it will be abundant today. Also, progeny tend to cluster near the parents, therefore, we tend to find organisms in "pockets" rather than evenly distributed in space.

Necessity

The laws of growth, competition and interaction.

Different species flourish in different conditions. The number of species that can coexist will depend on how complex the environment is and on how strongly they compete with one another. And, of course, the number of species of herbivores, predators and parasites will depend on the number of plants, prey and hosts.

21

Neutral processes that regulate species diversity

Immigration

Immigration provides a continual source of new diversity for a region. The importance of immigration increases as the size of the area decreases. Some organisms are dispersed much more broadly than others.

Extinction

Extinction of a species or a population will occur due to two reasons:

as a result of accidents (environmental fluctuations)

or because of population interactions (predation, competition)

22

23

24

Loss of biodiversity

In prehistoric times, natural disasters and competition with other species were the main causes.

In historic times, overexploitation and exotic species introductions have caused many extinctions.

Today, the main problems facing wildlife are destruction of habitat and pollution.

Mechanisms for loss of biodiversity

Habitat Loss and Fragmentation (dam, coastal development, forest loss for marginal agriculture & timber harvest)

Introduced species (In Hawaii, some 86 introduced plant species seriously threaten native biodiversity; one introduced tree species has now displaced more than 30,000 acres of native trees)

Over-exploitation of plant and animal species (for food, timber, precious commodity, medicine)

Pollution of soil, water, and atmosphere (due to use of pesticides and detergents)

Global climate change (green-house effect)

Industrial agriculture and forestry (through propagating high yield species/varieties only)

25

MACROCONSUMERS

WASTE

RAW

ECOSYSTEM

MATERIALS

SERVICES

MICROCONSUMERS

PHOTOSYTHETIC

PRODUCERS

NUTRIENTS

SUNLIGHT

MACROCONSUMERS

WASTE

RAW ECOSYSTEM

MATERIALS SERVICES

MICROCONSUMERS

PHOTOSYTHETIC

PRODUCERS NUTRIENTS

SUNLIGHT

Table 4. Recorded Extinctions, 1600 to 1983

Mainland

a

Island

b

Ocean Total

Approximate

Number

of species

Percentage of

Taxa Extinct

Since 1600

Mammals

30 51 2 83 4,000 2.1

Birds

21 92 0 113 9,000 1.3

Reptiles

1 20 0 21 6,300 0.3

Amphibians

2 0 0 2 4,200 0.0

Fish

c

22 1 0 23 19,100 0.1

Invertebratesc

49 48 1 98 1,000,000+ 0.0

Vascular Plants

d

245 139 0 384 250,000 0.2

Total

370 351 3 724

a. Landmasses greater than 1 million square kilometers (the size of Greenland and

larger).

b. Landmasses less than 1 million square kilometers.

c. Totals primarily representative of North America and Hawaii.

d. Vascular taxa (includes species, sub species, and varieties).

Table 4. Recorded Extinctions, 1600 to 1983

Mainland a

Island b

Ocean

Total

ApproximateNumberof species

Percentage ofTaxa ExtinctSince 1600

Mammals

30

51

2

83

4,000

2.1

Birds

21

92

0

113

9,000

1.3

Reptiles

1

20

0

21

6,300

0.3

Amphibians

2

0

0

2

4,200

0.0

Fishc

22

1

0

23

19,100

0.1

Invertebratesc

49

48

1

98

1,000,000+

0.0

Vascular Plantsd

245

139

0

384

250,000

0.2

Total

370

351

3

724

a. Landmasses greater than 1 million square kilometers (the size of Greenland and larger).b. Landmasses less than 1 million square kilometers.c. Totals primarily representative of North America and Hawaii.d. Vascular taxa (includes species, subspecies, and varieties).

Table 5. Number of Endangered and Extinct Animal Species

compiled from the IUCN's Red List, 1996

From Fact Sheets - Rainforest Action Network

class

critically

endangered

endangered

vulnerable

total threatened extinct

Mammals 169 315 612 1096 89

Birds 168 235 704 1107 108

Reptiles 41 59 153 253 21

Amphibians 18 31 75 124 5

Insects 44 116 377 537 73

Other animals 471 423 1194 2088 343

Table 5. Number of Endangered and Extinct Animal Speciescompiled from the IUCN's Red List, 1996From Fact Sheets - Rainforest Action Network

class

critically endangered

endangered

vulnerable

total threatened

extinct

Mammals

169

315

612

1096

89

Birds

168

235

704

1107

108

Reptiles

41

59

153

253

21

Amphibians

18

31

75

124

5

Insects

44

116

377

537

73

Other animals

471

423

1194

2088

343