My Science School

Moving Crust

As the plates of the Earth’s surface move towards each other, one plate may rise over the other one. The one which goes up forms mountains and the one which goes down is slowly melted below the Earth’s surface. Where two plates move away from each other, magma is free to escape. It solidifies to form rock, and a ‘mid ocean ridge’ or a ‘volcanic island’ is formed.

 

 

 

Folding

Movements in the Earth’s plates can also cause the Earth’s surface to buckle and split. Where the surface splits and slips, a ‘fault’ is produced. Where the surface buckles, a ‘fold’ is formed. Many familiar features of the landscape are caused by folds and faults, and these can often be seen in layers of rocks at seaside cliffs. The diagram shows some of the features that can be produced in these ways.

 

          Our lifecycle is closely related to ecology. Austrian geologist Eduard Suess first studied this relationship nearly a century ago. The word “ecology”, however, was derived from the Greek words “Oikos” meaning the house and logos meaning study.

          Now the question arises what actually “ecology” means? Ecology is the study of animals and plants in their natural surroundings or environments and how each species fits into its ecosystem. An ecosystem is a community of plants and animals spreading over a certain area together with the soil and other non-living materials. Therefore, the whole earth can be considered as a large ecological unit. Within an ecosystem, the organisms make up the balance with the environments.

          We all know that the most important factor for any organism is its source of energy or food. Thus within any such system a complex pattern of feeding relationship which we call food-chain, is built up to maintain the ecological balance. For instance, plants are a primary source of food and energy — the herbivores obtain their foods by eating plants. In their turn, herbivores are played upon by carnivores, which may also be a source of food for other carnivores.

          A typical example of an ecosystem is a pond, a desert or a forest. Within such an area are the major factors determining the type of ecological system that develops? In any ecological system, each organism however large or small plays a vital role in maintaining the stability of the community. Within this system carbon, nitrogen, oxygen and hydrogen (in water) are continually being recycled, through a number of processes. These are known as Carbon cycle, Nitrogen cycle and Photosynthesis.

          Over millions of years nature has moved towards the overall creation of a stable ecological balance. Natural changes such as adaption to the slow-changes tend to be gradual. But man is often responsible for causing sudden ecological imbalances through activities like deforestation; polluting the atmosphere, rivers, lakes and seas; by rapid industrialization or sometimes through the outbreak of a new disease. The effects of such types of change can be fast and irreversible. Upto now these changes have not been too serious except in some areas like disturbances of carbon cycle in the atmosphere. This is seen as a serious threat that may lead to the Global warming to change the ecology and thus an impending danger to the humanity all over the world.

          However, there is an increasing awareness of what could happen if a worldwide disturbance in ecological balance could not be checked in time.

 

 The major biomes of the world are: Tundra, coniferous forest, deciduous forest, grass lands and Savannas Chaparral, tropical rain forest and deserts. Major biomes of the world.

Biosphere is a term used to describe the parts of the earth and the thin layer of air above its surface that supports life. It is limited to the waters of the earth, a fraction of its crust and the lower regions of the atmosphere. It is also the part where solar energy is used to bring about photosynthesis and other chemical and physical charges. 

It is a broad natural assemblage of plants and animals shaped by common patterns of vegetations and climate. Some examples of biomes are forest biomes, desert biomes, grass land biomes or tundra biomes etc. 

The biotic factor concerns the organic variable affecting an ecosystem. For example, the changing population of elephants and its effect on the African Savana.

 The living components of biosphere such as plants, animals etc. are called biotic components. The non-living components of biosphere such as water, air, stones, etc. are called abiotic components. 

Habitat is defined as a localized environment in which an organism lives and which provides for all or almost all of its needs. 

The term food pyramid is used to describe the quantities of materials that pass from one kind of eater to another. The word pyramid is used because the amount of energy associated with the food material becomes smaller at every link or upward step.

All food chains begin with green plants because they are the only living things that can produce their own food. Green plants produce food by the process of photosynthesis.

 

The gradual but continuous change in a community is called ecological succession. If one community disappears, a different kind of community develops in place of the old one. 

 

Animals living in trees are called arboreal such as monkey.

 

Plants that grow on other plants using them only for support are called epiphytes. They have no roots in the soil. Epiphytes do not parasitize the plants they grow on.

 

Camouflage is the disguise used by animals to hide from their enemies. Men also use camouflage, particularly in wars. Most animals use camouflage to hide from predators or other animals that prey on them. Camouflaging is done by adopting matching colour to the surroundings, so that one looks like a part of it.

An animal which obtains food by hunting other animals is called a predator.