Desert plants have adapted ways to stay alive. They store water in needles, or inthere hollow inside. There waxy insides don't let water escape. Most plants seeds stay alive underground for along time before it rains. And there spines keep animals from eating them. These all are examples of how plants adapted to the desert.
Some Catastrophic events in the desert can be. Sand storms, when the wind blows sand around in a violent way. This can hurt many plants and animals and be bad for humans living in the area. Or exasperation being 7 to 50 times more then prescription. This can cause no rainfall for a very long time.