geography - the living world, tropical rainforests, deserts

ecosystem

a community of plants and animals which interact with each other and with their non-living environment

biome

very large ecosystem

biotic

living things

abiotic

non-living things

producer

an organism that uses light energy and photosynthesis to produce sugars

consumer

an organism that gets its energy by eating other organisms (producers and other consumers)

food chain

a community of organisms where each member is eaten in turn by another member

food web

a community of organisms where there are several food chains

nutrient cycling

where organisms take the minerals necessary for growth from soil or water, before passing them on through the food chain and then back to the soil and water

decomposer

organism that gets it’s energy by decomposing dead organic material in an ecosystem

what are 2 examples of decomposers

bacteria, fungi

natural system

a system in ecology that has inputs, outputs, energy flows, and transfers

transpiration

moisture going back into the atmosphere from vegetation

evaporation

all the moisture going back into the atmosphere

3 link food chain

when a primary consumer eats a producer, which then gets eaten by a secondary consumer

4 link food chain

when a primary consumer eats a producer, which then gets eaten by a secondary consumer, which then gets eaten by a tertiary consumer

what happens when you move through the food web and what does that mean?

energy is lost at each stage, which means less consumers can be supported

what do consumers do to the energy taken in from a food chain?

they waste or use it

what are more complex: food web or food chain?

food webs

where do decomposers work?

all levels of the food web

are there more producers or tertiary consumers?

producers

what are 6 key biomes

1. grassland

2. tundra

3. tropical rainforest

4. temperate deciduous forest

5. polar

6. hot desert

where are tundras distributed/located (2)

• high latitudes, above 60° N

• N europe, alaska, N canada

what is the seasonal weather like in Tundra biomes (3)

• winters are very cold

• summers are brief

• little rainfall

how is the environment like in Tundra biomes (3)

• barely any trees

• vegetation like moss, grass and shrubs

• permafrost

what is permafrost

a layer of permanently frozen ground

what are the 2 types of grassland

savannahs and temperate grasslands

where are savannahs located/distributed

found between the tropics

what is the seasonal weather like in a savannah (2)

• distinct dry and wet seasons

• rainfall is low

what is the environment like in savannahs (2)

• grasses

• a few scattered trees

where are temperate grasslands located/distributed

higher latitudes (then savannahs)

what is the seasonal weather like in temperate grasslands (2)

• more variation in temperature

• very little rainfall

what is the environment like in temperate grasslands (2)

• no trees

• only grass

where are temperate deciduous forests found

in the mid latitudes

what is the seasonal weather like in temperate deciduous forests (4)

• 4 distinct seasons

• summers are warm

• winters are mild

• rainfall all year

what is the environment like in temperate deciduous forests (2)

• trees (which lose leaves in winter)

• lots of vegetation

where are polar biomes located/distributed

around the north and south poles

what is the seasonal weather like in polar regions (4)

• very cold

• icy

• dry

• very dark for several months of the year

what is the environment like in polar regions

not much grows

where are hot deserts located/distributed

between 15° and 35° N and S of the equator

what is the seasonal weather like in hot deserts (3)

• very hot during day

• very cold at night

• very little rainfall

what is the environment like in hot deserts (3)

• shrubs

• cacti

• sandy soil

where are tropical rainforests located/distributed (2)

• around the equator

• between tropics

what is the seasonal weather like in tropical rainforests

hot + wet all year

what is the environment like in tropical rainforests (2)

• lush forests

• dense vegetation

what latitude is the tropic of cancer at

23.5° North of the equator

what latitude is the tropic of capricorn at

23.5° South of the equator

what is Epping Forest

a temperate deciduous forest located in SW england

Epping forest is a …

SSSI (site of special scientific importance)

example of a food chain in epping forest

shrubs/grasses → worm → rabbit → fox

what is pollarding?

cutting a tree’s branches off at the top

what is coppicing?

tidying up trees by cutting off stems at the bottom

trees found in epping forest? (4)

• oak

• breech

• hornbeam

• elm

how many lakes and ponds are there and why is this important

100+ → provides important habitats for many plants and animals

no. of species of fungi in epping forest?

700 (common due to large amount of deadwood)

how is epping forest sustainably managed

• recreation controlled within forest (designated visitor areas e.g. car parks, visitor centre)

• paths for walking → protect forest for future gens

• vegetation cut back to alert deer of traffic + reduce collisions → protects current + future deer populations

• cattle reintroduced in some areas (grazing supports growth of some flora) → helps support flora growth

abiotic and biotic things are …

interdependent

saharan desert soils are called …

entisols

what are nomads?

people who don’t have a set home

what is a desert?

a region that receives less than 250mm of rainfall per year

what is adaption?

changing to suit the environmental condition changes

what is rainfall like in deserts

it varies a lot. it might only rain once every 2/3 years

what is temperature like in deserts

very hot in day (45°C) and very cold at night (5°C)

what is the soil like in deserts (3)

• shallow with a coarse, gravelly texture

• soil is infertile

• soil is dry

what is plant life and vegetation like in deserts (3)

• growth is sparse due to lack of rainfall

• e.g. of plants are cacti, thornbushes and shrubs

• plants have a short life cycle and only appear when it rains

what animals are there in deserts (2)

• lots of reptiles, e.g. lizards, snakes, insects, scorpions

• mammals tend to be small and nocturnal

people in deserts (2)

• tend to be nomads mostly

• very few people

how do plants and animals depend on eachother in deserts

plants get nutrients from soil. animals that eat plants digest the nutrients. when animals excrete, their dung contains seeds and nutrients, helping plants reproduce

how is biodiversity in deserts?

very low

there is a sparse number of plants…

so the desert can only support low-density populations of animals

how does the scarce supplies of water affect deserts, animals and plants

the little rainfall is quickly drained away by the coarse desert soil. animals and humans have to find ways of coping, e.g. constantly moving to new places, digging deep wells

how do people grow crops in deserts

through irrigation (artificially watering the land). they draw unsustainable amounts of water from wells.

how does irrigation affect other plant species and animals

it lowers the level of water underground. this reduces the amount available to other plants, so there are less plants for animals to eat

adaptations of plants in deserts? (4)

• plant roots

• succulent plants

• small leaves/spines

• seeds only germinate when it rains

how do plant roots help desert plants survive in the conditions (2)

either:

• long to reach very deep water supplies

• wide to catch lots of rainfall

how do succulent plants survive in the conditions (3)

• large, fleshy stems for storing water

• thick waxy skin to reduce transpiration

• some have sharp spines and toxins to stop animals stealing water from their stems

how does having small leaves or spines help desert plants survive in the conditions (1)

low surface area, reducing transpiration

how does having seeds which only germinate when it rains help desert plants survive in the conditions (1)

the plants grow, flower and release seeds in just a few weeks, making sure they only grow when there’s enough water to survive

adaptations of animals to survive in deserts (4)

• nocturnal

• have large limbs/ears

• able to tolerate high temps

• store large amounts of fat

how does being nocturnal help animals to survive in desert conditions (1)

can stay cool by burrowing underground/sitting in shade during day

what is an example of an animal that is nocturnal in deserts

fennec foxes

how does having large limbs/ears help animals to survive in desert conditions

provides a large surface area to lose heat from

how does being able to tolerate high body temperatures help animals to survive in desert conditions (2)

• can tolerate higher temps

• examples: lizards, snakes, desert iguanas

how does being able to store large amounts of fat help animals to survive in desert conditions

larger mammals can store fat, allowing them to break it down into water when needed

example of animals that store fat

camels (in their humps)

how are camels adapted for deserts? (5)

• store fat in their humps

• triple eyelids

• long eyelashes

• they can close their nostrils

• large, flat feet

how does having triple eyelids, long eyelashes and being able to close nostrils help camels

keeps sand out of their eyes and nose

how does having large, flat feet help camels

stops them from sinking into the sand

where is biodiversity + human population highest in deserts (2)

• small areas around ephemeral (temporary) ponds or rivers

• along desert margins

endemic

unique

what do these areas contain

a high proportion of species that are endemic to the desert

what does development around desert margins result in

habitats being divided up by roads. this threatens animals that migrate over large distances to find food and water e.g. desert bighorn sheep

what is the effect of global warming on deserts and animals

makes them hotter and drier

what is the effect of global warming on animals in deserts

animals (e.g. lizards) migrate to cooler areas. animals that can’t migrate are on the decline, or risk of extinction.

what is the world’s largest desert

sahara desert

how big is the sahara desert?

9,000,000 km²

where is most of the water found in the sahara?

seasonal or intermittent streams

around … different animal species in the sahara desert

70

opportunities of economic development in the sahara desert (5)

• oil and gas extraction

• solar energy

• tourism

• mineral resources

• farming/water irrigation

what is an opportunity of oil and gas extraction? (2)

• 40,000 jobs

• 60% of it’s economy comes from this industry