Evolutionary biology, one of the Biology Topics, investigates the mechanisms behind the origin and diversification of species.
What is a habitat? Give Examples.
All the living organisms (plants and animals) prefer to live in those places which are best suited to their needs. The place (or surroundings) where a plant or animal lives is called its habitat. Actually, habitat means a dwelling place (or a home). A habitat provides food, water, air, light, shelter (protection), and a place for breeding to the plants and animals living in it.
In fact, a habitat provides everything to the organisms which they need to live. Different types of plants and animals live in different habitats. Some of the examples of habitats are : Deserts, Mountain regions (or Hills), Forests, Grasslands, Garden, Fields, Soil, Homes, Tree, Pond, Lake, River, Ocean (or Sea) and Sea-shore. A plant or an animal is adapted to survive in its habitat.
All the habitats can be divided into two main groups :
- Terrestrial habitats, and
- Aquatic habitats.
A land based habitat is called a terrestrial habitat (The word “terra” in Latin language means “land” or “ground”). Thus, the plants and animals which live on land are said to live in a terrestrial habitat. Some of the examples of terrestrial habitats are : Desert, Mountains (or Hills), Forest, Grassland, Garden, Field, Soil and Homes. A cactus plant and camel live in a dry land called desert. So we can say that cactus and camel live in a terrestrial habitat (called desert).
A water based habitat is called an aquatic habitat (The word “aqua” in Latin language means “water”). Thus, the plants and animals which live in water are said to live in an aquatic habitat. Some of the examples of aquatic habitats are : Pond, Lake, River, Swamps (an area of waterlogged ground) and Oceans (or Sea). A lotus plant and fish live in water, so we can say that a lotus plant and a fish live in an aquatic habitat (say, a pond).
The types of habitats vary from organism to organism. The plants grow better and survive longer in a particular habitat to which they are adapted. Some plants prefer to live in hot and dry areas of land. For example, cactus plant grows and survives well in the hot and dry areas of desert.
This is because cactus is adapted to live on very little water for long periods of time. So, the habitat of a cactus plant is desert. On the other hand, some plants prefer to live in water. For example, lotus plant grows and lives in the water of a pond. It cannot survive without sufficient water. So, the habitat of lotus plant is a pond. Some of the common plants and their habitats are given below :
The fish is an animal which lives in water. It cannot live without sufficient water. So, the habitat of a fish can be pond, lake, river or sea (because all these places contain water). On the other hand, camel is an animal which is adapted to survive on very little water for long periods of time. So, the habitat of a camel is the desert. And a bird’s habitat might be a tree. Some of the common animals and their habitats are given below:
Several kinds of plants and animals may share the same habitat. For example, the pond habitat has many types of plants such as: Algae, Hydrilla, Water-lily, Water-hyacinth and some Weeds. The pond habitat has also many types of animals such as: Fish, Frogs, Turtles, Water-spiders, Water-skaters, Snails, Dragon flies, Kingfishers, Herons and Ducks in and around it. Even the microscopic animals like ‘Amoeba’ and ‘Paramecium’ are found in the pond habitat. In fact, all the plants and animals which are in and around a pond of water share the same habitat: the pond. The pond habitat is shown in Figure.
Though a large number of living organisms share the same habitat (say, a pond), but their food habits are different. Due to this, the organisms face less competition for food. This helps in the survival of all the organisms in a habitat.
A habitat does not consist of only living organisms. In a habitat, soil, water, air, light, temperature and many other components of physical environment are also present. Thus, a habitat includes both biotic and abiotic components of the environment. The habitat also includes the interactions between the biotic and abiotic components of the environment.
Biotic Components
The term “biotic” means “living”. So, the living things in a habitat are its biotic components. The living things in a habitat are plants, animals and micro-organisms. So, we can say that the biotic components of a habitat are : Plants, Animals and Micro-organisms. In other words, the living things such as plants, animals and micro-organisms in a habitat are known as its biotic components.
Abiotic Components
The term “abiotic” means “non-living”. So, the non-living things in a habitat are its abiotic components. The various non-living things in a habitat are soil, rocks, air, water, sunlight and temperature, etc. So, we can say that the abiotic components of a habitat are : Soil, Rocks, Air, Water, Sunlight and Temperature, etc. In other words, the various non-living things such as soil, rocks, air, water, sunlight and temperature, etc., are called the abiotic components or abiotic factors of the habitat.
The abiotic factors are necessary for the existence of plants and animals living in a habitat. For example, the soil provides various nutrients (such as nitrogen) for the growth of plants. Air provides carbon dioxide gas to the plants for making food. Water is also required by the plants to make food. Sunlight provides energy to the plants to make food by the process of photosynthesis. And temperature (or heat) is required for the germination of seeds to grow into new plants.
Activity
We know that many plants grow from seeds. So, we will now describe an activity to show the effect of some abiotic factors on the germination of seeds to form young plants. Take a small heap of moong seeds.
- Keep some dry moong seeds in a sunny room (where sunlight is available)
- Keep some moong seeds completely submerged in water for a few days.
- Soak some moong seeds in water for a day, then drain out wait
(a) Keep some soaked and wet moong seeds in sunlight for a lew days.
(b) Keep some soaked and wet moong seeds in a completely dark place for a few days.
(c) Keep some soaked and wet moong seeds in a very cold place like a refrigerator (or with ice around them) for a few days.
After a few days we will observe that the dry moong seeds do not germinate at all showing that water (or moisture) is necessary for the germination of seeds to grow into plants. The moong seeds kept completely submerged in water also do not germinate showing that air is also necessary for the growth of plants.
The wet moong seeds kept in sunlight germinate and grow maximum (but those kept in dark do not grow much) showing that sunlight is necessary for the growth of plants. The wet moong seeds kept in a very cold place (like a refrigerator) grow very, very slowly showing that temperature (heat or warmth) is necessary for the growth of plants.
From this activity we conclude that the abiotic factors such as water, air, sunlight and temperature (or heat) are very important for the growth of plants. In fact, these abiotic factors are very important for the existence of all the living organisms : plants as well as animals.