Topic 7 Flashcards
What are the major biomes?
Tropical forest, Temperate forest, Boreal forests, Tropical grassland Temperate grassland, Deserts and Tundra.
Describe the distribution of biomes in the world:
The tundra is located furtherest from the equator, in high latitudes in the north and south poles. Boreal forest is located far north of the equator (50 to 60 degrees) in areas such as Canada and Russia. Grasslands (both tropical and temperate) are found slightly north and south of the equator in warm locations. Tropical forests are located close to the equator, in hot and moist areas. Deserts are found in very close to the equator, at the hottest locations (Africa, Australia).
Explain why these biomes are located where they are in the world:
The climate affects the areas that biomes form in. For example, tropical forests have lots of biodiversity because they are located in hot and damp areas, which are ideal for plant growth and decomposition (increasing soil nutrients). On the other hand, tundras have no plant life due to the extreme cold temperatures found furtherest from the equator.
What are the characteristics of these major biomes?
Tundra - Very Cold, no plant growth, very little animal species
Desert - Hot, minimal plant growth, few animal species
Temperate forest - Warm, reasonable plant growth, some animal species
Temperate grasslands - Warm, some plant growth, some animal species
Tropical forest - Hot, lots of plant growth, several animal species
Tropical grasslands - Warm, reasonable plant growth, some animal species.
Boreal forests - Cold, minimal plant growth, few animal species
How do local factors affect biome distribution?
- Mountains receive more precipitation (due to wind exposure) but as altitude increases the temperature drops.
- Soil acidity/alkalinity affects what types of plants can grow in the area (different plants thrive better in certain pH’s).
- Rock type (permeable/impermeable) and resistance affects how much water can reach the soil and how much the rock is eroded.
What are biotic and abiotic components in an ecosystem?
Biotic components are the alive elements living in an ecosystem (e.g: a bird) whilst abiotic components are non-living (e.g: sunlight).
How are biotic components of an ecosystem dependant on its abiotic components and how do they interact?
In order for plants in an ecosystem to grow, they require sunlight and water (abiotic), making them dependant on these resources. They interact through the plants absorbing these abiotic elements and creating/releasing other abiotic elements (e.g: photosynthesis releases oxygen).
List some ways in which the biosphere provides resources for the indigenous people:
- Tribes can use herbal medicines from plant extracts.
- People can eat food produced by plants, such as berries.
- Trees can be used to build small homes or as shelter to provide living space and protection.
In what ways is the biosphere being exploited?
As population size increases, so to does the demand for resources such as food and water, as well as wood, metal, plastic etc. In order to sate these increasing demands large companies chop down more trees, increase mining operations etc, all of which require space and destroy vegetation.
Explain how the biosphere regulates the atmosphere, the water cycle and maintains soil health:
Trees (which take up nutrients from the soil) produce leaf litter which decays/decomposes over time, returning nutrients to the soil and keeping a constant supply of nutrients in the soil. Furthermore, trees absorb carbon dioxide and release, helping to reduce the amount of carbon dioxide in the atmosphere. Lastly, trees maintain the soil as it protects it from getting dry from sunlight overexposure, keeping evaporation levels high as well as binding the soil together to prevent soil erosion and sediment reaching rivers.
What are the differences between Malthus and Boserup’s theories about the relationship between people and resources?
Malthus’ pessimistic theory dictates that once a population demand exceeds the supply of a vital resource such as food, a famine, war or disease will occur to lower the population and therefore demand, fixing the exceeding of supply. On the contrary, Boserup’s optimistic theory states that once a population demand exceeds that supply they will find ways to increase the supply to fill the demand using technology, without a population crash.
