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Question: Many fungi and lichens are threatened with extinction due to the destruction of habitats. Should they come under legal protection by their inclusion on lists of endangered species? 

Answer: It's a tricky moral issue you've raised and you will need to ask a number of questions and need to be clear in your own mind which side you are on, then to defend your answer.

Some definitions are probably helpful too. Are they an endangered species? - Remember extinction is actually a normal process in the course of evolution.

Why are the habitats being destroyed? - road building, house construction, land drainage, pollution etc are all causes - what can be done about these?

Introduced diseases, parasites, and predators against which native flora and fauna have no defenses have also exterminated or greatly reduced some species.

To what extent are fungi and lichens part of the food chain and if they were to disappear, what would the effect be on other species?

Fungi, which are not green plants because they do not contain chlorophyll, cannot make their own food and so must rely on other things. Most fungi feed on the remains of dead plants and animals. They are decomposers and change dead things into humus which is rich in nutrients that plants use as food. Soil with plenty of humus in it grows strong plants. Soil is a habitat for creatures such as worms and insects - so any disturbance affects them too. These are a rich supply of food for birds and small animals, which would disappear. Eventually you get to the top of the food chain - man -so what then?

The food chain is a very delicate balance and any alteration can have considerable effect later higher up the food chain.

Think of the build up of toxins, for example.

The build up of toxins in the food chain is an example of biomagnification.

The toxins that become magnified are those that do not readily break down and are usually retained in fatty tissue. An example of such a toxin is DDT.

If we think of insects that have been poisoned by DDT and die, and the bodies end up in, for example, a lake, several things will happen. The insects sink to the bottom of the lake, where the DDT is picked up by organisms at the bottom of the food chain. These might be algae, which will only pick up a minute quantity of DDT, say 1 nanogram. Next, plankton may eat a thousand of these algae, which means it now has accumulated 1 microgram of DDT. A small fish could now eat a thousand of the plankton, which means it has now accumulated 1 milligram. Larger fish will eat a number of the smaller fish and in turn will increase the amount of the DDT in their bodies. Eventually, a bird, such as an osprey, which is higher up the food chain, will eat a number of fish and increase the amount of toxin up to a considerable number of grams. The effects can now be quite devastating, with the possibility of the toxin weakening eggshells which can result in chicks being crushed in the nest, and of course, eventually no more ospreys.

So, the concentration at the end of the food chain can be millions what it was initially in the environment. What started off as relatively unharmful can become a killer due to the cumulative effect of the toxin.

A balance is needed between plants and animals - does this justify legal protection of fungi and lichens?

A lack of law enforcement might give some people the notion they can destroy anything in sight.

Legislation also gives publicity and legitimacy to a cause - many people are probably not aware that such common, everyday things as fungi are affected by habitat destruction and do not appreciate the consequences of such a loss.

What about the financial burden of the legislation to include something in a list of endangered species? What does this involve? Do the costs outweigh the benefits of protection of species? Governments always consider finance.

Is there any conflict between large corporations and conservationists? e.g. The construction provides many jobs - so what's a few fungi to these people? Are they the ones who need the legislation?

It's not easy, but a very important issue! Don't forget your conclusion.

It might be best to try to put something of both sides of the argument - it shows you have thought seriously about the problem.



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