5. Read the text and think over the best title for each paragraph. What is ecosystem?

1. Term ecosystem refers to community of biotic and abiotic elements as well as processes that are influencing on behavior and life of certain unit in defined natural habitats. Every ecosystem has its characteristic biotic and abiotic elements. Entry of new elements to certain ecosystem has often very negative effects, and more often than not causes extinction of some species that used to be important parts of this ecosystem. Therefore it is really vital to try to reduce the input of new species as much as possible, because once these new species are introduced to certain ecosystem they tend to change it, often by endangering original species.

2. Humans shouldn't be really messing with nature's selection, especially in ecosystems with many different species because nature is the one that knows best. The secret of the nature selection is in forcing species to constant adaptation where only the strongest survive. However unlike the humans, the nature knows where exactly does certain animal and plant species belong. Human intervention to a certain ecosystem often results in only negative effects because we still have to learn so much different things to be able to compete with mother nature.

3. Process of natural selection usually lasts very long, therefore giving species enough time to completely adapt to new conditions. This is the main reason why natural selection is always better than the selection caused by human intervention. Convention on biological diversity that was ratified by 175 countries has important role in preservation of environment and current ecosystems. This Convention through its articles defines protection of ecosystem, natural habitats and preservation of diversity of species in their natural surroundings. This Convention defines ecosystem as "dynamic complexity of plants, animals, communities of microorganisms and their lifeless environment in interaction as one functional community".

4. Term ecosystem was for the first time used in publication of British ecologist Arthur Tansley in 1935, and the term itself was coined by his fellow colleague Roy Clapham, five years before. The recent research, where the team of more than 1000 scientists worked on evaluation of Earth's ecosystems has special place in studying the ecosystem. Results of this comprehensive research were anything but positive, and scientists concluded that people have violated ecosystems in last 50 years more than ever before in the entire history of the Earth.

biotic and abiotic elements – живые и неживые элементы

nature's selection – естественный отбор

6. Put the verbs in the right form and translate the text. Less fishing means more corals

Corals recently (experience) serious decline in population mostly because of climate change which is not only major culprit for coral bleaching events but also (contribute) to the rise of extreme weather events such as hurricanes which are also causing huge damage to coral reefs.

The researchers already (involve) into very lively discussion about the possible solutions to protect coral reefs from climate change. The latest proposal (come) from the University of Exeter in a form of less fishing. The researchers at the University of Exeter (believe) that by establishing marine protected area which could stop people from fishing would help corals survive the effects of a changing climate by more than 50 years.

Corals play extremely important role in proper functioning of the marine food chain so their loss (cause) huge damage to marine biodiversity leading to irreversible changes in many marine ecosystems.

Corals (be) extremely vulnerable to even the slight increases in sea temperatures. The scientists (calculate) that a temperature increase of just one degree Celsius above average for a few weeks is enough to kill off 95% of individual corals. Many scientists already (issue) warning that entire coral population (disappear) by the end of this century if the world fails to massively reduce greenhouse gas emissions.

According to this latest discovery one effective way to help corals cope with climate change would be to protect the fish that live around Caribbean coral reefs. Why are fish so important for survival of corals? It is because there are many fish species such as parrotfish which graze on the algae which competes for space with corals. With less algae around coral reefs can recover more quickly. The researchers (show) that protecting parrotfish (give) coral more time for recovery, and time is certainly the most important factor in equation of how to save corals.

The success of coral reefs conservation (play) a vital role in preserving the marine biodiversity for years to come. Conservation managers need all the help they can get because they have very limited amount of options available to them, particularly if the world fails to agree on new international climate deal. Protecting fish species such as parrotfish might just give corals enough time to escape from the brink of extinction.