Ecosystems. Biomes. Habitats

Ecosystems vary in size. They can be as small as a puddle or as large as the Earth itself. Any group of living and nonliving things interacting with each other can be considered as an ecosystem.

Within each ecosystem, there are habitats which may also vary in size. A habitat is the place where a population lives. A population is a group of living organisms of the same kind living in the same place at the same time. All of the populations interact and form a community. The community of living things interacts with the non-living world around it to form the ecosystem. The habitat must supply the needs of organisms, such as food, water, temperature, oxygen, and minerals. If the population's needs are not met, it will move to a better habitat. Two different populations cannot occupy the same niche at the same time, however. So the processes of competition, predation, cooperation, and symbiosis occur.

Habitats, then, are specific to a population. Each population has its own habitat. For example, a population of ants has its own habitat.

Several populations may share a habitat. For example, in a small pond several aquatic populations may co-exist in the same water at the same time. An aquarium is a good example of a shared habitat.

Biomes are ecosystems where several habitats intersect. A definition for biome is "a living community characterized by distinctive plant and animal species and maintained under the climatic conditions of the region." The Earth itself is one large biome. Smaller biomes include desert, tundra, grasslands, and rainforest.

Biomes occur naturally, but people can also create controlled biomes. For example, you can integrate several small populations in a small space and observe what happens. A famous manmade biome is Biosphere 2.

The energy cycle within biomes, habitats, and ecosystems determines which populations survive and which die. All living things need energy. Ultimately, the sun is the source of all energy in an ecosystem. Different species have different functions: producers, consumers, decomposers, and scavengers.

Habitats must also supply water for all living things to survive. Their needs are met through the water cycle.

Since energy and water are vital to the survival of an ecosystem, a system of conservation is needed. In many ecosystems, the conservation of resources is natural. Life substances, for example, are recycled in the ecosystem. The exchange of carbon dioxide (given off by animals) and oxygen (given off by plants) is actually a process of conservation. The waste of one species becomes food for another. When resources become limited, the conservation process becomes more urgent and more visible with an increased need for recycling.

If conservation efforts fail, species become endangered and extinction can occur. A species becomes endangered when there is not enough habitat available to support all members of the population. When the habitat vanishes, and all members of the population die, then the species is considered extinct.

Notes:

puggle – лужа producer – производитель (продуцент)

intersect – пересекаться consumer – потребитель (консумент)

ultimately – в конечном счёте decomposer – разрушитель (редуцент)

exchange – обмен scavenger – животное, питающееся падалью

waste – отходы urgent – насущный, срочный

recycling – переработка extinction – исчезновение

available – доступный vanish - исчезать

2. Find in the text the equivalents to the following word combinations:

взаимодействующие друг с другом; внутри каждой экосистемы; одного и того же вида; потребности организмов; лучшее место обитания; в маленьком пруду; совместное проживание; рукотворный биом; источник всей энергии; система сохранения; возросшая потребность в переработке; жизненно важный для выживания экосистемы

3. Select the statement that best expresses the main idea of the text.

a) Any group of living and nonliving things interacting with each other can be considered as an ecosystem.

b) A habitat is the place where a population lives.

c) Biomes, ecosystems and habitats are different levels of species existence.

d) All living things need energy.

4. Is it true or false? Correct the wrong statements.

1) A population is a group of living organisms of various species living in the same place at the same time.

2) If the population's needs are not met, it will become extinct.

3) Two different populations can occupy the same niche at the same time

4) All of the populations interact and form a biome.

5) The habitat must supply the needs of organisms, such as food, water, temperature, oxygen, and minerals.

6) Biomes are ecosystems where several communities intersect.

7) Biomes occur only in nature.

8) The energy and water cycles within biomes, habitats, and ecosystems determine which populations survive and which die.

9) When resources become limited, the conservation process becomes more urgent.

10) When the habitat vanishes, and all members of the population die, then the species is considered endangered.

5. Identify the functions ticking the right columns.

species	producer	consumer	decomposer	consumer (scavenger)
Lichen Owl Bacteria Fox Salmon Squirrel Bear Wolf Lemming Algae Grass Hyena Oak Penguin Griffon-vulture

6. Retell the text.

7. Find the information about an endangered species on the Internet. Retell it. Use the following questions as a plan:

- What is the species’ habitat?

- Why is it endangered?

- How many are left?

- What can be done to save it?