A4.2: Conservation and Biodiversity

Biodiversity

Variety or multiformity, being different in character and quality

Types of Biodiversity (3)

ecosystem, species, genetic

Ecosystem Diversity

Combinations of species in communities due to varied environments

Species Diversity

Different species on cladograms

Genetic Diversity

Differences in gene pool of each species

Previous 5 Extinctions & Potential 6th

First 4 due to volcanic activity/climate change, most recent occurred due to asteroid collision (66 M yrs ago)

6th will be due to human activity

Current Biodiversity

About 2M named species (10M undiscovered), biodiversity has been increasing and more species now than anytime in past.

Extinction

A natural process, typically balanced by evolution so doesn't decrease biodiversity.

But now destruction/extinction is happening faster than evolution (bad)

Anthropogenic Extinction

extinction caused by humans

Causes of Extinction (5)

Overharvesting, Habitat Destruction, Invasive Species, Pollution, Global Climate Change

Overharvesting

hunting animals, plant harvesting, fishing (too much)

Habitat Destruction

For agriculture, livestock, & towns/cities

Invasive Species

Alien species can drive native species into extinction via predation, competition, disease spread, or infertile hybrids

Pollution

Chemicals used and discarded in ENV, fossil fuels, mining, oil, pharmaceuticals

Global Climate Change

Rapid changes in temp, rainfall, snow cover

Species that can migrate will, others will go extinct

Extinction Examples (2)

Giant Moas & Mount Glorious Torrent Frogs

Giant Moas

Large flightless birds native to New Zealand, extinct 200yrs after Polynesians arrived in 13th century

Mount Glorious Torrent Frogs

Lived in northeastern Australia rainforests, extinct by 1980 bc of deforestation, altered water flow, turbidity (cloudiness) in water, and predation of alien feral pigs and feces contamination in waterE

Ecosystem

Community of organisms that live and interact in a specific environment, made of interdependent components

Ecosystem Loss

Caused by when key parts are impacted (keystone species), entire ecosystem can collapse and be lost

Causes of Ecosystem Loss (6)

Change in land-use, urbanization, dams and water extraction for irrigation, overexploitation of natural resources, eutrophication, and climate change

Change in Land-Use

For agriculture expansion, forests, grasslands, and wetlands for farming

Urbanization

Homes, offices, factories, roads, railways

Dams and water extraction for irrigation

Water removed from rivers for agricultural and domestic use, constrained by dams from overflowing (no more marshlands)

Overexploitation of Natural Resources

Gathering of wood, hunting, fishing, disturbance of keystone species threatens ecosystems.

Eutrophication

leeching of fertilizers into rivers and lakes causing agal bloom, leads to depleted dissolved O2, harming other species

Climate Change

Ecosystems adapted to specific climates, change hurts them

Loss of Ecosystem Examples

Mixed Dipterocarp Forest in Southeast Asia, Aral Sea

Mixed Dipterocarp Forest

family of diverse topical rainforest trees targeted for timber. disturbance causes peat (prelude to coal, soil w/ partially decomposed organic matter) to decompose, releasing CO2, ultimately leading to global warming.

Aral Sea

Was 4th largest lake in Kazakhstan/Uzbekistan, fed by river but only water loss through evaporation. Rivers diverted for irrigation, salinity increased from 1% to 22%, all fish species and many invertebrates went extinct

Biodiversity Crisis

unprecedented loss of ecosystems and species

IPBES

Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Sources, gives evidence to support biodiversity crisis

Where does biodiversity crisis data come from? (8)

-population size

-species range

-species diversity

-richness & evenness of biodiversity

-ecosystem area

-extent of ecosystem degradation

-number of threatened species

-genetic diversity

Cause of Biodiversity Crisis

ecosystem collapse normal in history, danger is pace and intensity of ecosystem collapse currently

Human Impact in Biodiversity Crisis (5)

We are the main cause, main issue is overpopulation, which leads to

-hunting and over-exploitation

-urbanization

-deforestation and land-clearance for agriculture

-pollution

-spread of invasive species due to global transport

Biodiversity Conservation Approaches

In Situ and Ex Situ

In Situ Conservation

conservation of species in natural habitat, leaving areas of wilderness pristine via legislation/land purchase for natural parks

Advantages of In Situ

animals already adapted to environment, continue interactions so niche preserved, behavioral patterns continue normally

and cheap!

Management of Nature Reserves (5)

-removal of alien species

-reintroduction of extinct species

-prevention of poaching

-supplementary feeding

-controlling human access

Rewilding

return of degraded ecosystems to natural state so balance can be maintained by natural processes.

Ex Situ Conservation

conservation in zoos and botanic gardens, organisms removed from wild, bred in captivity, and released