Deserts & Rainforests Flashcards
national park
An area of rural land that is protected by government
nutrient cycle
Roots take up nutrients rapidly; nutrients make trees grow; dead leaves fall off trees; worms & bacteria break down dead leaves; deep soil is poor because nutrients can’t get to it.
adaptations of heliconia
Lots of sunlight needed so grow rapidly (4m per year) to find sunny areas; leaves in different positions have different absorption potential of sunlight for photosynthesis - can adapt if canopy above changes.
adaptations of a mandrill
Pads of thick skin - weight bearing surface as they sit; rotating shoulders - easy to grab branches in difficult directions; cheek pouches - hold lots of food to consume later.
average rainfall in Amazon Rainforest
6-10 feet - 1.8-3m
size of Amazon Rainforest
6.7 million square km
how many people live in the Amazon Rainforest
47 million, with over 2 million indigenous people
opportunities of living in the Amazon Rainforest
Water availability, clean air, food, building materials, income generation.
how does altitude of rainforests contribute to their high temp
Layers of atmosphere closest to Earth’s surface (low altitude) are warmer; rainforests are low altitude.
why is the rainfall always so high in rainforests?
Low pressure systems; higher energy from sun - rising air & evaporation; as warm, wet air rises it cools and condenses, forming clouds; high levels of precipitation.
definition of ecosystem
A biological community of interacting organisms & their physical environment.
definition of climate
Average conditions of atmosphere in one place over a long period of time.
temperature in deserts
Extremely high (especially in summer, lower in winter); may reach 30-34°C in summer; extreme day-night variation (diurnal).
why is there a varying temp in deserts during the year
Angle of sun changes (higher angle April-October & sun is directly overhead); sun-rays less concentrated September-March (Northern hemisphere).
rainfall in the desert
Low annual precipitation; unreliable; usually from 100-200mm per year.
what are desert soils like?
Sandy, rocky; 1m deep; little organic material due to lack of vegetation; high salt content.
how have cacti adapted to the desert?
Large, fleshy stems to store water; spikes to deter consumers; spines not leaves to reduce water loss by transpiration; thick, waxy skin to retain water; shallow, widespread roots to collect water.
location of Thar Desert
Area of high pressure; 27 degrees North of equator; in rain shadow of Aravalli mountains; inland, so no cool ocean currents.
climate of the Thar Desert
Extremely hot - average day temp 46°C, 5-10°C in winter; 100-500mm rainfall per year (average 150mm per year); 90% total rainfall is season of southwest monsoon (July-September).
why do people live in the Thar Desert?
Mining - for limestone & marble, used in construction; tourism - 120 animal species, multiplier effect = development opportunities; energy generation - mainly solar panels & wind energy, West Indian Wind Power project has 242 turbines, each with 800KW capacity.
development challenges of the Thar Desert
Extreme temps - can be over 50°C - hard to work outside; water supply - 150mm rain per year, growing crops is hard; inaccessibility - 200,000 square km, extreme environmental conditions & poor infrastructure.
sustainable
Meeting the needs of the present without compromising the ability of future generations to meet their needs.
What is being done to reduce deforestation?
Logging & replanting; education; ecotourism; international agreements; creating national parks.
how many species are there in the Amazon Rainforest
10% of Earth’s species.
how many trees in the Amazon Rainforest
Estimated 400 billion.
how much of the Amazon Rainforest has been cut down
0.17
Trees found in emergent layer of rainforests
40m or taller; supported by buttress roots.
Trees found in canopy of rainforests
Dense layer forming complete coverage; 10-30m tall; may include many hardwoods (e.g. mahogany); like an umbrella; busiest part of rainforest.
Trees found in under canopy of rainforest
Dark & humid; contains saplings between trunks of larger trees; more sparse vegetation; 5-10m high.
climate of the undercanopy in rainforests
Darker & more humid.
climate of the shrub layer in rainforests
Dark, warm, humid.
definition of desert
Area receiving less than 250mm rainfall, resulting in extreme aridity.
global distribution of worlds hot desert environments
Between 20-30 degrees North & South of equator (mostly in dry continental interiors); some coastal deserts exist (e.g. Atacama desert - South America, Namib desert - Africa).
how do ocean currents affect climate of desert?
Deserts on Western edge of continent have cold ocean currents along coast that cools air, making it harder to hold moisture, then it falls before reaching land.
how have fennec foxes adapted to the desert?
Thick fur on soles of feet (protect from heat of sand & traction); light coloured fur - reflects heat & camouflages; large ears - dissipate body heat; produce little urine; live in burrows during day to hide from heat.
Why are rain forests being cut down?
Farming/agriculture (cattle ranches); urbanisation/urban sprawl; development of infrastructure; to get raw materials (fruit, medicine, timber); mining; increasing population.
indigenous
Originating occurring naturally in a particular place.
why is the soil in rain forests low in nutrients?
Millions of years of weathering & torrential rain have washed most nutrients away.
adaptations of giant water lily
Large leaves - more sunlight & reduces competition; bottom of leaves covered in spikes - prevents being eaten; waxy top layer - as dry as possible to maximise gas exchange.
adaptations of a pitcher plant
Brightly coloured - attracts bugs; hairs - prevent creatures escaping (carnivorous); catches animals because soil is infertile.
adaptations of the tarsier
Huge eyes - nocturnal so easier to spot predators & prey; very large hands - tips of fingers are padded to climb trees easily.
adaptations of toucans
Colorful feathers - camouflage in tropical habitat; long & curved beak - reach deep into trees to get eggs & other food, so can grab food and prey; sharp claws - grip onto trees.
where is the Amazon Rainforest?
South America; 60% in Brazil, the rest is in Bolivia, Colombia, Ecuador, Guyana, Peru, Suriname, Venezuela & French New Guinea; across 9 countries in total.
Climate conditions of the Amazon Rainforest
Humid & warm; average temp of 27.9°C in dry season & 25.8°C in wet season; high relative humidity, average of 88% in wet season & 77% in dry season.
Causes of climate of the Amazon Rainforest
Lots of trees cause lots of transpiration & water vapour in air, forming many clouds; tropical coverage zone around equator causes low pressure & descending air.
how are trees adapted to live in the Amazon Rainforest
Grow tall in search of light; have large buttress roots to support trunk & absorb nutrients from thin leaf layer; thick bark - don’t need to be kept warm; smooth bark - water runs off easy; thick, waxy leaves - repel water; leaves with drip-tips - water can run off easily, so leaves don’t get too heavy.
challenges of living in the Amazon Rainforest
Climate change; mining; fires; deforestation; increase in CO2 emissions; biodiversity loss; agriculture; logging.
climate of rainforests
Warm, roughly 27°C all year; little temp variation; very wet (averages over 2000mm per year); very humid; wetter & drier season but rainfall every month.
how does latitude of rainforests contribute to their high temp
Along or near equator; solar radiation is more concentrated near equator.
why does the rainfall vary in rainforests?
Tilt of Earth’s axis means different areas get different amounts of energy at different times of year; there will be more evaporation where more energy, so more rainfall; these differences are the Intertropical Convergence Zones.
Trees found in shrub layer of rainforest
Small trees, especially near rivers; very little sun; dark, warm, humid; fallen leaves, dead plants & animals will decay quickly; 0-5m.
climate of the emergent layer in rainforests
Sunny, bright, less humid.
climate of the canopy in rainforests
Lots of sun; will block sun from reaching layers below.
layers of the rainforest
Shrub layer, under canopy, canopy, emergent layer.
factors affecting climate of deserts
Air pressure, mountains, ocean currents.
why is temp always so high in rainforests?
Latitude & altitude.
how does air pressure affect climate of desert?
At equator warm, moist air rises, air cools & clouds form, and rain falls over tropics, cool and dry air descends in deserts; high air pressure, low evaporation = few clouds, descending air.
how do mountains affect climate of desert?
Air is forced to rise over but as it rises, water vapour cools & condenses to form water droplets, falling as precipitation when heavy enough; other side of mountain is rain shadow, descending dry air.
what have desert plants adapted to?
Dry conditions; high temps; short periods of rainfall.
how have desert plants adapted to dry conditions?
They are xerophytes (able to survive in dry conditions, through deep roots & waxy cell walls).
how have desert plants adapted to high temps?
Some plants have most of their biomass underground so it’s cooler & waxy skin to stop transpiration.
how have desert plants adapted to short periods of rain?
Have very quick life cycle & will bloom quick after rain.
how have acacia trees adapted to the desert?
Short, fat trunks (store excess water); pyrophytic (fire resistant); long tap roots (can be 50m into ground vertical & horizontal) to get as much water as possible.
how have kangaroo rats adapted to the desert?
Don’t sweat/ have oily skin - reduce water loss; produce little urine; don’t need to drink (get water from food); live in burrows during day to hide from heat.
how have camels adapted to the desert?
Stretchy nostrils/long eyelashes - keep sand out; dry poo/ little urine (reduce water loss); thick fur on top (for shade), thick fur on stomach (heat loss); can go a long without water; large flat feet - spread weight on sand.
