Fragile Environments Flashcards
What is a fragile environment?
An environment vulnerable to change which which struggles to recover from said change, whether naturally or artificially induced
What is an ecosystem?
A system with complex and dependent interactions between living and non-living things
What is a biome?
A collection of similar ecosystems
What is the distribution of tropical rainforests?
- Found very close to the equator, with over 6% of the earth being covered by them
- Specific places include Brazil, Thailand and the DRC
What is the climate of tropical rainforests?
- Very hot (27-30 degrees)
- Wet (2000-3000mm)
- Accomodates more than half of worlds species
What is the distribution of hot deserts?
- 30 degrees north and south of the equator (though not directly on the equator)
- They cover 1/5 of the worlds land
- Specific places include the Saharah desert in Niger, Chad, Libya etc. and the Arabian desert
What is the climate of hot deserts?
- Extreme heat during the day (50 degrees), but very cold in the night (0 degrees)
- Extremely dry (less than 250mm)
What is the distribution of tundra biomes?
- 60-70 degrees north of the equator
- There are very few found south due to the lack of land in this area
- Specific places include Canada and Russia
What is the climate of tundra biomes?
- Extremely long, dark and cold winters (constantly below zero), though warm summers
- Very little rainfall (200mm per year - less than desert) due to low temperatures so little evaporation, but snow and ice provide some ground moisture
- Often little vegetation due to freezing temperatures
How and why does latitude affect temperature?
- The further away from the equator, the colder it is
- This is because the infrared radiation from the rays of the sun are able to hit the equator much more directly and more concentratedly, but as the earth curves away from the equator, the sun rays become more and more diffuse resulting in colder temperatures
What causes the climate of tropical rainforests?
- Very hot as they are located on the equator
- The heat causes all of the moisture on the ground to evaporate
- The air will cool and condense as it rises (low pressure), eventually falling over the rainforest and causing heavy rainfall
The humidity and water orginates from the dense vegetation and their transpiration
What causes the climate of hot deserts?
- The air which rose over the equator is now dry as precipitation has just occured
- It will therefore be blown to either side as part of the Hadley cell, where it falls (high pressure)
- This means that the deserts will be very dry as the descending air contains no moisture, but still hot due to their proximity to the equator
- The lack of vegetation and humidity in the air means very little heat is stored during the day, so nights are very cold
What are the four natural causes of climate change?
- The eruption theory
- The sunspot theory
- The cosmic materials theory
- The orbital theory (Milankovitch theory)
What is the eruption theory?
- Volcanic eruptions produce large amounts of ash and sulphur dioxide, spreading out in the atmosphere and reflecting sunlight
- This reduction can cool temperatures by 0.5-1 degrees
What is the cosmic materials theory?
- Large celestial bodies hit the earth every 50000 years, causing huge amounts of dust to cover the sky
- The ash and dust block sunlight, causing cooler temperatures
What is the sunspot theory?
- The sun’s output fluctuates, evidenced by darker spots present on the sun’s surface indicative of a higher concentration of solar activity
- This area of higher concentration can be directed to earth, causing localised or global temperatue increases overtime