TREES

There are many reasons why tree shapes differ. A tree growing in poor soil may be stunted due to lack of nutrients, and a tree growing right next to an apartment building may have more leaves on the side facing the sun. Different kinds of trees have their own unique form, but the form that any tree has is also affected by the environment where it grows.
Sunshine and water are both essential for a tree to survive, and both influence tree height, crown shape (for example, a round treetop or the cone shape of a pine tree), and the form of leaves.
Some tree species grow quite tall and receive much sunlight. But what about those trees left in the shadows? Many trees collect sunlight that is filtered through the leaves of taller trees. These shaded understory trees survive by gathering indirect sunlight or sun flecks that break through openings in the canopy. A rounded crown seems to work best for gathering filtered, understory sunlight, which comes from many different directions.
The shape of the tree's crown also has a lot to do with where it lives. Nearer to the equator, the noontime sun is almost directly overhead all year. Tall trees with flat treetops (or crowns) are very common in this part of the world because the flat shape helps expose more of their leaves to the direct, overhead light.
Up nearer to the Arctic circle, the sun is never directly overhead and is usually quite low in the sky. Trees in this part of the world tend to be cone-shaped (think of pine trees), with leaves from the top of the tree to the bottom, to make the most of this sunlight.
Finally, many of the trees up nearer to the Arctic circle (like spruce, pines, and fir trees) have needles, partly because needles are especially adapted to cold, dry climates. Needles retain water better than broad-leafed trees like oaks and maples.
INTRODUCTION
Have you ever felt like you needed your own space? Sometimes we all need to be alone. Plants and trees need to have their own space, too. How do you get your own space? You can walk away or shut your door, but what can plants do? They can't walk or run anywhere. Plants have a different way of getting their own space. They use allelopathy.
Allelopathy is a chemical process that a plant uses to keep other plants from growing too close to it. Some plants that use allelopathy are black walnut trees, sunflowers, wormwoods, sagebrushes, and trees of heaven.
Some pine trees are allelopathic. When its needles fall onto the ground, they begin to decompose . The soil absorbs acid from the decomposing needles. This acid in the soil keeps unwanted plants from growing
Why Plants Need Space, Too
All living things need certain resources to live and grow. What does your body need to be healthy? Plants need sunlight, nutrients, water, and air. The roots bring nutrients and water from the ground to the tree. The leaves absorb the sun's rays for energy. When plants don't have enough space, they cannot meet their needs. So, the plants protect their resources by using allelopathy.
Here are four major reasons that trees need their own space:
Fire
Water
Roots
Sun
Plants need to protect themselves from harm. Fire is always a threat to plants in the wild. If trees are too close to each another, fire can spread from one to another very easily. So, trees create space for themselves in order to remain safe.
<>In some areas, there is not a lot of water. The fewer plants there are around you, the more water your roots can pull from the soil.
If you are a plant, you need lots of dirt for your roots to grow in. So, you want to have as much dirt to yourself as possible. One way to do this is to make everyone else's roots die off using allellopathy.
Plants need sun to live. If other plants grow nearby, their shade means less sunlight for the tree. If only you could think of a way to make the other plants move away...
How plants keep other plants away
Allelopathy is a chemical process that a plant uses to keep other plants out of its space. There are several types of chemical alleopathy. In one kind, the plant that is protecting its space releases growth-compounds from its roots into the ground. New plants trying to grow near the allelopathic plant absorb those chemicals from the soil and are unable to live. A second type of allelopathy releases chemicals that slows or stops the process of photosynthesis . An allelopathic plant may also release chemicals that change the amount of chlorophyll a plant has in it. When a plant's chlorophyll levels are changed, it cannot make the food it needs, and the plant dies.
There are several ways in which an allelopathic plant can release its protective chemicals:
Volatilization
Allelopathic trees release a chemical in the form of a gas through small openings in their leaves. Other plants absorb the toxic chemical and die.
Leaching
All plants lose leaves. Some plants store protective chemicals in the leaves they drop. When the leaves fall to the ground, they decompose. As this happens, the leaves give off chemicals that protect the plant.
Exudation
Some plants release defensive chemicals into the soil through their roots. Those chemicals are absorbed by the roots of other trees near the allelopathic one. As a result, the non-allelopathic


What is a mountain?
The dictionary defines a mountain as that which is ‘higher and steeper than a hill’. It is a landform that extends above the surrounding terrain in a limited area. Mountains usually have steep, sloping sides and sharp or slightly rounded ridges and peaks.
Generally, mountains are landforms that rise above 2000 feet. Mountains exist on every continent and even beneath our great oceans. Formed through varying causes, there are several distinct types of mountains.
Mountains are home to approximately one-tenth of the world’s people, cover one-fifth of the earth’s land surface, and occur in 75 percent of the world’s countries. More than half of the world’s fresh water originates in mountains, and all the world's major rivers are fed from mountain sources
Uses of MountainsClimbers and tourists visit them for the scenery. Farmers graze their animals on them. Water authorities make reservoirs and pump the water to towns and cities. Forestry companies grow coniferous forests and harvest wood on them.
People
10% of the world's 6 billion people live on Mountains. The Alps are the most densely populated mountain area in the world. Eleven million people live in the Alps.
People as well as other animals and plants have adapted to living in the mountains. The South American Uru tribe have larger hearts and lungs to breather the thin air at high altitudes.
How do mountains affect the people who live near them?
Mountains can make travel difficult.Mountains can be very difficult to cross. They are often rugged and filled with forests and wild animals, such as bears and wolves. They may have no natural 'passes,' or easy places to cross the mountains. Mountains can also be hard to climb or may have ice or snow or glaciers that make travel dangerous.
All this means that crossing over mountains - to trade goods or to fight a war - can be tough to do. Sometimes, people who live surrounded by mountains feel very isolated from the world around them. It is just too difficult to cross over to other lands.
Tourism
Mountains can aid tourism and bring in money for the people who live there. More than 50 million people visit mountains each year. Many mountain towns around the world depend on tourists to support them. People in the town provide food and lodging for tourists who come to enjoy the nearby mountains.
Mountains can be places for leisure activities. Many people like to ski on mountains. Other people like to climb mountains. Some people like to just visit mountains to take photos and admire their beauty.
Tourists are attracted to mountains for many reasons:
the climate and clean air,
varied topography,
beautiful scenery,
local traditions,
simple life styles,
sports that require steep slopes or winter snow
Sport-based tourism has boomed over the past 30 yearsTypical mountain activities include:
hiking,
skiing,
snow boarding,
climbing,
bird watching
rafting
Impact on the EnvironmentAlthough tourism has it advantages it can have serious impact on the environment, the people who live there and the local economy. As more and more people visit the mountains, whether to climb or simply to trek through the valleys, the chances of the environment being permanently damaged become ever greater.
Advantages of Tourism
Creates jobs
Encourages local crafts
Improved living standards
Disadvantages of Tourism
Higher prices of land and food
Pollution from traffic
Erosion
Litter
More crowded
Trees felled to supply timber and fuel wood
Lost of cultural identity among the mountain people
How are mountains formed?
Mountains are created over long periods of time by tremendous forces in the earth Mountains are formed by volcanism, erosion, and disturbances or an uplift in the earth's crust.
The Earth's crust is made up of 6 huge slabs called plates, which fit together like a jigsaw puzzle. When two slabs of the Earth's crust smash into each other the land can be pushed upwards, forming mountains. Many of the greatest mountain ranges of the world have formed because of enormous collisions between con
What different types of Mountains are there?
There are five basic kinds of mountains: dome, fold, fault-block, volcanic, and dome mountains. These different types of mountain names not only distinguish the physical characteristics of the mountains, but also how they were formed.
Dome Mountains Dome mountains are the result of a great amount of melted rock pushing its way up under the earth without folding or faulting resulting in a rounded dome. As the dome is raised above its surroundings erosion occurs, and as a result of erosion, peaks and valleys are formed.
Fold Mountains Fold mountains are formed when two plates collided head on, and their edges crumbled, much the same way as a piece of paper folds when pushed together. Examples of fold mountains include Himalayas in Asia, the Alps in Europe and the Andes in South AmericaFind out more....
Fault-block Mountains - These mountains form when faults or cracks in the earth's crush force some materials or blocks of rock up and others down. Instead of the earth folding over, the earth fractures and blocks are stacked. Examples include the Sierra Nevada mountains in North America and the Harz Mountains in Germany.
Volcanic Mountains Volcanic Mountains are formed when molten rock, or magma deep within the earth, erupts, and piles upon the surface. Examples of Volcanic Mountains include Mount St. Helens in North America and Mount Pinatubo in the Philippines.Find out more ....
Plateau Mountains (Erosion Mountains)These are mountains that are really plateaus that have worn down from erosion. The dictionary describes these as large areas of ‘high levels’ of flat land.
Mountains around the World
Mountains and mountain ranges are found on every continent in the world.
Live! World Mountain Cams
AsiaAsia is the largest continent in both size and population covering almost 1/3 of the world's land area and it has about 3/5 of the world's people. It has some of the world's highest mountains, longest rivers, largest deserts, plains, and plateaus, and thickest forests and jungles.
NepalMount Everest, is the highest mountain on the earth (measuring from sea level). It rises 8,848 meters above the sea, on the border between Nepal and China.
Mt. Everest has three names. In the Nepali language it is called Sagarmatha (Head of the Sky), and in Tibetan it is called Chomolangma (short for Jomo Miyolangsangma, the name of a Tibetan goddess who is one of the Five Sisters of Long Life).
To go on an interactive tour of Mount Everest visit Everest Interactive.
Another great site about Everest is the Nova site
K2, is the second highest mountain on the earth. It rises 8,611ms above sea level.
Japan: Mount Fuji, (highest mountain in Japan) 3,776msIt is an isolated volcano, located only 50 miles southwest from Tokyo.
Europe
Argentina: Aconcagua in Andes 6,960msAconcagua is the highest mountain in the Western hemisphere, located in western Argentina, near the Chile border.
Britain: Ben Nevis, Scotland 1,343ms
Ben Nevis - highest mountain in Great Britain Snowdon - highest mountain in Wales Scafell Pike - highest mountain in England (978 metres ~ 3208 feet high)Kinder Scout - highest peak in the Peak District
Greece: Mount Olympus, Athens 2,917msMount Olympus is the highest mountain in Greece.
Turkey: Mount Ararat, 5,165msMount Ararat is a snow-capped volcanic cone, located in extreme northeast Turkey.
Photographs of the Mountains of Europe
Map showing the mountains of Europe
Africa Africa is the second largest continent in area covering about 1/5 of the world's land area and it has the third largest population. Volcanic activity created most of Africa's highest mountains. The 2 tallest peaks are Mt. Kilimanjaro at 19,340 ft. and Mt. Kenya at 17,058 ft. They are both extinct volcanoes. Even though both mountains rise near to the equator, they have glaciers and are covered with snow most of the year.
Tanzania: Mount Kilimanjaro, 5,895msThe highest mountain in Africa, located in Northeast Tanzania, near the Kenya border.
Kenya: Mount Kenya, 5,199msThe second highest mountain in Africa. Like Mount Kilimanjaro, it is an extinct volcano.
Australia:
Mt Kosciuszko - Australia, 2228 metresThe highest mountain in Australia, located in the extreme southeast corner of the continent. Located between Melbourne and Sydney in the Australian Alps
Ayers Rock, Northern Australia, 335ms
Mount Bruce, Australia. 1227ms
What is a Mountain Range?
A mountain range is a group or chain of mountains that are close together. Mountain ranges are usually separated from other mountain ranges by passes and rivers.
What is the longest mountain range in the world?The Andes Mountains, which stretch more than 4,500 miles (7,200 km) through seven South American countries, form the longest mountain range in the world.
Well known mountain ranges
Himalayas The Himalayas are the highest mountain range in the world.
The Himalayas, literally translated as Land of Snow, is the great mountain system of Asia, home to the highest (tallest) peaks in the world. They form a 1500 mile broad crescent through Northeastern Pakistan, Northern India, Southern Tibet, Nepal, Sikkim and Bhutan. There are more than 30 peaks of the Himalayas each rising to heights of 7,620 m (25,000 ft) or more.
The Himalayas is one of the youngest mountain ranges in the world.
Alps The Alps is a vast mountain system in south central Europe, extending over 750 miles (1,200 km) through South France, North Italy, Switzerland, Liechtenstein, Germany, Austria and Slovenia. The Andes chain is generally about 200 miles (300 km) wide, except in Bolivia, where it expands to twice that width.
The Alps includes several hundred peaks and glaciers, including numerous peaks over 12,000 feet, with Mont Blanc highest at 15,771 feet.
Rockies The Rocky Mountains are a vast mountain system in Western North America, extending north-south from Canada to New Mexico, a distance of about 3,000 miles (4800 km). The highest peak is Mount Elbert, in Colorado, which is 14,440 feet (4401 m) above sea level.
Andes The Andes Mountains are the longest and one of the highest mountain ranges in the world. They are located in South America and stretch 4,500 miles (7,200 km) from north to south, along the west coast of the continent.
The Andes are the second highest Mountain Range in the world with many peaks rising over 20,000 feet.
KarakoramThe Karakoram is a great mountain range in Northeast Pakistan and Northern India, near the Chinese border. It extends 300 miles southeastwardly and includes many of the world's highest peaks, and many of the world's longest glaciers.
Some of the mountain ranges found on each continent
Antarctica: Antarctic Peninsula, Transantarctic Mountains The highest mountain, Vinson Massif in the Ellsworth Mountains, peaks at 4897 m.
Africa: Atlas, Eastern African Highlands, Ethiopian Highlands
Asia: Hindu Kush, Himalayas, Taurus, Elburz, Japanese Mountains
Australia: MacDonnell Mountains
Europe: Pyrenees, Alps, Carpathians, Apennines, Urals, Balkan Mountains
North America: Appalachians, Sierra Nevada, Rocky Mountains, Laurentides
South America: Andes, Brazilian Highlands
All rivers start at the highest point in an area. As the river flows downstream, it gains more water from other streams, rivers, springs, added rainfall, and other water sources.
What is a river?A river is fresh water flowing across the surface of the land, usually to the sea. It flows in a channel. The bottom of the channel is called the bed and the sides of the channel are called the banks.
Where do rivers begin and end?Rivers begin in mountains or hills, where rain water or melting snow collects and forms tiny streams called gullies. Gullies either grow larger when they collect more water and become streams themselves or meet streams and add to the water already in the stream. Find out more about the different sources of rivers.
How are rivers formed?When one stream meets another and they merge together, the smaller stream is known as a tributary. It takes many tributary streams to form a river.
What do Rivers provide?Most settlements were built along major rivers. Rivers provide us with food, energy, recreation, transportation routes, and of course water for irrigation and for drinking.
Why are rivers important?
WaterRivers carry water and nutrients to areas all around the earth. They play a very important part in the water cycle, acting as drainage channels for surface water. Rivers drain nearly 75% of the earth's land surface.
HabitatsRivers provide a habitat and food for many of the earth's organisms; their powerful forces create majestic scenery
Transport Rivers provide travel routes for exploration, commerce and recreation.
FarmingRiver valleys and plains provide fertile soils. Farmers in dry regions irrigate their cropland using water carried by irrigation ditches from nearby rivers.
EnergyRivers are an important energy source. During the early industrial era, mills, shops, and factories were built near fast-flowing rivers where water could be used to power machines. Today steep rivers are still used to power hydroelectric plants and their water turbines.
Rivers Glossary
tributary
a stream flowing into or joining a larger stream
distributary
any of the numerous stream branches into which a river divides where it reaches its delta
upstream
moves toward headwater (up the regional slope of erosion)
downstream
moves toward mouth of river (delta)
delta
a large, roughly triangular body of sediment deposited at the mouth of a river
meander
a broad, looping bend in a river

Nature
Nature (also called the material world, the material universe, the natural world, and the natural universe) is all matter and energy, especially in its essential form. Nature is the subject of scientific study. In scale, "nature" includes everything from the universal to the subatomic. This includes all things animal, plant, and mineral; all natural resources and events (hurricanes, tornadoes, earthquakes). It also includes the behaviour of living animals, and processes associated with inanimate objects.
Contents
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1 Nature outside Earth and its atmosphere
2 Life
3 Chemicals
4 Matter and force
5 Earth
6 The supernatural
7 Metaphysics
8 The natural and the artificial
9 Related concepts
10 Mother Nature
11 Notes
12 See also
13 External links
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Nature outside Earth and its atmosphere
Events and phenomena outside Earth and its atmosphere are in the natural science of astronomy.
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Life
Life, the characteristics and behaviors of organisms, how species and individuals come into existence, and the interactions they have with each other and with their environment are all in the natural science of biology.
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Chemicals
The structure, properties, composition, and reactions of chemical elements and compounds are part of the natural science of chemistry.
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Matter and force
The behaviour and interactions of matter and force are a part of the natural science of physics.
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Earth
Everything relating to the planet Earth is a part of earth science.
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The supernatural
Main article: Supernatural
Most people believe in the existence of a non-material world in a sense beyond that of just mental experience. They rather believe in supernatural beings and in a supernatural reality absolutely different in kind to that of the natural world. If such a reality exists, many scientists and others assert that it is beyond the reach of science. Science has been very successful in bringing apparently inexplicable and supposedly supernatural phenomena within its scope.
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Metaphysics
In philosophy, the view that the material world of atoms, animals, gravity, stars, wind, microbes, etc., actually exist independently of our observations of them is termed realism; the opposing view is called idealism.
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The natural and the artificial
A distinction is often drawn between the "natural" and the "artificial" (="man-made"). Can such a distinction be justified? One approach is to exclude mind from the realm of the natural; another is to exclude not only mind, but also humans and their influence. In either case, the boundary between the natural and the artificial is a difficult one to draw (see mind-body problem). Some people believe that the problem is best avoided by saying that everything is natural, but that does little to clarify the concept of the "artificial". In any event, ambiguities about the distinction between the natural and the artificial animate much of art, literature and philosophy.
Another approach is to distinguish natural processes and artificial (man-made) processes. In this viewpoint, a process is deemed to occur either at the behest of man, or not. For example, flipping a light switch might illuminate a room, or perhaps a sunrise might illuminate that room. In this viewpoint, the sunrise would be termed a natural process; the decision of a human being to flip the light switch would be termed an artificial illumination, in contrast. In this viewpoint, artifice (art or literature) is clearly the result of willful human action; furthermore, the act of stating a philosophical position could also a willful action (and hence at the behest of man), whether or not the content of the philosophy were to be about science.
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Mother Nature
Main article: Mother Nature
The word nature comes from the Latin word, natura, meaning birth or character (see nature (innate)). In English its first recorded use, in the sense of the entireity of the phenomenon of the world, was very late in history in 1662; however Natura, and the personification of Mother Nature, was widely popular in the Middle Ages and can be traced to Ancient Greece in origin. The pre-Socratic philosophers of Greece had invented Nature when they abstracted the entirety of phenomenon of the world into a single name and spoken of as a single object: Natura. Later Greek thinkers such as Aristotle were not as entirely inclusive, excluding the stars and moon, the "Supernatural", from the concept of Nature. Thus from this Aristotilian view—nature existing inside a larger framework and not inclusive of everything—Nature became a personified diety, and it is from this we have the origins of a mythological goddess Nature. Later medieval thinkers also did not see Nature as all-inclusive, considering her as the world that lay beneath the heavens and above the underworld. For the medieval mind she was only a personification, not a goddess. The modern concept of Nature, all inclusive of all phenomenon, has returned to its original pre-Socratic roots, not a personification or deity except in a rhetorical sense.1