A4.2 conservation of biodiversity

Question 1

biodiversity

Answer 1

biodiversity is the variety of life in all its forms, levels and combinations found in an area

3 different levels:
- ecosystem
- species
- genetic

Question 2

ecosystem diversity

Answer 2

considers diversity from the largest overall viewpoint

e.g in the great barrier reef each individual reef has its own ecosystem and high biodiversity, therefore the total ecosystem biodiversity in the region is very high.

high level of diversity of ecosystems provides stability in the environment and generates a great deal of species and genetic diversity

Question 3

species diversity

Answer 3

individual ecosystems have varying degrees of species diversity, the number of different species in a community

healthy ecosystem have both high species richness and evenness

Question 4

genetic diversity

Answer 4

variety in the gene pool of each species

populations with greater genetic diversity are more stable and can better withstand environmental pressures such as disease and extreme weather events

Question 5

biodiversity over time

Answer 5

millions of species have been discovered and many more are being discovered everyday.

fossil records suggest that there are more species alive today than at any other geological time period

Question 6

causes of anthropogenic species extinction

Answer 6

1. the north island giant moa
2. the carribean monk seal
3. the dodo brid

Question 7

the norh island giant moa (case study 1)

Answer 7

an extinct species that lived in new zealand up until as recently as 1300 CE

• extremely large herbivorous birds
• swallowed and retained stones in their gizzards in order to grind the plants in their diets for more nutrients
• no wings
• females larger than males
• covered in long feathers

hunted to extinction within 100 years of arrival of polynesian people on the island

(anthropogenic extinction has been happening for centuries)

Question 8

the carribean monk seal (case study 2)

Answer 8

declared extinct in 2008

• docile marine mammals
• lived around the waters of the gulf of mexico and caribbean islands

european colonists killed this seal for its oil to use for lamps and food

some of the last caribbean monk seals were killed to provide scientific specimens

Question 9

the dodo bird (Case study 3)

Answer 9

The last dodo was killed in 1681, and the species was lost forever to extinction. The dodo was endemic to the island of Mauritius.

The birds had no natural predators

• decimated by sailors and other people as an easy source of fresh meat
• humans settled on the island bringing new predators such as pigs and monkeys that ate the eggs and competed with the dodo birds for food

** over-harvesting, habitat loss and newly introduced animal competition lead to the extinction of the dodo birds**

Question 10

causes of ecosystem loss

Answer 10

1. mixed diptercarp forests in Southeast Asia
2. tallgrass prairie

Question 11

mixed diptercarp forests in Southeast Asia (case study 1)

Answer 11

family of hardwood, tropical trees compromising about 500 species

• uniquely biologically complex.
• Deforestation rates in SE Asia are some of the highest globally

clear-cutting, the forested land is completely stripped of its trees=total loss of local ecosystem, it is the cheapest option

Question 12

tallgrass prairie (case study 2)

Answer 12

• in Nebraska, 98 percent of the tallgrass prairie and 35 percent of wetlands have been lost, primarily due to conversion to cropland

Farming, Buildings and Roads, Fire Suppression (allows invasive species such as eastern red cedar to take over), Overgrazing

Question 13

evidence for biodiversity crisis

Answer 13

1. IPBES published a report that provides significant evidence from a wide range of habitats on the current global extinction risk in different species
2. IUCN red list is a continuously updated list of the world’s threatened species

evidence can be gathered directly by carrying out reliable surveys, they must be repeated:
- numbers in populations of the species
- genetic diversity
- range of the species
- species diversity
- richness and evenness
- area occupied

Question 14

anthropogenic causes of the sixth mass extinction

Answer 14

human population growth is the overarching cause but more specifically:
- habitat destruction, clearance of land for agriculture

• deforestation
• introduction of invasive species
• pollution (air=smog, water=eutrophication)
• spread of pests and diseases
• climate change
• agriculture
• urbanization
• hunting overexploitation of natural resources

Question 15

conservation of biodiversity

Answer 15

no single approach by itself is sufficient, different species require different measures.

in situ conservation: managing natural areas

ex situ conservation: managing one or more species outside their natural area

Question 16

in-situ conservations

Answer 16

• national parks: preserve wildlife in that area, prevent ecosystems from being lost through anthropogenic activity
• nature reserves: smaller than national parks, protect ecosystems from urbanization and uncontrolled use
• rewilding of areas damaged by human intervention: promotes forest and aquatic ecosystem regeneration (removal of dams and roads) allowing previously fled species to return, thereby increasing biodiversity
• reclamation of degraded landscapes: rebuild and replant as much of an ecosystem as possible that was damaged through anthropogenic activities e.g clear cutting of forests

Question 17

ex situ conservation

Answer 17

• zoos: animal husbandry facilities to promote the continuation of species that are threatened and endangered, artificial insemination to restore populations of captive animals
• botanic gardens: provide a living store of plant material to promote biodiversity, exchange seeds or pollen to preserve rare, threatened or endangered species.
• seed banks: stores seeds of species safely to repopulated species if necessary
• animal tissue banks:
  1. germplasm (sperm, eggs, embryos) stored cryogenically to be able to repopulate the species if necessary
  2. somatic tissue, non-reproductive tissue samples for DNA research and cloning

Question 18

ecosystems

Answer 18

A community of living organisms interacting with each other and with the non-living environment within a defined area. These interactions include energy flow and nutrient cycling.

Question 19

the EDGE of existence programme

Answer 19

Evolutionarily Distinct and Globally Endangered species for conservation prioritization.

species are selected for priority status in conservation programmes and evaluated using molecular technology to give them an EDGE score