Everglades National Park and Big Cypress National Park are conducting a cross-boundary prescribed fire this week in South Florida. So far they have completed 30,000 acres. Everglades is continuing ignitions today and tomorrow, April 4 and 5, 2019.
The south Florida National Parks often ignite prescribed fires with a helicopter-mounted device that drops plastic spheres which ignite after hitting the ground. It’s called a Plastic Sphere Dispenser, or PSD. Much of what the parks burn is vegetation over standing water. If the sphere lands in water it may not ignite the vegetation, but every sphere does not have to be successful.
The burn pattern in the photo below illustrates the paths of several helicopter flight lines. The direction of spread is being determined by a wind blowing from left to right.
When the PSD was first developed several decades ago it was called an
Aerial Ignition Device, or AID. When acquired immune deficiency syndrome, or AIDS, became a serious health issue, firefighters dropped the AID label and renamed it Plastic Sphere Dispenser, or PSD.