What do you think would happen to a habitat if the plant diversity declines? ?

Adding on the plant eaters wouldnt have any plant
s to gobble down on so they would starve. Once the plant eaters die off so would the meat eaters and the whole habitat would literally die or the inhabitants would move somewhere else and still the habitat wouldnt have any inhabitants.

The plant diversity decrease making that plant existence extinct

An egg, or a sack of flour