habitats Flashcards
(35 cards)
What abiotic conditions are critical to coral survival and why? (5)
1) High light levels needed for photosynthesis
2) Temperature: Temperature must be warm and constant, in the range of 25-29C
3) Low Turbidity: Seawater must have very low turbidity as turbid water reduces light penetration so photosynthesis would be reduced and to prevent sediment from sticking to polyps
5) Salinity: If the salinity of the water changed outside the narrow range of the corls, the cells would be killed by osmosis with water flowing into or out of the cells.
What are the importances of tropical coral reefs and explain? (5)
1) Fisheries: including fish, crustaceans such as lobsters and molluscs such as coral.
2) Medicinal discoveries: corals produce toxic chemicals which may be useful as medicines when used in carefully controlled amounts.
3) Climate Control: growing coral reefs are an important carbon sink, helping to resist climate change.
4) Erosion protection: Coral reefs absorb the energy of waves that would otherwise have eroded or washed away nearby islands.
5) Tourism: Coastal areas and islands with coral reefs are popular tourist populations for ecotourism activities such as scuba diving and snorkeling, as well as relaxation in pleasant surroundings.
What are the threats to tropical coral reefs? (7)
1) Physical damage: Hard objects can kill polyps as they are pushed against the hard limestone beneath the living cells. Litter such as bottles, lost fishing gear, boat anchors and careless drivers can all damage reefs
2) Sedimentation: Turbid waters carried by rivers or sediments disturbed by coral developments can cover and kill corals.
3) Pollution: Pollutants such as oil spills can cover coral reefs which is toxic to corals. Nutrients such as nitrates and phosphates from agricultural runoff can stimulate the growth of algae which covers the corals.
4) Introduced Species: introduced from ballast water discharged from ships, escaped fish from fish farms and accidental and international releases from aquaria.
5) Fishing: If there is an excessive catch-rate, fish populations will decrease and affect other inter-dependent species. Over-fishing of the Giant Triton allowed Crown of Thorns starfish populations to rise which are harmful to coral reefs
6) Climate change
What are the conservation efforts for tropical coral reefs (5)?
1) Marine protected areas: fixed mooring bays to reduce use of anchors, divers/swimmers told not to touch the corals, controlling of fishing, sustainable development of ecotourism.
2) Control of fishing: Control methods include: length of fishing seasons restricted, No take zones where fishing is banned, restrictions of damaging fishing equipment.
3) Control of tourism: Recreational activities may be restricted to minimise the damage the damage that may be caused (eg banning of spear fishing and turtle nesting beaches may be protected to reduce disturbance).
4) Establishment of protected areas eg The Great barrier reef
What are the ecological features of deep water coral reefs:
- cold and dark so coral growth is slow
- no light for photosynthesis so regrowth after damage is slow
What are the importances of deep water coral reefs?
1) Research- potential medical benefits eg chemicals from sponges
2) proxy data
3) Fisheries
What are the threats to deep water coral reefs (3)?
1) Deep water trawling
2) The expansion of oil and gas exploration in deep water is a future threat,
3) Increased releases of carbon dioxide are gradually causing the acidification of oceans. This may threaten the survival of deep water corals.
Describe how named methods of conservation protect
Antarctica. [5 marks]
- limited numbers of tourists ashore/ areas visited/ boats to prevent
disturbance to wildlife / erosion - shoe covers/ sterilisation/ protective clothing/ no dogs to reduce
introduction of disease/ non-native species - visitors with guides only to restrict disturbance/ raise awareness
- removal of waste to prevent contamination/ pollution
- no mining/ resource exploitation to prevent habitat destruction/
pollution - no military use/ weapons testing to prevent damage to biotic and
abiotic environment - restrictions on fishing/ monitoring of fish populations to reduce overexploitation/ food chain impacts
- named methods to control greenhouse gas concentrations to
reduce global climate change/ named impact - control of ODS/CFCs to reduce Antarctic ozone depletion/ reduce
UV impacts to phytoplankton/ wildlife - freedom of scientific inv
- Antarctic Treaty (1959)/ Madrid Protocol (1998/1991)
What are the conditions in the Antarctic treaty?
1) Antarctica should only be used for peaceful means
2) Antarctica can be used for scientific research but all research has the right to be shared and cooperated on
3) All stations and operations can be inspected at any time
4) Antarctica is not any country’s territory
5) Nuclear activity is banned
What are the criticisms of the Antarctic treaty?
1) Not mandatory meaning countries can choose not to sign it
2) Inspections do not occur often
3) All decisions must be unanimous
Describe two climatic features of temperate broadleaf forests.
[2 marks]
- regular/ moderate precipitation/ wetter winters/ drier summers
- no major temperature extremes/ mild summers (not very hot)/ mild
winters (not very cold) - distinct/ four seasons
- moderate humidity
Explain how one named biotic factor affects the soil characteristics in a temperate broadleaf forest. [2 marks]
- leaf litter/ faeces
- increases nutrient content/ DOM
- worm activity/ burrowing/ foraging and shelter building
- increases aeration/ infiltration/ drainage
- root action
- increases aeration in soil
- detritivores/ decomposers/ bacteria
- increases nutrients
- tree roots/ OM
- Increases aggregation of soil
State two other abiotic factors that mangrove trees are adapted to.
[2 marks]
- salt water
- partly covered by water/tidal zones/shallow
water - low oxygen (in sediment).
- strong winds
Explain two ways that the conservation of mangroves can benefit coral reef ecosystems.[2 marks]
- trap sediment reducing turbidity allowing light for
coral photosynthesis/preventing smothering - nursery grounds for fish migrate to populate
coral reefs - sequester carbon regulating temperatures with
range of tolerance (preventing coral bleaching) - nutrient uptake reducing eutrophication.
Compare the threats to tropical coral reefs with the threats to deep water coral reefs (9 marks)
Similar threats to both coral reef ecosystems
* destructive fishing methods: damage the seabed destroying
feeding/breeding grounds
* demersal trawling scrapes away seabed
* demersal longlining snags corals
* shellfish traps damage on impact
* ghost fishing from discarded fishing gear kills species
* overfishing removes species above the MSY resulting in
population decline
* ocean temperature increase: beyond range of
tolerance/breakdown in interspecies relationships/causing
reduced oxygen
* ocean acidification: reduction in pH and calcium carbonate
saturation reduces growth rate
Deep-water coral reefs only
* hydrocarbon exploration/production causes physical impact
from oil platforms
* pipelines causes impacts from mud discharges from rock drilling
* potential threat from oil spilled from mechanical fault at site of
extraction
* telecommunication/electricity cables
* burial in the seabed disturbs sediment into water smothering
coral
* potential treat from future mineral exploration with the increase
in AUVs/ROVs eg metals from deep sea nodules
* changes in ocean currents that deliver nutrients
Tropical coral reefs only
* tourism: damage from boat anchors/ touching/ disturbance/
souvenir collection
* pollution from surface run off: sewage/fertiliser causing
eutrophication
* increase turbidity/sedimentation from soil erosion due to
development/ agriculture/ destruction of mangroves
* introduced species
* coral bleaching
Suggest two reasons why the natural recovery of a deep-water coral reef takes much longer than the natural recovery of a tropical coral reef (4 marks)
1) Less light available for photosynthesis- reduced growth rate
2) Lower temperatures- lower energy input
Give one reason why tropical coral reefs are more likely to resist change than deep-water coral reefs (1 mark)
More interspecies relationships/stable food webs
Explain one physical feature of oceanic islands that affects which species colonise the habitat (2 marks)
Oceanic islands are isolated from any major land masses which makes it difficult for many species such as terrestrial mammals to colonise
What are the threats to Temperate broadleaf woodland?
- deforestation due to agriculture, urban expansion etc
- management change eg removal of old dying trees and replacement with single-age monocultures.
Describe how nutrient availability affects productivity in oceans around Antarctica compared to tropical oceans (6 marks)
- Antarctica’s cold oceans very nutrient rich all year round
- due to storms and upwellings of deep, nutrient rich water
- has very high productivity
- Tropical oceans have very separate layers of water which do not show vertical mixing
- This prevents nutrient rich water from rising to the surface which limits productivity
- low productivity
- Antarctic waters have consistent high levels of nutrients whereas tropical waters have consistent low levels of nutrients.
Importance of temperate broadleaf forest
- climate control
- recreation
- soil erosion control
- resources eg timber and charcoal
- high biodiversity
Conservation management of temperate broadleaf woodland
- designated protected areas- many ancient woodlands are SSSIs or SACs
- conservation management eg coppicing, pollarding
climactic features of tropical rainforests
- warm/hot
- high rainfall
- high light levels
- low seasonal variations- provides food all year round
- abiotic conditions allow for rapid plant growth and food production
importance of tropical rainforests
1) high biodiversity
2) resources eg new medicines, genetic material
3) carbon sequestration
4) hydrological cycle
5) soil erosion control
