Big-eared Rabbits

When the antelope rabbit sweats, it does so mainly through its ears, which are a good 20 cm long. These giant spoons give off excess heat to the environment. And this is vital for the rodent, because the antelope hare lives in the hot, dry deserts of Arizona and Mexico.

It can grow up to 70 cm long and weigh almost seven kilograms. This makes the antelope hare one of the largest of all lagomorphs. A quarter of its body surface is covered by its long spoons. They are not only good for hearing, but also for survival. By emitting heat through them, the hare protects itself against the heat in the deserts of North America. Nevertheless, the long-eared hare prefers to spend its days in the shade of rocks and sparse desert plants. Only in the evening does it go in search of food. In the twilight, it munches on grasses and herbs, leaves and cacti.

Far away – in Canada and Alaska – lives a close relative: the snowshoe hare. It has much smaller ears than the antelope hare so that it does not lose heat. On the other hand, it lives on a large foot: its legs are long and densely hairy on the soles, which makes them look like snowshoes. With them, he cannot sink in the deep snow of the north. He also adapts the colour of his fur to the seasons and the climate. In summer, the snowshoe hare wears dark brown, in winter white. This is how it camouflages itself from its numerous enemies: the fox, the wolf, the coyote and various birds of prey.

The snowshoe hare and the antelope hare have another trick against extinction in common and completely independent of the climate: like other hare species, they are very fertile and reproduce quite quickly.

The Saguaro National Park in Arizona

We call them Armleuchter cacti in German because they look like giant candlesticks. Where they thrive, in the southwest of the USA and in Mexico, they are called Saguaros. Growing several metres high, these impressive cacti are the emblem of Saguaro National Park in the southwest of the United States of America. The national park is part of the Sonora Desert, which stretches from Arizona far into Mexico. In this hot, dry desert climate, only plants that can withstand extreme heat and drought thrive. Besides various types of cacti, they include pines or junipers and even flowers such as lupines and gold poppies. The animal world has also adapted. The antelope hare, various bird species, rattlesnakes, lizards and tortoises are at home in this amazingly species-rich desert.

What are climate zones?

In the morning cloudy to partly cloudy with showers. In the afternoon the sun will shine, with temperatures between 16 and 22 degrees”, this may be the weather forecast for southern Germany. The forecast is interesting for us because the weather is constantly changing. It is different with the climate, because that remains. Climate means the average weather of a region over a longer period of time. For example, the climate at the equator is hot and humid all year round. At the North Pole, on the other hand, temperatures are freezing and there is little precipitation. Between the equator and the poles, there are areas where it can be very changeable, just like here. But why is it that the climate on Earth is so different?

The sun’s radiation is not equally strong everywhere on earth. How intensively it heats the earth depends on the angle of the sun’s radiation and thus on the latitude. Because the sun is almost vertical all year round near the equator, the earth is heated very strongly here. Towards the poles, the sun’s rays strike at an increasingly shallow angle: The same solar energy is distributed over an ever larger area. Therefore, the greater the distance to the equator, the cooler it becomes. This creates regions with different climates, the climate zones

According to the strength of the sun’s rays, four different climate zones can be divided on the mainland of the earth: The tropics around the equator, the subtropics (from the Latin word “sub” for “under”) between the 23rd and the 40th parallel, the temperate zone of our latitudes and the polar regions around the North and South Poles. Like belts, these climatic zones run in an east-west direction around the earth.

However, the climate does not only depend on the latitude, other influences also play a role. For example, there is snow on Mount Kilimanjaro even though it is in the tropics. The fact that its summit is icy is due to the fact that the temperature drops with increasing altitude. Mountain climates are therefore always cooler than lower-lying areas.

The distance to the sea also affects the climate: Water can store solar heat longer than land. It also warms up more slowly than the land. As a result, seawater acts as a buffer for temperatures. The climate is therefore mild near the coast. In the interior, this heat balance is lacking and a continental climate prevails, where temperatures fluctuate much more than in the maritime climate near the sea.

From rainforest to tundra – vegetation zones

Trees and deciduous forests can thrive well in cool and humid areas. Where it is particularly hot and dry, on the other hand, hardly anything grows: deserts form there. Only plants that are as well adapted to this extreme climate as cacti have a chance to survive here.

Plants depend on the climate: where which species are at home is determined above all by the temperature and the amount of precipitation. That is why there are many different regions on earth with specific plant communities: the vegetation zones. Because the type of vegetation depends on the climate, these vegetation zones, similar to the climate zones, run roughly parallel to the equator.

The typical vegetation zones include, for example, the rainforest in the ever-humid tropics. With increasing distance from the equator, the grasslands of the savannahs, on which trees and shrubs also thrive in isolated cases, are the typical vegetation. Towards the poles, the subtropics follow with deserts and semi-deserts, the special plants of the alternating and ever-humid subtropics, the deciduous and mixed forests of the temperate latitudes and the coniferous forests of the cold temperate zone. In the areas around the poles, only particularly hardy shrubs, mosses and lichens grow. This last vegetation zone before the polar desert of ice is called tundra.

The boundaries of the vegetation zones are not always easy to recognise; their transitions are fluid. This is also due to the fact that humans have an influence on the plant world: By clearing forests, cultivating the land and building cities, they change the original vegetation. If you want to describe which plants are actually growing at the moment, you also talk about ecozones.

Subtropics

In summer, many sun-seekers are drawn to Italy, Spain or Greece because it is warm and dry there. All these Mediterranean countries belong to the subtropical climate zone, which lies between the tropics and the temperate zone. But the subtropics do not only include the entire Mediterranean region with its hot, dry summers and mild, humid winters. As in the tropics, the subtropics also have different climates with their own plant communities in different places.

In the dry subtropics near the equator it hardly rains. Because of the great aridity, almost nothing grows here except extremely adapted plants like cacti. This zone is home to large deserts such as the Sahara in North Africa, the Atacama in northern Chile or the Namib on the west coast of Africa.

Towards the poles it gets wetter: the Mediterranean is quite dry in summer, but in winter areas of rain move in from the west. However, there is hardly any frost even in the cold season. This subtropical winter rain climate on the western sides of the continents is not only found on the Mediterranean, by the way. California and South Africa also have a Mediterranean climate. The vegetation has adapted to the climatic situation. Typical plants are those that can retain their foliage even in winter. Their leathery leaves can store water well and draw on it in times of drought. These hard-leaved plants include, for example, rosemary and the olive tree.

In the ever-humid subtropics, on the other hand, rain falls all year round. It rains particularly heavily in summer. Then monsoon winds blow in from the east, which have absorbed a lot of moisture over the sea and rain it back down over the land. Because of the high rainfall, the plants grow very luxuriantly there: the subtropical humid forests resemble tropical rainforests. Originally, such humid forests existed in the south-east of the USA, in East Asia or in northern Argentina. However, large parts of these forests were cleared to make room for agriculture.

Temperate zone

Freezing cold or scorching heat are rare here. Extreme temperatures are rarely measured in the temperate zone. Precipitation falls all year round: in summer as rain or hail, in the cold season sometimes as snow. Germany is also located in these temperate latitudes, which lie between the subtropics and the polar regions.

In the northern hemisphere, western and central Europe are part of the temperate latitudes, as well as the central part of North America and central Asia. This climatic zone covers a much smaller area in the southern hemisphere: New Zealand, south-eastern Australia, southern Africa and South America belong to it. More than a third of the world’s population lives in the temperate latitudes, especially the highly developed industrial nations such as the USA, Japan, China and many European countries.

Spring, summer, autumn and winter – distinct seasons are a special feature of the temperate zone. Because temperatures change with the rhythm of the seasons, vegetation has adapted. To survive the frost in winter, deciduous trees shed their leaves in autumn and form new ones in spring. Conifers are particularly well protected against severe cold by the wax layer of their needles. Deciduous and mixed forests are the typical vegetation in temperate latitudes.

The closer we get to the poles, the colder it gets. In this cold-temperate zone with its long winters, it is mainly conifers that grow because they are particularly well adapted to icy temperatures. In the northern hemisphere, there is therefore a broad belt of coniferous forests in large parts of Canada and Russia, also known as the taiga.

Typical for the temperate zone is: the further inland you go, the drier it gets. While it rains a lot all year round in Brest, France, on the Atlantic Ocean, it is much drier in Siberia, far inland on the continent. There, the temperature differences between summer and winter are also much higher. Such a dry climate with strong temperature fluctuations is called a continental climate. Because of the great aridity, hardly any forest grows here. In contrast, there are more steppes – also called prairies (North America) or pampas (South America), depending on the region. In some places it is so dry that semi-deserts and deserts have formed, such as the Gobi in Central Asia.