P1B Living world Flashcards
1
Q
define ecosystem
A
a community of plants/animals (biotic factors) that interact with each other and their physical environment (abiotic factors)
2
Q
describe the location of rainforest biomes
A
on/around the equator, between the tropics, across the globe, largest Amazon in south america
3
Q
describe the conditions of rainforest biomes
A
- hot/wet/humid climate all year
- greatest biodiversity+productivity due to greatest biomass
- high rainfall all year
- due to Hadley cell circulation forming warm/moist air around the equator
4
Q
describe the location of desert biomes
A
near tropics 30 degrees N+S of equator, across the globe, largest is Sahara in north africa
5
Q
describe the conditions of desert biomes
A
- hot/dry climate in day, cold at night
- thin/sandy soil
- very low rainfall
- lack of plants+species, few adapted to drought
6
Q
describe food webs
A
a network of food chains (plants+animals) relying on each other for food
7
Q
describe the hierarchy of a food chain (4)
A
producer (gets energy from sun by photosynthesis)
-> decomposer/primary consumer
-> secondary consumer
-> tertiary consumer/apex predator
8
Q
describe the structure of a rainforest (5)
A
- emergents: leaves have drip tips to shed heavy rain
- upper canopy: tall/thin trunks to reach sunlight, woody vines (lianas) climb to reach sunlight
- lower canopy/ understory: dense vegetation
- shrub layer/ forest floor: buttress roots support trees, litter layer of decaying vegetation
- shallow soil
9
Q
describe the condition of rainforest soil
A
- low in nutrients, infertile
- due to leached soil by heavy rainfall + abundance of vegetation (high competition)
- deforestation further leaches the soil due to less interception/ surface storage
10
Q
state rainforest plant adaptations (5)
A
- emergents have no branches - conserves energy needed to grow upwards for sunlight
- buttress roots - wide+triangular to stabilise tall/thin trees
- tree leaves - drip tips drain excess water during heavy rainfall, large surface area to absorb maximum amount of light for photosynthesis, waxy upper layer reduces water absorption
- pitcher plants - traps insects in sticky water inside to digest nutrients, source of food as leached soil lacks nutrients
- epiphytes - plants that grow on surface of another plant + gets nutrients from air+rain, don’t use much energy to grow upwards, benefit from lots of sunlight
11
Q
state rainforest animal adaptations (5)
A
- tail - assists with climbing+ balance (spider monkey)
- large eyes - help vision in dense/dark lower canopy (tarsiers)
- strong/long claws - help grip branches (toucan)
- long/strong limbs - assist with climbing (spider monkey)
- camouflage - hiding from predators or sneak up on prey (frogs)
12
Q
state the causes of deforestation (7)
A
- LOGGING: timber for homes/furniture or pulp for paper, either selective logging (cutting most valuable/minimum required amount) or clear-cutting/felling
- MINERAL EXTRACTION: forests cleared for open-cast mines, minerals found underneath Amazon rainforest eg. iron/ gold/ bauxite
- (HEP) ENERGY DEVELOPMENT large areas of forest flooded for dams/reservoirs, displaces people+animals, dams have a short life as become blocked with soil washed by heavy rain, eg. Jirau dam on Madeira river Brazil
- COMMERCIAL CATTLE FARMING: causes 80% deforestation + responsible for 340million tonnes carbon release, land has a short life as pasture quality declines quickly so more land is cleared
- COMMERCIAL CROP FARMING: forest cleared for palm oil/ soy plantations, due to high demand for resources, soil won’t sustain crops for long so more land cleared, eg. sugar cane used for biofuel / palm oil farmed in Indonesia
- ROAD BUILDING: built to bring in equipment+ bring products out, opens up dense parts of forests for development, many roads unusable during wettest parts of the yr unless paved, eg. Trans-Amazonian Highway
- SETTLEMENT/ POPULATION GROWTH: housing for forest workers, families need homes+ services+ jobs, eg. Parauapebas Brazil- iron ore mining town
13
Q
state local impacts of deforestation (5)
A
- DECLINE OF INDIGENOUS TRIBES: forced out of forest by road building/ logging/ plantations/ farms/ opening of mines, struggle to adjust from traditional living to modern towns, loss of forest knowledge of medicinal species
- SOIL EROSION: exposed topsoil removed by heavy rainfall, soil loses fertility so plants struggle to grow, so pastures/plantations abandoned due to low fertility so more areas cleared
- RIVER POLLUTION: mercury used in gold mining pollutes rivers, poisons fish habitats+ human drinking water in nearby towns, soil also pollutes rivers when washed away
- LOCAL CLIMATE CHANGE: disrupts water cycle (less transpiration as trees removed), lack of moisture so drier climate, water isn’t being recycled so hotter climate, bad conditions for agriculture
- CONFLICT: between indigenous people+ loggers, between developers+ conservationists
14
Q
state global impacts of deforestation (2)
A
- GLOBAL WARMING: less trees absorbing CO2, carbon released when wood burned, contributes to greenhouse effect+ climate change, responsible for 20% of global warming emissions
- LOSS OF BIODIVERSITY: species endangered or extinct, loss of medicines/cures to diseases
15
Q
state positive impacts of deforestation (4)
A
- EMPLOYMENT OPPORTUNITIES: felling/ mining/ farming/ road building
- BUILDING MATERIALS: timber
- FOOD: native food crops eg. fruit/nuts
- FARMLAND: crops/cattle
