and

factors influence biodiversity in ecosystems.

The

eats the

. There is usually a rise and fall in the

population with the

population following the same trend a couple years afterwards. If the predator is dependent on a single prey species, then there will be a clear pattern of

between the two populations.

keep

the numbers of their

and so may reduce damage to plants by grazing and

between prey species.

and many grasses and plants such as dandelions have underground

in the form of thick tubers and rhizomes from which they are able to quickly re-grow after their upper parts have been chomped.

Increasing populations require increasing numbers of

. Livestock

plants whose roots would normally hold the soil together and it simply blows away leaving

which is called desertification.

Economic aid for development of

, shelter belts and planting of

drought resistant resilient grass species.