Topic 7 - People and the Biosphere (Global Ecosystems) Flashcards
What is the definition of an ecosystem?
A community of plants and animals interacting with the non-living environment.
What is the definition of a biome?
A large-scale ecosystem e.g. tropical rainforest.
What is the definition of the biosphere?
The living layer of Earth between the lithosphere and atmosphere
Define biodiversity
Biodiversity is the variety of all living organisms/the number of species in an area
Describe the climate of tropical forests.
(seasons, temperature, sunshine hours, precipitation)
HOT AND WET
1) There are no seasons - the climate is the same all year round.
2) It’s hot (typically between 20 - 28℃) only varying by a few degrees over the year). This is because at the equator the Sun is overhead all year round.
3) Because tropical rainforests are found at the equator, day length is the same (about 12 hours) all year round. This means the forests get lots of sunshine all year.
4) Rainfall is very high (around 2000 mm per year) and it rains every day, usually in the afternoon.
Describe the characteristics of tropical forests.
(plants, animals, soil)
1) PLANTS - most trees are evergreen to take advantage of the continual growing season. Plants grow quickly and are adapted to take in maximum light.
2) ANIMALS - the dense vegetation provides lots of food and different habitats, so there are lots of different species of animal, for example: gorillas, jaguars, tree frogs and sloths. There are loads of species of insects and birds.
3) SOIL - plants grow quickly and shed all year round. These decompose quickly due to the moist, hot climate, so there is a constant supply of nutrients in the soil, and these nutrients are cycled quickly.
Describe the climate of temperate forests.
(seasons, temperature, sunshine hours, precipitation)
MILD AND WET
1) Temperate forests have four distinct seasons.
2) The summers are warm and the winters are cool.
3) Days are shorter in the winter and longer in the summer - the hours of sunshine vary through the year.
4) Rainfall is very high (up to 1500 mm per year) and there’s rain all year round.
Describe the characteristics of temperate forests.
(plants, animals, soil)
1) PLANTS - the mild, wet climate supports fewer plant species than tropical forests, but more than boreal forests. Forests are often made up of deciduous trees that drop their leaves in autumn (e.g. oak), shrubs (e.g. brambles) and undergrowth (e.g. ferns).
2) ANIMALS - the mild climate and range of plants provides and habitats for mammals (e.g. foxes, squirrels), birds (e.g. woodpeckers, cuckoos) and insects (e.g. beetles, moths).
3) SOIL - plants lose their leaves in autumn, and the leaf litter decomposes quite quickly in the moist, mild climate. This means that the soils are relatively thick and nutrient-rich.
Describe the climate of boreal forests (taiga).
(seasons, temperature, sunshine hours, precipitation)
COLD AND DRY
1) Short summers and long winters.
2) In winter temperatures are below -20℃. In summer average temperatures are about 10℃.
3) Lots of daylight during the summer months, but little or none during the winter. Skies tend to be clear, so during the daylight hours there’s plenty of sunshine.
4) Precipitation is low - generally less than 500 mm per year. A lot of this falls as snow.
Describe the characteristics of boreal forests (taiga).
(plants, animals, soil)
1) PLANTS - most trees are evergreen, so they can grow whenever there’s enough light. Coniferous trees such as pine and fir are common, as are low-growing mosses and lichen.
2) ANIMALS - there are relatively few animal species in boreal forests because there is less food available and animals need to be adapted to the cold climate to survive. Animals that do live there include: black bears, wolves, elk and eagles.
3) SOIL - the cool, dry climate means that needles from the trees decompose slowly, so soils are quite thin, nutrient-poor and acidic. In some areas the ground is frozen for most of the year.
Describe the climate of tropical grasslands.
(seasons, temperature, sunshine hours, precipitation)
1) Distinct wet and dry seasons.
2) Temperatures are highest (around 35℃) just before the wet season and lowest (about 15℃) just after it.
3) They are found around the equator, so they have lots of sunshine all year round.
4) Low rainfall (800 - 900 mm per year)
Describe the characteristics of tropical grasslands.
(plants, animals, soil)
Rainfall is too low to support many trees which affects animals and soil.
1) PLANTS - consists mostly of grass, scrub and small plants, with a few scattered trees e.g. acacia
2) ANIMALS - They are home to lots of insects, including grasshoppers, beetles and termites. Larger animals include lions, elephants, giraffes, zebras and antelope.
3) SOIL - Grass dies back during the dry season, forming a thin, nutrient-rich soil, but nutrients are washed out of the soil during the wet season.
Describe the climate of temperate grasslands.
(seasons, temperature, sunshine hours, precipitation)
1) They have 4 seasons
2) Hot summers (up to 40℃) and cold winters down to - 40℃)
3) Because they’re further from the equator the amount of light they receive varies through the year.
4) They receive 250-500mm of precipitation each year, mostly in the late spring and early summer.
Describe the characteristics of temperate grasslands.
(plants, animals, soil)
Rainfall is too low to support many trees in temperate grasslands, which affects animals and soil.
1) PLANTS - consists mostly of grasses and small plants, and have very few trees.
2) ANIMALS - home to fewer animal species than tropical grasslands - mammals include bison and wild horses, and rodents such as mole rats.
3) SOIL - high temperatures in summer mean that decomposition is fast, so soils are relatively thick and nutrient-rich.
Describe the climate of deserts.
(seasons, temperature, sunshine hours, precipitation)
1) 2 main seasons - summer and winter
2) Hot desert temperatures range from very hot in the day (e.g. 45℃) to cold at night (below 0℃).
3) Hot deserts get more daylight during the summer than the winter. Because there is little cloud cover , they get lots of hours of sunshine each day.
4) Rainfall is very low - less than 250mm per year. It might only rain once every two or three years.
Describe the characteristics of deserts.
(plants, animals, soil)
1) PLANTS - plant growth is sparse due to lack of rainfall. A few plants do grow , e.g. cacti, thornbushes.
2) ANIMALS - relatively few animal species live in hot deserts - those that do are adapted to cope with the harsh climate. Animals that live there include lizards, snakes, insects and scorpions.
3) SOIL - the sparse vegetation means that there is little leaf litter, and the dry climate means that organic matter is slow to decompose. As a result, soils are mostly thin and nutrient-poor.
Describe the climate of tundra.
(seasons, temperature, sunshine hours, precipitation)
COLD, DRY CLIMATE
1) 2 seasons - summer and winter
2) Temperatures are low - around 5 - 10℃ during the summer and lower than - 30℃ in the winter.
3) Tundra is found at high latitudes, so it gets near-continuous daylight in the summer and little or no daylight in the winter. There is more cloud cover in the summer.
4) Precipitation very low - less than 250mm per year. Most of this falls as snow.
Describe the characteristics of tundra.
(plants, animals, soil)
1) PLANTS - the cold climate and lack of light in winter make it hard for plants to grow, and there are hardly any trees. Vegetation includes mosses, grasses and low shrubs.
2) ANIMALS - the cold climate and lack of vegetation means that relatively few animal species live in the tundra. Those that do include Arctic hares, Arctic foxes, mosquitoes and lots of birds. Some animals migrate south for the winter.
3) SOIL - the sparse vegetation produces little leaf litter, and the cold, dry climate means that organic matter decomposes slowly, so soil is thin and nutrient-poor. There is a layer of permafrost below the soil surface, which can stop water from draining away.
Name four factors affecting local biome distribution.
1) Altitude
2) Rock type
3) Soil type
4) Drainage
Define altitude
Height above sea level
Explain how altitude affects local biome distribution
Higher altitudes are colder, so fewer plants grow there, which also limits the number of animal species. This means there’s not much organic matter, so soils are thin or non-existent.
Explain how rock type affects local biome distribution
Some rocks are easily weathered to form soils, and different rock types contain different minerals. This affects how nutrient-rich the soil is. Some rocks are also permeable and others are impermeable affecting drainage.
Explain how soil type affects local biome distribution
More nutrient-rich soils can support more plants. The acidity and drainage of soils also varies, affecting the plants that can grow. E.g. peat soils are very acidic, so only acid-tolerant plants such as conifers can grow, and clay soils are sticky, so water can’t flow through flow through very easily.
Explain how drainage affects local biome distribution
If drainage is poor, soil gets waterlogged and only plants adapted to wet conditions can grow there. Very wet areas may be home to aquatic species of plants and animals.
