People and Biosphere Flashcards
what is an ecosystem?
A grouping of plants and animals that interact with each other and their local environment
what is a biome?
a large scale ecosystem
what is biotic?
the living components of an ecosystem: the plants and animals.
what is abiotic?
the non-living components of an ecosystem. eg. soil, rocks, water and atmosphere
what are the characteristics of the tropical rainforest?
- hot and wet all year
- dense forests with several layers of trees and plants competing for light
what are the characteristics of the tropical savanna?
- hot all year
- wet but always with a dry season
- tall grasses and some drought-adapted shrubs and trees
what are the characteristics of the deserts?
- very hot all year but with cool nights
-low rainfall
-plants are scarce and have water-storing features, spines instead of leaves and extensive root system
what are the characteristics of the temperate grasslands?
- hot in summer and very cold in winter
- short grasses with very few trees and bushes
what are the characteristics of the temperate forest?
- warm summers and precipitation all year
-deciduous trees such as oak
what are the characteristics of the boreal forests?
- mild summers and very cold winters
-low precipitation mainly in summer
-coniferous trees such as pine
what are the characteristics of the tundra?
- below 0’ for most of the year
-low precipitation and short daylight hours in winter
-very few plants mostly miss and lichens, trees are rare and stunted
why is the tropical rainforest hot and wet?
- it is near the equator so bevause the sun is directly ahead all year and the suns rays have a shorter atmospheric distance to travel it is hotter.
- it is situated in the inter-tropical convergence zone so it causes high precipitation
why are deserts warm in the day and cold at night?
- sinking air warms and so can hold more moisture preventing cloud formation and creating high pressure so when it turns to night it is more cool and heat escapes as their is no clouds to ‘blanket’ it
how does latitude affect ecosystem?
- temperatures drop the further you are from the equator due to the curvature of the earth
-closer to the equator the sun shines directly overhead so heat is more intense. Also, the sun is shining at a rigjt angle so it has less distance to travel through. - Closer to the poles the sun is at a lower angle in the sky so heat is dispersed across a larger area.
How do pressure belts affect biomes?
- In low pressure areas their is rain as air rises, cools and condenses forming rain
- In high pressure areas it is dry as air sinks
How does altitude affect the location of Biomes?
Temperatures fall as height increases. Hills and mountains are also exposed to wind.
How does rock type affect the location of biomes?
Some rocks are permeable and soak up water and others are impermeable and don’t let water soak through.
How does soil type affect location of biomes?
Different plants grow better in different types of soil
How does the biosphere help the composition of the atmosphere?
-Plants take in and store carbon dioxide from the atmosphere as they grow, but release it back when they die and decay.
-Forests are important carbon stores so destroying forests releases carbon dioxide and prevents it from being taken in and stores.
How does the biosphere help soil health?
- Healthy soils contain nutrients, plants remove nutrients from the soil as they grow and pass through the ecosystem food web.
- Dead plant and animal matter (litter) then decays and returns to the soil.
Breaking this pattern by deforestation leads to declined soil health.
How does the biosphere help the hydrological cycle regulation?
- Plants especially forests, intercept precipitation, slowing it down.
- Plants also absorb water through roots and prevent surface runoff by slowing the water down
Why is there an increase in demand for resources?
- The world population has grown exponentially more people = more demand.
- Over time the amount of food enegery and water has risen as cities have streetlights, people use water for toilets and showers and people are getting wealthy and can afford cars and computers using energy.
What is the Malthusian theory?
Thomas Malthus believed that human population would grow faster than the resource supply. When this occurred, carrying capacity has been reached and there would be a point of catastrophe, war, famine and epidemics. This then decreases the population returning to balance.
What was the Boserupian theory ?
Esther Boserup suggested as population increased human ingenuity and innovation woukd find ways do increase production to meet demand.
