CONSERVATION AND BIODIVERSITY 4.1 Biodiversity in ecosystems.

CONSERVATION AND BIODIVERSITY

4.1 Biodiversity in ecosystems

Assessment Statements

4.1.1 Define the terms biodiversity, genetic diversity, species diversity, and habitat diversity

4.1.2 Outline the mechanism of natural selection as a possible driving force for speciation.

4.1.3 State that isolation can lead to different species being produced that are unable to interbreed to yield fertile offspring.

4.1.4 Explain how plate activity has influenced evolution and biodiversity.

4.1.5 Explain the relationships among ecosystem stability, diversity, succession and habitat.

4.1.1 Define the terms biodiversity, genetic diversity, species diversity, and habitat diversity

Biodiversity: amount of biological or living diversity per unit area. Consists of species, habitat, and genetic diversity

Genetic Diversity: Different genetic characteristics of a species.

Cheetah populations have very low diversity, due to inbreeding

4.1.1 Define the terms biodiversity, genetic diversity, species diversity, and habitat diversity

Species diversity – the variety of species per unit area; includes the number of species present and their relative abundance.

4.1.1 Define the terms biodiversity, genetic diversity, species diversity, and habitat diversity

Habitat Diversity: The amount of habitats or niches in a given area Variety of forests, deserts, grasslands,

lakes, oceans, coral reefs, wet lands, and other biological communities.

Chaparral Coniferous forest dessert grasslands deciduous forest

Biodiversity: Why should we care?

Diverse ecosystems are more stable and more healthy

More resistant to damage from factors like climate change and spread of disease

Provides important ecological services to humans

Biodiversity is useful to us as humans Recreation Food Goods Medicine

Ecological Services of Biodiversity

Flow of material, energy in the biosphere Photosynthesis Pollination Soil formation and

maintenance Nutrient cycling Moderation of weather

extremes Purification of air and

water

Important “stuff” From biodiversity Food, fuel, ecosystems, species, fiber,

lumber, paper…. 90% of all food crops 40% of all medicines and 85% of all

antibiotics

Pacific Yew – Taxol (cancer drug)

Willow Tree - Aspirin

Biodiversity of Species

Each Species and Process…

Is key to the overall function of earth In general Diversity = Stability Biodiversity is

Nature’s insurance policy against change The source of all natural capital for human

use The way chemical materials are cycled and

purified The end result of millions of years of

evolution and irreplaceable

Mexico

Brazil

Madagascar

South Africa

Australia

Indonesia

Philippines

India

China

EcuadorColombia

Costa Rica

Peru

Venezuela

CameroonZaire

Ethiopia

Myanmar

Malaysia

The 19 Most Biodiverse countries in the world.What is the Problem with this?

Polynesia andMicronesia

islandcomplex

Mediterraneanbasin

Caribbean

WesternGhats andSri Lanka

Philippines

Wallacea

NewCaledonia

TropicalAndes

CentralChile

BrazillianCerrado

Caucasus

Eastern Arc Mountainsand coastal forests

of Kenya and Tanzania

Cape Floristicregion of

South Africa

SucculentKaroo

Madagascar/Indian Ocean

islandsSouthwestAustralia

New Zealand

Polynesiaand

Micronesiaisland

complexIndo-Burma

Mountains of southcentral China

Guineanforests of

WestAfrica

Brazil'sAtlanticforests

Sundaland

Choco/Darien/western Ecuador

CaliforniaFloristicProvince

Meso-americanforests

Biodiversity Hotspots need special consideration

Hotspots

These areas need emergency conservation attention

Especially rich in endemic plant and animal species (found nowhere else in the world)

They cover on 1.4% of world land area Mostly tropical forests Contain 60% of identified terrestrial biodiversity 55% of all primates, 22% of all carnivores 1.1 billion people living in poverty near these

sites $500 million annually would go far to ensure

their preservation

Diversity includes

1. Richness: The number of species per sample is a measure of richness.

The more species present in a sample, the “richer” the sample.

2. Evenness: A measure of the relative abundance of the different species making up the richness of an area.

Which sample is more diverse?Flower Species Sample 1 Sample 2

Daisy 300 20

Dandelion 335 49

Buttercup 365 931

Total 1000 1000

Which has a higher richness? Evenness?

Quantifiying this Diversity – Simpson’s Index

D = N (N – 1)∑ n (n – 1)

Where D = diversity index N = total # of organisms of all species n = # of individuals of particular

species

Now practice the simpson’s index

Species Number (n) n (n – 1)

Woodrush 2

Holly seedlings 8

Bramble 1

Yorkshire Fog 1

Sedge 3

Total (N)

Now practice the simpson’s index

Species Number (n) n (n – 1)

Woodrush 2

Holly seedlings 8

Bramble 1

Yorkshire Fog 1

Sedge 3

Total (N) 15

Now practice the simpson’s index

Species Number (n) n (n – 1)

Woodrush 2 2

Holly seedlings 8 56

Bramble 1 0

Yorkshire Fog 1 0

Sedge 3 6

Total (N) 15 64

15(14) / 64 =3.28

High values of “D” suggests a stable and ancient site

A low value of “D” could suggest pollution, recent colonization, or agricultural management

Index normally used in studies of vegetation but can be applied to comparisons of diversity of any species

How does diversity exist?

Natural Selection = survival of the fittest Fitness = a measure of reproductive success

If all individuals are variable And populations produce large numbers of

offspring without increase in population size And resources are limited And traits are heritable

How does diversity exist?

Those individuals who are best adapted to the environment will survive and pass on their genes

Gradually the gene frequency in the population will represent more of these “fit” individuals