Air plants can live in a closed terrarium, but it is important to provide them with the right conditions. The closed environment of a terrarium can trap moisture, so it is crucial to ensure proper ventilation to prevent the plants from rotting. Additionally, air plants thrive on air circulation, so it is recommended to open the terrarium for a few hours every week to allow fresh air to reach the plants. Another important factor to consider is the placement of the terrarium. Air plants need sufficient light to photosynthesize, so it is best to place the terrarium in a location with bright, indirect light. Overall, with proper ventilation, light, and care, air plants can thrive in a closed terrarium.