Do we need species diversity/stability or are only a few species vital for the functioning of the ecosystem?

Answer 1

am i seeing double or have i just answered this question(forgive me for the paste)

Changes made to the LAW OF HARMONY (or Equilibrium)

What matters remains to be seen ,
that it will change things is certain.

Everything in Nature is a balanced existence between species of both flora and fauna,that has taken many thousands of years to reach the present point of balance.

To add to this with foreign species again of either flora or fauna sets a change in motion.As well as taking components out .

They once sprayed for mosquito`s on the banks of the Danube and all of the life in the woods disappeared ,the mosquito`s being an important part of the food chain for many birds reptiles etc.

We all know about the rabbits and deer in Australia and New Zealand ,each specie needs a governing factor lest it goes out of control.

As grass needs grazers ,other things needs predators ,add something with out a predator ,and soon we have them up to our necks ,

Some times the effects take many years to become noticeable ,sometimes not.

Take away giraffes,and giraffe poop,and the trees will look like hippies ,but more leaves will fall to the ground so more soil will be the result ,but we wont notice much until a few hundred years,have gone by and a changed soil with time may support different plants.

How ever even a species existence may depend on some animal being around ,

There is a tree that only continues if the fruit is eaten by an elephant,and germinates in the elephants poop.And the elephant clears the wood of old trees letting the sun in ,poops and voila!

No elephants and this bread fruit tree will cease to exist.
Just as the disappearance of squirrels will have a marked effect on natural reforestation.

Birds plant all over the place especially fruit trees ,with out these birds ,less will be planted .

A trick in Permaculture to import fruit trees is to have a pole with a bird feeder set in a lightly mulched piece of composted ground .And the visiting birds will leave seedlings behind.

There are millions of examples of interrelationships between fauna &fauna &flora in Nature .

Naturalist will argue it is always wrong to interfere,,And i tend to agree with that 99%.

Others will say, it is progress it wont make a difference ,BUT IT DOES MAKE A DIFFERENCE,whether this difference is harmful ,or will go out of control only time can show us that,and sometimes this can be a very long time before we say damn we should not have done that.

In Africa everybody killed any type of snake and now fields are collapsing because plagues of Norwegian rats have tunneled beneath the fields.
And people again are releasing mole snakes to combat this.

They used to kill vultures but not any more ,people have realized that these carrion eaters are very important to deal with dead bodies( of animals) that other wise would spread disease,and now farmers have vulture restaurants where they dump any carcasses they end up with.

Kids in Mexico killing iguanas,and birds, with slingshots,has resulted in plagues of caterpillars and lots more insects being around .

No Ants means loads of scorpions ,no scorpions loads of cockroaches,and so it goes on .even if we don`t always see it ,everything`s got a job.

To predict what could happen if species disappeared, one has to have in depth knowledge of everything that lives what its interrelationships are and what it`s side effects are.

So the answer to your question is YES it does matter ,if we want things to remain stable ,without any nasty surprises that may come back to bother us Humans ,it is best to leave the Eco systems as intact ,with the least change ,as is possible ,

Now with climatic changes going on we are having drastic changes at micro biotic levels that will effect invasive microbe populations as well as insect population with chain reactions going all the way up the food chain ,and we will be the last to know as usual.

Having said all that there are certain times when we can use the exotic or invasive effect to our advantage .

Wattle,Lantana and Oudhoot for example in Africa ,on the banks of a creek will go crazy and totally block the passage,But the same stuff planted far away on a hill on the edge of the property will provide fire wood forever .

Eucalyptus inside a garden will end up alone ,having killed just about everything with chemicals it releases from the leaves and roots.

But on rocky mountain sides where nothing will grow ,the Eucalyptus will pioneer, break open the rocky surface with its huge roots ,can be killed and a forest can follow in its foots steps

Answer 2

The more diverse the ecosystem, the more stable it is. Imagine a homogenous sort of ecosystem with only a few different species- a new disease could wipe out all of a major species. A new introduced species could wreak havoc. But is there is a lot of dicersity already, one could assume a varietry of trophic levels exist and very complex food webs exist. Ther more links there are in a food web, the more stable it is.

Answer 3

we need species diversity and stability for the functioning of the ecosystem.