Download Topic 4 Notes - rufuskingenvironmentals

4.1 –
Biodiversity in
Ecosystems
IB Topics 2.1.1-2.1.7
Biodiversity
 Species
Diversity
 The variety of
species per unit area
 High species diversity
= More complex
Biodiversity
 Habitat
Diversity
 The range of
different habitats in
an ecosystem
 High habitat diversity
= more niches
Biodiversity
 Genetic
Diversity
 The variety of genes
present in a species
 High genetic
diversity = Better
survival
Biodiversity Hotspots
 Areas
of high biodiversity
Natural Selection
 New
species arise through natural selection
 The fittest organisms survive and have more offspring,
changing species over time
Isolation and Natural Selection
 Isolation
leads to speciation
(forming new species)
 Isolation:




Fences/roads/deforestation
Deserts
Rivers
Islands
Plate Tectonics and
Speciation
 Movement
of tectonic
plates creates
mountains, oceans,
valleys, islands
 This leads to speciation
 Ex:
4.2 – Evaluating
biodiversity and
vulnerability
IB Topics 2.1.1-2.1.7
Extinction
 Extinct

No members of a
species remain
 Extinct

in the wild
No members of a
species remain in the
wild
 Extirpated

Locally extinct
Mass Extinctions
5
major mass
extinctions
 Up to 75% of all
species went
extinct
Sixth Mass Extinction
 Countless
extinctions
over the past 10000
years
 Climate change &
Humans
Extinction Rate
 Believed
to be 10-100
species per year
throughout natural
history
 Now believed to be
much higher

89 mammals over the
past 400 years
Rainforests
 Have
the highest
biodiversity on Earth


50% of all plant and
animal species
Make 40% of Earth’s
oxygen
Rainforest Loss
 Up
to 1.5 hectares
cleared per second

Ranching &
Logging
 Growing
population
living in the
rainforest
Factors that make species
prone to extinction:
 Small
Population Size
 Limited Distribution
 Specialists
 Low Reproductive
Capacity
 Poor Competitors
 Large Mammals
 Valuable Products
 Altruistic Species
IUCN Red List
 International
Union for
the Conservation of
Nature
 Red List:

An inventory of all
threatened species
Determining Conservation
Status
 Population
size
 Reduction in
population size
 Geographic range
 Quality of habitat
 Probability of
extinction
Natural Factors that lead to loss of
biodiversity
 Natural
Disasters
 Environmental
Disasters
 Habitat
Fragmentation
 Pollution
Human Factors that lead to loss
of biodiversity
 Overexploitation
 Invasive
Species
 Disease
 Modern
Agricultural
Practices
Factors that make species
prone to extinction:
 Small
Population Size
 Limited Distribution
 Specialists
 Low Reproductive
Capacity
 Poor Competitors
 Large Mammals
 Valuable Products
 Altruistic Species
IUCN Red List
 International
Union for
the Conservation of
Nature
 Red List:

An inventory of all
threatened species
Determining Conservation
Status
 Population
size
 Reduction in
population size
 Geographic range
 Quality of habitat
 Probability of
extinction
4.3 –
Conservation
of biodiversity
IB Topics 4.3.1-4.3.5
Values of Biodiversity
 Products:

Timber/medicine
 Ecosystem
health/productivity
 Science
 Education
 Genetic diversity
 Recreation
&
ecotourism
 Aesthetic value
 Ethical reasons
Conservation Organizations
NGOs
 Not
run by, funded
by, or influenced
by any
country/governme
nt
 Ex: WWF,
Greenpeace
GOs
 Established
through
international
agreements
 Ex: UNEP, IUCN
Conservation Organizations
NGOs





Use of media
Speed of
response
Dimplomatic
constraints
Political
influence
Enforceability
GOs
Designing a Protected Area
 Large
vs Small
 Large
vs Many
 Close
vs Separate
 Clumped
 Corridors
 Round
 Buffer
vs Spread out
vs Not connected
vs Other shapes
zone vs No buffer
Protected Areas
 The
US has 7500+
protected areas
covering over 1.25
million square miles
Zoos & Conservation
 Zoos
bring
awareness to
conservation
 Zoos can help
breed and
reintroduce
species