# Basic Geography/Ecosystems

What is an ecosystem? Well, before we try and answer this question, we need to answer what a climate is to help us. So what is a climate? Weather is unpredictable: even in the Sahara, a hot, dry place, it can snow- the characteristic of a cold, wet place; and in the U.K it can be hot and sunny! But a climate is more long-term; it is the Average weather over a long period of time. For example, the Amazon is usually warm and wet, so it has a warm and wet climate. But extremes (unusual weather for the area) are also important; for example, if you wanted to build a house, you would want to know what the 'Worst weather in a 100 years is', so you can install the right defences. Ecosystems are areas that have similar characteristics on a large-scale.

## World climatic zones

The Earth is divided into a number of World Climatic Zones, Ecosystems. There are a number of ecosystems that we are going to look at and describe some features.

### Desert

Deserts have a hot, dry climate, with under 250mm of rainfall of every year. With almost no humidity or cloud cover, the Deserts suffer temperature extremes: hot days and cold nights. They are usually found in the Middle latitudes, away from the moisture of the tropics and the cold of the Arctic; but the Arctic is a desert itself'. It is known as a 'cold desert'- dry enough to be a desert but without hot daytime temperatures. Creatures living in the desert are very adaptable, as they must be able to cope with extremes of temperature and the dry conditions. The Cactus is a desert plant, without real leaves so it saves reason, and prickles for the same reason and for protection against desperately hungry animals.

### Rainforest

Rainforests are usually more South from Deserts, but temperatures are not as hot in the day, thanks to moisture, cloud cover and tree cover. Temperatures are usually more balanced, unlike the extremes of a Desert. There are lots of vegetation and wildlife, as there is never a lack of water and temperatures are balanced. But a cactus wouldn't be able to live in a rainforest, as it is designed to get as much water as possible- not an ideal skill in a Rainforest!

### Temperate

Temperate Rainforests have even more life than their tropical counterparts, despite being less famous. The U.K and most of Europe and North America has a Temperate climate- with warm summers, cool winters, and rather balanced rainfall- these conditions are very stable, therefore being home to many forms of life. Temperate life doesn't normally need any specific features to help it cope with its surroundings (unlike a cactus). Hedgehogs are temperate animals with fur- a good insulator from the cold winters and spikes (like a cactus) to protect itself' from potential predators.

### Polar

Polar ecosystems are cold and dry- dry meaning very little snow, despite the cold. Cold air holds less water vapour than warm air, making snow a rare event even up North. Polar animals have to be very adaptable to survive- especially in the Arctic where ice is commonly melting. The Polar Bear is a very adaptable animal- it can swim, has a thick layer of blubber for warmth, and it is designed for hunting, instead of having trouble finding the little vegetation there is.

### Mountainous

Vostock Station in Antarctica experienced the coldest ever recorded temperature because of its' polar conditions and its high altitude. As well as the cold as you increase in altitude, the lack of oxygen is another factor that limits life on the mountain. However, the mountain can offer factors like camouflage that support life. The habitat of a mountain changes with altitude: high up there is a snow-line, with a permanent layer of snow that almost nothing can exist in. Some plants can live over 5000m up a mountain, but they must have extremely good adaptions.

## Other Ecosystems

There are a number of other important ecosystems to mention, including:

### Ocean

We should perhaps call our planet Planet Ocean, as over half our planet is ocean. Life in the Ocean has existed far more than in land, and life there is perhaps even more amazing. Corals and fish cramp the warm, tropical waters of the Coral Reef; and we know less about the bottom of the ocean than the surface of the moon: where freezing temperatures, extreme pressure and very hardy- but rare and scattered- life exists, clinging to any possible thing to sustain them: Hydrothermal Vents.

### Urban

Why not turn off your PSP and look out your doorstep? The Urban landscape offers more than being bored stiff! There are plenty of Pigeons scavenging littered chips and Frogs croaking round the waterside. But factors such as Pollution and Acid Rain make the Urban Landscape hard to gain a foothold on.

## Quiz

* What is the Ecosystem the photograph is set in?
* What is the climate of the ecosystem?
* Which latitudes does this ecosystem tend to be found?
* Name a plant in the picture and explain how it adapts to its habitat

## Answers

* Desert
* Dry with extremes of temperatures
* Mid-latitudes
* (one example) A Cactus adapts to its' habitat by having little leaves which reduces evaporative loss.

## References

Weather, Reader's Digest