Desert Description The seasons are generally warm throughout the year and very hot in the summer. The winters usually bring little rainfall. Temperatures exhibit daily extremes because the atmosphere contains little humidity to block the Sun’s rays. Desert surfaces receive a little more than twice the solar radiation received by humid regions and lose almost twice as much heat at night. Many mean annual temperatures range from 20-25° C. The extreme maximum ranges from 43.5- 49° C. Minimum temperatures sometimes drop to -18° C.
Location Deserts occur in five of the world's seven continents. North America's Sonora and Chihuaua deserts, situated in the south-west corner of the continent, extend into Mexico, while the Great Basin, covering most of the states of Utah and Nevada, is home to the infamous Death Valley, and the Great Salt Lake Desert. Further south, in the states of Arizona and California, lie the Mojave or High Desert and the Colorado or Low Desert. The North American deserts are renowned for their spectacular landscapes and searing heat.
Climate Hot and dry. These are the terms that characterise the desert climate in most people's minds, but is this an accurate depiction? As a general rule, areas subject to an average rainfall of less than 100mm a year can be classed as deserts. Sometimes a broader classification is used whereby deserts are split into three categories - semi-arid, arid and hyper-arid. Areas of the first kind receive less than 600mm of rainfall a year, areas of the second kind receive less than 200mm, whilst rainfall in hyper- arid desert regions never exceeds 25mm.
Climate But low average annual rainfall is only half the story. Not only do deserts experience very little rain, but to make matters worse, this small amount is highly irregular, both in terms of time and space. Sometimes an area of desert will be without rain for years and then, seemingly for no reason at all, a few large storms will provide enough rain in a short period to bring the average annual rainfall back to normal. Desert storms can be extremely localised, centring upon one area and leaving adjoining parts entirely dry. These are some of the factors that contribute to making deserts some of the most inhospitable environments on the planet.
Plants Water is essential for all plants, so survival in arid environments is a real challenge. However, some of the ways in which desert flora have adapted are ingenious. Generally, they either avoid or endure periods of low rainfall. Ephemeral or annual plants survive periods where water is in short supply because their seeds germinate only after heavy rain, grow rapidly, and live their whole life-cycle in just a few days. These plants often produce large, brightly coloured flowers to attract the insects that are essential to their pollination.
Animals If the desert is an inhospitable environment for plants, then it is even more so for animals. Shortage of water, lack of food, and extremes of temperature are just some of the obstacles that animals must overcome if they are to survive. However, all types of animal life are found in the world's deserts, from the smallest protozoa right up to large carnivores. Even fish are found in some parts of the North American desert!
Where maximum daily temperatures are consistently high, animals are at risk from overheating and water loss. To avoid this problem, animals will either spend most daylight hours in the shade of rocks or vegetation, or they will burrow into the sand where the temperature remains almost constant. The other alternative is to adapt to the high temperatures. The sections below look in more depth at the different strategies adopted by the various kinds of animal: insects reptiles birds mammals Animals
Rainforest Description About 420 million years ago, during the Silurian Period, ancient plants and arthropods began to occupy the land. Over the millions of years that followed, these land colonizers developed and adapted to their new habitat. The first forests were dominated by giant horsetails, club mosses, and ferns that stood up to 40 feet tall.
Rainforest Life on Earth continued to evolve, and in the late Paleozoic, gymnosperms appeared. By the Triassic Period (245-208 mya), gymnosperms dominated the Earth’s forests. In the Cretaceous Period (144-65m mya), the first flowering plants (angiosperms) appeared. They evolved together with insects, birds, and mammals and radiated rapidly, dominating the landscape by the end of the Period. The landscape changed again during the Pleistocene Ice Ages—the surface of the planet that had been dominated by tropical forests for millions of years changed, and temperate forests spread in the Northern Hemisphere.
Location All the Rainforest of the world are located in: central America, southeast Asia, Middle Center of Africa, north and some parts of South America.
Climate The climate of the area becomes drier with the loss of the vegetation which acts as a "sponge" to hold on to the moisture. Having less cloud cover means the increase in temperatures. Both the burning of the trees and their reduced number increases the concentration of carbon dioxide. The extra carbon dioxide is believed to contribute to global warming, which in turn is blamed for the rise in sea level.
Animals The rainforest is home to more than half of the world's animals. Colorful and unusual animals dwell in all four layers of the forest. All types of creatures are represented, from tiny insects to large mammals. Come learn about some of these animals in the rainforest by clicking on one of the animals below.
Animals Billions of animals, birds, and insects live in the tropical rainforest. Why do living things love to live in this environment? It is because they can find all the food they need to live. They can also find the kind of habitat they need to make a safe home and raise their young. Here are a few animals and insects from the tropical rainforest.
Plants Most ferns grow well in dappled shade. Plant them with the fern's crown clear of the soil. Newly planted ferns should be watered regularly until they are well established. Once established they can be quite drought tolerant. Many ferns will cope with morning or late afternoon sunshine, but only a few will grow in intense mid-day sun. (See our list of sun tolerant ferns.) Ferns are not particularly bothered by pests. Slugs will occasionally eat tender new growth; they especially like Hen and Chickens fern. Put out slug bait, but generally no need for other pesticide sprays on these ferns.sun tolerant ferns
Location Saltwater biome can be a ocean or a sea that its located around the world there are only 4 oceans in the world the Pacific Ocean, the Atlantic Ocean, the Arctic Ocean and the Indian Ocean. The Pacific Ocean is located west of North and South America, the Atlantic Ocean is located between Africa and south and North America, the Arctic Ocean is located north of Europe, North America, and Asia.
Climate There is clear evidence that Earth's surface temperature has risen by about 0.5°C over the last 100 years. However, there is some uncertainty as to the causes of this temperature increase, as well as what its short- and long-term effects will be on regional and global scales. Predictive computer models indicate that given a steady rise in levels of greenhouse gases, such as carbon dioxide, there will be a corresponding increase in surface temperatures.