mbb biodiversity

7/30/2019 MBB Biodiversity

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BIODIVERSITY

THREATSBy Inna Mercado


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Biodiversity loss


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WHAT IS EXTINCTION?


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EXTINCTION

The end of an organism or of a group of organisms

The death of the last individual of the speciesdefines the moment of extinction


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Natural Causes

It is believed that 99.9% of allthe species that ever lived areextinct.

Typically, a species becomeextinct within 10 million yearsof its first existence


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BAIJI DOLPHIN (2006)


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Hawaiian Bird (2002)


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Habitat Destruction


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HABITAT DESTRUCTION

The process in which a natural habitat is consideredunable to sustain the species present

Primary cause of extinction worldwide

Currently, the most threatened habitats orecosystems are the ones found in freshwater


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In 1986, 82% of endangered bird specieswere significantly threatened due to

habitat loss.


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Tropical rainforests are being destroyed

at the rate of 0.8-2.0% per year


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Human Activities AffectingHabitat Loss

ACTIVITY HABITATSAFFECTED

IMPACT

SHORELINEARMOURING

Intertidal and subtidalshorelines

Increased exposure towave energy; fewerspecies can survive

FISHING Subtidal and deepwater marine areas

- Physical destructionof bottom-dwellingplants/animals- By-catch

DREDGING Subtidal, intertidal andfreshwater habitats

- Physical destructionof bottom-dwellingplants/animals- Fewer plants cangrow in reduced light;- fish gills become

clogged with sediment


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Human Activities Affecting HabitatLoss

ACTIVITY HABITATSAFFECTED

IMPACT

DIKING AND IN-

FILLING

Estuaries, shorelines,

wetlands

- Productive intertidal

and wetland habitat isdestroyed

LOGGING ANDVEGETATIONREMOVAL

Marine, upland,freshwater habitats

- Destroys structure ofhabitat-machinery disturbs

soil- Can create erosion

LOG BOOMING Lakes, shelteredmarine habitats

- Destruction ofbottom-dwelling

plants/animals-Decomposition of


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Human Activities AffectingHabitat Loss

ACTIVITY HABITATS AFFECTED IMPACT

AGRICULTURE Upland, marine,freshwater habitats

- Replacement of diversehabitats with single-species crops

- Possible runoff oflivestock wastes,pesticides, fertilizers,into freshwater andmarine environments

INDUSTRIAL ANDAUTOMOBILEPOLLUTION

All habitats - Many substances aredirectly toxic toplants/animals; othershave long-termcumulative effects onhealth


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Introduced and Invasive

Species


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Introduced and InvasiveSpecies

- A species living outside its native range though humanactivity either accidentally or intentionally.

- May be beneficial or not

Invasive Species

Introduced Species

- Introduced species that lead to adverseaffects to habitats they have invaded


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Invasive Species

Often upsets the balance within ecosystems

May cause disruptions by dominating a region from

loss of control

Reproduce rapidly due to being free from predationand competition

Introduced species become invasive if itoutcompetes native species for resources


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Common Invasive Traits

Fast growth

Rapid Reproduction

High dispersal ability

Phenotypic plasticity

Tolerance of a wide range of environmental conditions

Ability to live off of a wide range of food types Association with humans

Prior successful invasions


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Ecological Facilitation

Occurs when a species alters its environment withthe use of chemicals or manipulating abiotic factors

Allows invasive species to proliferate while makingtheir environment less favorable to competitors


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BROWN TREE SNAKE


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Ecological Facilitation

Centaura Bromus Tectorum


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Overexploitation


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Overexploitation

Occurs when a resource is consumed at anunsustainable rate, given their natural rates ofmortality and capacities for reproduction

May be in the form of overhunting, excessivelogging and illegal wildlife trade

O h i /Wildlif


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Over-hunting/WildlifeSmuggling

Highly profitable

Done usually for economic

reasons such as for foodand clothing

Can cause cascade effects

Hy ri ization Genetic


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Hy ri ization, GeneticErosion/Pollution, and Food

Security Imply a lack of genetic diversity

Formerly used gene pools of various indigenousbreeds have collapsed due to geneticpollution/erosion


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Genetic Erosion

A process wherein an endangered species with alimited gene pool diminishes even before it gets thechance to meet and breed with others in theirpopulation

May also be caused by habitat fragmentation


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Climate Change


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Climate Change


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Coral Bleaching

An increase in thepreferred temperature maycause discoloration

Causes death among corals

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