CHAPTER 14 :

Conservation Biology = to preserve and conserve species, communities and ecosystems
Studies the causes of decline in species richness and methods to prevent declines

to prevent excessive rate of extinction to update the status of ecosystems and their services measures to be taken to sustain ecosystem functions

Environmental Stress
Organism Level
 Physiological changes
 Psychological changes
 Behavior changes
 Fewer or no offspring
 Genetic defects
 Birth defects
 Cancers
 Death
Population Level
 Change in population size
 Change in age structure
(old, young, and weak may die)
 Survival of strains genetically resistant to stress
 Loss of genetic diversity and adaptability
 Extinction
Community or Ecosystem
Disruption of energy flow through
 Disruption of energy flow
 Lower sp diversity
 Habitat loss & degradation
 Ecosystem collapse
 Less complex food webs
 Lower stability
Environmental Stresses defined at 3 levels : organism, population and
Ecosystem
© 2004 Brooks/Cole – Thomson Learning

the variety of species in the ecosystems

Genetic diversity in a vole population
Species diversity in a coastal redwood ecosystem
Three levels of biodiversity
Community and ecosystem diversity across the landscape of an entire region

Variation between distinct populations of the same species or varieties
Brought about by genetic recombination, gene and chromosomal mutation
The gene pool is shaped by Natural Selection
– variation
– reproductive fitness and
– mode of inheritance
– competition

The variety of species in an ecosystem or the biosphere
– Species diversity – variety (diversity) of species or species richness
Threatened species
Endangered species

Threatened
still abundant in natural range but declining and is likely to become endangered
Endangered
individuals are few and could become extinct over all or most of its range,
- moves from endangered to critically endangered

300972
Credit: © Michele Burgess/Visuals Unlimited
Silversword plant at Hawaii, an endangered species.

Credit: © Arthur Morris/Visuals Unlimited
Key Deer, Florida, an endangered species.
301423

Credit: © Ken Lucas/Visuals Unlimited
Museum specimen of the Passenger pigeon, North America that became extinct in 1914.
178223

Illegal Cambodian market with baby
Macaques, adult
Porcupine, and
Crocodile skulls.
Credit: © Robert Fournier/Visuals Unlimited

Credit: © Robert Fournier/Visuals Unlimited
Tiger bones in sesame oil for illegal sale in Myanmar market, folk medicine.
302744

Credit: © Robert Fournier/Visuals Unlimited
Snake skin, Sambar skull, and Elephant penis hanging in illegal market in Myanmar.
302743

Variety of places where life exists, where there is exchange of energy and nutrients
Each habitat is a home for multitude of species, and species are dependent on these habitats – food, mating, protection, etc.
When habitats are destroyed, species niche are destroyed, and species follow suit

Natural environment provides aesthetic, spiritual and educational needs for tribal people in Africa, Asia, Oceania and Americas
This relationship has allowed sustainable use of resources and has allowed for humans and other species to prosper together

Extinction is a natural phenomenon
The current rate of extinction due to ecosystem degradation by a single species –
Homo sapien , underlie the biodiversity crisis

Habitat Destruction and Fragmentation
Introduction of Non Native Species
Over-exploitation/Overuse of Natural Resources
Disruption of Food Chains
Climate Change
Pollution
Predator & Pest Control
Commercial Hunting & Poaching
Sale of Exotic Pets and Decorative Plants

Species Endemism and Hot Spots
Endemic – a species found naturally in only one geographic area and no where else
E.g
– Komodo dragon – Varanus komodoensis – only found on some islands in Indonesia
– The orang utan – Pongo pygmaeus – only found in Borneo and
Sumatra
Hotspots – area having concentration of endemic species – in SEA – Peninsular Malaysia, Indonesia,
Borneo, Philippines

Earth’s terrestrial biodiversity hot spots
Terrestrial biodiversity hot spots
Equator

Figure showing Major connections between Human
Activity and earths Biodiversity

Human Population
Size and resource use
Human Activities
Agriculture, industry, economic production and consumption, recreation
Direct Effects
Degradation and destruction of natural ecosystems
Changes in number and distribution of species
Alteration of natural chemical cycles and energy flows
Pollution of air, water, and soil
Anthropogenic activities affecting
Biodiversity
Climate change
Indirect Effects
Loss of biodiversity

The Species
Approach
Goal
Protect species from premature extinction
Goal
Protect populations of species in their natural habitats
The Ecosystem
Approach
Strategies
• Identify endangered species
• Protect their critical habitats
Strategy
Preserve sufficient areas of habitats in different biomes and aquatic systems
Goals strategies and tactics to reduce biodiversity losses
Tactics
• Legally protect endangered species
• Manage habitat
• Propagate endangered species in captivity e.g panda
• Reintroduce species into suitable habitats e. bettong sp.
Tactics
• Protect habitat areas through private purchase or government action (PA)
• Eliminate or reduce populations of alien species from PA
• Manage PA to sustain native species
• Restore degraded ecosystems

Local extinction – not found in local area but elsewhere still found
Ecological extinction – few members are left & no longer play ecological roles
Biological extinction – when species no longer found anywhere on earth

(a) Philippine eagle
(b) Chinese river dolphin
(c) Javan rhinoceros

Florida manatee
Northern spotted owl (threatened)
Gray wolf Florida panther Bannerman's turaco (Africa)
Devil's hole pupfish
Snow leopard
(Central Asia)
Symphonia
(Madagascar)
Black-footed ferret
Utah prairie dog
(threatened)
Ghost bat
(Australia)
California condor
Black lace cactus
Black rhinoceros
(Africa)
Oahu tree snail

Grizzly bear
(threatened)
Kirtland's warbler
White top pitcher plant
Arabian oryx
(Middle East)
African elephant
(Africa)
Mojave desert tortoise
(threatened)
Swallowtail butterfly
Humpback chub
Golden lion tamarin
(Brazil)
Siberian tiger
(Siberia)

West Virginia spring salamander
Giant panda
(China)
Whooping crane
Knowlton cactus
Blue whale
Mountain gorilla
(Africa)
Pine barrens tree frog
(male)
Swamp pink
Hawksbill sea turtle
El Segundo blue butterfly

(*) Ecological extinction – few members are left & no longer play ecological roles
(*) Biological extinction – when species no longer found anywhere on earth

Characteristic
Low reproductive rate
(K-strategist)
Specialized niche
Narrow distribution
Feeds at high trophic level
Fixed migratory patterns
Rare
Commercially valuable
Large territories
Examples
Blue whale, giant panda, rhinoceros
Blue whale, giant panda,
Everglades kite
Many island species, elephant seal, desert pupfish
Bengal tiger, bald eagle, grizzly bear
Blue whale, whooping crane, sea turtles
Many island species,
African violet, some orchids
Snow leopard, tiger, elephant, rhinoceros, rare plants and birds
California condor, grizzly bear, Florida panther
Everglades kite
African violet
California condor

How does a biologist know if a particular species is vulnerable to extinction?
1.
2.
3.
4.
Observing changes in an organisms population size and habitat availability
Species whose populations are shrinking rapidly
Species whose habitats are being destroyed
Species that are endemic to small area and rare

90% deforestation/loss of habitat causes extinction of 50% of species
Destruction of last 10% causes extinction of all species especially if the species cannot move out of the area

1.
PVA – Population Viability Analysis
2.
MVP – Minimum Viable Population
3.
MDA – Minimum Dynamic Area

to predict if population will persist based on: i.
Current & predicted habitat condition and resource needs ii.
Genetic variability iii.
Interactions with other species iv. Reproductive rates and population dynamic

Minimum number of individuals necessary to ensure survival of a population

Minimum area of suitable habitat needed to maintain the MVP

Why should we care about biodiversity – what’s so bad about losing it – what’s it value?
1.
Direct Economic Value (consumable)
- nature product that are consumed directly – consumptive use value that do not pass through markets
2.
Indirect Economic Value (ecological services)
3.
(Option value) Natures products that are commercially harvested – productive use value – biological resources
4.
Ethical & Aesthetic Value

Necessity – genetic codes are linked to medicines, food production, jobs and survival
Important to Economy
Essential for Food Security

Safeguards Human Health
Recreation & Tourism
Global Concern - Losses to biodiversity can threaten national security – conflicts over water, land, global warming
Species Extinction
Aesthetic Beauty

Two biggest causes
1. Habitat loss, fragmentation & degradation
2. Introduction of nonnative species

Figure 22-13 (4)
Page 573
Former range
Range today
(34,000 –54,000 left)
Asian or Indian Elephant

Characteristics of
Successful
Invader Species
• High reproductive rate, short generation time
(r-selected species)
• Pioneer species
• Long lived
• High dispersal rate
• Release growthinhibiting chemicals into soil
•
Generalists
• High genetic variability
Characteristics of
Ecosystems Vulnerable to Invader Species
• Similar climate to habitat of invader
• Absence of predators on invading species
• Early successional species
• Low diversity of native species
• Absence of fire
• Disturbed by human activities

An artificial corridor