content - forests Flashcards
How biotic and abiotic characteristics are interdependent in a tropical rainforest
- Climate
- Soil
- Water
- Plants
- Animals
- Humans
how plants are adapted in TRF - 4
- stratified layers
- buttress roots = stables very tall trees
- drip tips = downward sloping leaves = surface water runs off quickly = otherwise moss + algae would grow on it = blocking the light
- tall trees = called emergents = 50+ metres tall = compete for light
how animals are adapted to TRF
- camouflage = avoid predators eg. Chameleons can change their skin colour to match surroundings
- better grip + balance = powerful legs adapted to be able to grip branches
Why does the tropical rainforests have a very high rate of nutrient cycling w
- fast decomposition
- leaching
why does the TRF have high levels of biodiversity
- conditions for plant growth so good = allowing ecosystem to support thousands of diff species
- TRFs are ancient ecosystems = they have developed over 100 / 1000s of years = many species have adapted + evolved to meet the needs of the rainforests
How biotic and abiotic characteristics are interdependent in taiga
- -Climate - Soil - Water - Plants - Animals - Human
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how are plants adapted to the taiga
- Cone shaped needles leaves // pine needles = small SA = less water loss // dark green = more photosynthesis = more light absorption // very little sap = do not freeze easily + can continue to operate in cold conditions
- grow close together = grain protection from the wind
- conical shape = downward facing branches = so the snow doesn’t accumulate and break the branch = it slides off
how are animals adapted to the taiga
- Migratory animals = migrate south to warmer conditions 300 vs 30
- thick fur coats for insulation
- smaller ears / short tails = avoid frostbite
- ability to hibernate = bears build up fat reserves in the summer = hibernate in the den through much of the winter = enter a sleep - like state
- winter camouflage = white coat = away from predators
Why does the taiga have lower productivity
- taiga plant growth limited to the short summer = biomass small = productivity is small
- decomposition of the litter layer is small and even stops during the winter deep freeze = soil as low nutrients level
- only a few specialist plant species can survive the taiga climate - biodiversity is low overall
why does the TRF have higher productivity
- long growing season
- high temp + rainfall
why does the taiga have less active nutrient cycling and much lower levels of biodiversity
- short growing season
- only specialised plants can = pine needles = acidic soils
- very cold
- low levels of decomposition
causes of deforestation in TRF
- commercial hardwood logging
- subsistence and commercial agriculture
- local demand for fuel wood
how demand for biofuels, mineral resources and electricity (HEP) contribute to deforestation
- clear land
- creation of HEP stations in the Amazon Basin has resulted in large areas of forest being flooded to create the reservoirs and dams. The flooding of the Balbina dam in Brazil resulted in the loss of 920 square miles of tropical rainforest.
Why climate change is an indirect threat to the health of tropical rainforests;
- ecosystem stress = species not adapted to deal with heatwaves = stress
- drought = cause a northward shift in the atmospheric system that brings wet weather to TRF = do not bring as much rain to the rainforests = hotter + drier = higher risk of forest fires
taiga direct threats
- logging for softwood
- = removes trees = no trees = mo pine needles = lower soil nutrients =
- logging technique used is clear cutting = trees cut down + transported to sawmills for pulp and paper production
taiga indirect threats
from the exploitation of;
- minerals
- fossil fuels
- HEP potential.
side effects
- oil spills = Russias oil industry spills 5 million barrels of oil a year = very damaging to taiga because drainage is poor = oil doesn’t get washed away = as decomposition is very slow = oil remains in ecosystem for a very long time
